Purpose–The bridge expansion joint(BEJ)is a key device for accommodating spatial displacement at the beam end,and for providing vertical support for running trains passing over the gap between the main bridge and the...Purpose–The bridge expansion joint(BEJ)is a key device for accommodating spatial displacement at the beam end,and for providing vertical support for running trains passing over the gap between the main bridge and the approach bridge.For long-span railway bridges,it must also be coordinated with rail expansion joint(REJ),which is necessary to accommodate the expansion and contraction of,and reducing longitudinal stress in,the rails.The main aim of this study is to present analysis of recent developments in the research and application of BEJs in high-speed railway(HSR)long-span bridges in China,and to propose a performance-based integral design method for BEJs used with REJs,from both theoretical and engineering perspectives.Design/methodology/approach–The study first presents a summary on the application and maintenance of BEJs in HSR long-span bridges in China representing an overview of their state of development.Results of a survey of typical BEJ faults were analyzed,and field testing was conducted on a railway cable-stayed bridge in order to obtain information on the major mechanical characteristics of its BEJ under train load.Based on the above,a performance-based integral design method for BEJs with maximum expansion range 1600 mm(±800 mm),was proposed,covering all stages from overall conceptual design to consideration of detailed structural design issues.The performance of the novel BEJ design thus derived was then verified via theoretical analysis under different scenarios,full-scale model testing,and field testing and commissioning.Findings–Two major types of BEJs,deck-type and through-type,are used in HSR long-span bridges in China.Typical BEJ faults were found to mainly include skewness of steel sleepers at the bridge gap,abnormally large longitudinal frictional resistance,and flexural deformation of the scissor mechanisms.These faults influence BEJ functioning,and thus adversely affect track quality and train running performance at the beam end.Due to their simple and integral structure,deck-type BEJs with expansion range 1200 mm(±600 mm)or less have been favored as a solution offering improved operational conditions,and have emerged as a standard design.However,when the expansion range exceeds the above-mentioned value,special design work becomes necessary.Therefore,based on engineering practice,a performance-based integral design method for BEJs used with REJs was proposed,taking into account four major categories of performance requirements,i.e.,mechanical characteristics,train running quality,durability and insulation performance.Overall BEJ design must mainly consider component strength and the overall stiffness of BEJ;the latter factor in particular has a decisive influence on train running performance at the beam end.Detailed BEJ structural design must stress minimization of the frictional resistance of its sliding surface.The static and dynamic performance of the newlydesigned BEJ with expansion range 1600 mm have been confirmed to be satisfactory,via numerical simulation,full-scale model testing,and field testing and commissioning.Originality/value–This research provides a broad overview of the status of BEJs with large expansion range in HSR long-span bridges in China,along with novel insights into their design.展开更多
Many countries throughout the world have experienced large earthquakes,which cause building damage or collapse.After such earthquakes,structures must be inspected rapidly to judge whether they are safe to reoccupy.To ...Many countries throughout the world have experienced large earthquakes,which cause building damage or collapse.After such earthquakes,structures must be inspected rapidly to judge whether they are safe to reoccupy.To facilitate the inspection process,the authors previously developed a rapid building safety assessment system using sparse acceleration measurements for steel framed buildings.The proposed system modeled nonlinearity in the measurement data using a calibrated simplified lumped-mass model and convolutional neural networks(CNNs),based on which the buildinglevel damage index was estimated rapidly after earthquakes.The proposed system was validated for a nonlinear 3D numerical model of a five-story steel building,and later for a large-scale specimen of an 18-story building in Japan tested on the E-Defense shaking table.However,the applicability of the safety assessment system for reinforced concrete(RC)structures with complex hysteretic material nonlinearity has yet to be explored;the previous approach based on a simplified lumpedmass model with a Bouc-Wen hysteretic model does not accurately represent the inherent nonlinear behavior and resulting damage states of RC structures.This study extends the rapid building safety assessment system to low-rise RC moment resisting frame structures representing typical residential apartments in Japan.First,a safety classification for RC structures based on a damage index consistent with the current state of practice is defined.Then,a 3D nonlinear numerical model of a two-story moment frame structure is created.A simplified lumped-mass nonlinear model is developed and calibrated using the 3D model,incorporating the Takeda degradation model for the RC material nonlinearity.This model is used to simulate the seismic response and associated damage sensitive features(DSF)for random ground motion.The resulting database of responses is used to train a convolutional neural network(CNN)that performs rapid safety assessment.The developed system is validated using the 3D nonlinear analysis model subjected to historical earthquakes.The results indicate the applicability of the proposed system for RC structures following seismic events.展开更多
The need for efficient thermal energy systems has gained significant attention due to the growing global concern about renewable energy resources,particularly in residential buildings.One of the biggest challenges in ...The need for efficient thermal energy systems has gained significant attention due to the growing global concern about renewable energy resources,particularly in residential buildings.One of the biggest challenges in this area is capturing and converting solar energy at maximum efficiency.This requires the use of strong materials and advanced fluids to enhance conversion efficiency while minimizing energy losses.Despite extensive research on thermal energy systems,there remains a limited understanding of how the combined effects of thermal radiation,irreversibility processes,and advanced heat flux models contribute to optimizing solar power performance in residential applications.Addressing these knowledge gaps is critical for advancing the design and implementation of highly efficient thermal energy systems.Owing to its usage,this study investigates the thermal energy and irreversibility processes in the context of solar power systems for residential buildings.Specifically,it explores the influence of thermal radiation and the Cattaneo–Christov heat flux model,considering the interactions over a stretching surface.The study incorporates cross fluid and Maxwell fluid effects into the governing model equations.Utilizing the Galerkin-weighted residual method,the transformed model is solved to understand the impacts on heat distribution.The findings reveal that increased thermal radiation and thermal conductivity significantly enhance heat distribution,offering valuable insights for optimizing solar power system efficiency in residential applications.展开更多
The composite leaf spring landing gear of an electric aircraft is optimized.With the strength and workability as constraints and the minimum structural weight as an objective,the two-stage optimization of the leaf spr...The composite leaf spring landing gear of an electric aircraft is optimized.With the strength and workability as constraints and the minimum structural weight as an objective,the two-stage optimization of the leaf spring landing gear with glass fiber unidirectional prepreg is carried out using a genetic algorithm,namely,the optimization of continuous thickness of layup,and the optimization of the layup sequence and discrete thickness.In the optimization process,the ground loads are calculated according to the structural stiffness of each chromosome,thus the stiffness constraints are relaxed,and the optimization results are compared with those using stiffness constraints.The static experiment verification reveals that the numerical simulation and experimental results are consistent,that is,the optimized leaf spring meets the strength requirements.The results show that the leaf spring landing gear based on two-stage optimization method achieves the objective of weight reduction.展开更多
In this paper,the performance characteristics of ASTM A790 S31803 and ASTM A182 F51 duplex stainless steel were introduced,and the weldabilities were analyzed. The welding repair procedures of thick wall duplex stainl...In this paper,the performance characteristics of ASTM A790 S31803 and ASTM A182 F51 duplex stainless steel were introduced,and the weldabilities were analyzed. The welding repair procedures of thick wall duplex stainless steel were developed by welding procedure qualification. Research shows that the repair welding has less effect on mechanical properties of welded joint, and great influence on phase proportions and pitting corrosion resistance. The test results meet the requirements of project specifications. The repair welding procedure can be used in project,and only one time repair shall be used.展开更多
In the automotive industry, lean project</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Ver...In the automotive industry, lean project</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> and innovation creation come to life by being updated under the control of systematic interdisciplinary process flows. The lean product development process that changes the shell, defined under the light of the variables created by the competitive conditions, is today measured by the value flow efficiency and the global market spread of the final product. Consequently, the lean product development approach, which aims to identify and purify all the wastes that do none value or create value to the system or cause burdens in the new product development process, is shaped by step-by-step approvals in the flow. In the main automotive industry company practices within the scope of the research (3 national, 3 international), the beginning of the concept of lean in design is to define and optimize the steps in the product development process under the value stream map. Therefore, the product function for which the customer has paid for, the function of the new product or the physical structure used to meet the needs in question, the comfort, life, experience, innovations of the scope that constitute the new product concept are planned and verified and implemented in the simplified automotive design stages at the beginning of the lean product development process. In this research, initial automotive design objectives and stages are at the focal point of the innovation and added value creation brought by the concept of </span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">“</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">lean</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">”</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> approach. The research is modelled on the determination of steps that do not create added value together with the points where the flow circuits’ or stems, the process is devalued, the interdisciplinary holistic studies intensify, the information and delay begin and end in the sequential and simultaneous design validation step transition stages, which are examined under the lean approach. As a visual and virtual tool that enables the elaboration of nominal values such as the total duration of the design verification stages and the influence of interdisciplinary stakeholders or the test level of the product design with the new product added, it reveals the value flow or losses. Hence research;from innovation creation and new product design steps, which constitute the initial stages of the lean product development process, to design verification analysis, the efficiency of the automotive company processes within the scope of the research has been measured by comparing using lean automotive design techniques, methods and concepts.展开更多
he design verification steps that take place in today’s automotive industry, which constitute the values of each successive or simultaneous phase in the new product development process, create a complex structure wit...he design verification steps that take place in today’s automotive industry, which constitute the values of each successive or simultaneous phase in the new product development process, create a complex structure with the inclusion of each new technology and discipline. Therefore, step by step, each design verification phase definition in the flow contains important phase transition measurements or approval tolerances that ensure the simplicity and continuity of vehicle development processes. In addition, classification of design verification stages within the framework of this study or evaluation in two classes (static and dynamic) is a new approach, but it is a synthesis with the analysis of the new product development process. The vehicle’s basic structure, which constitutes the ergonomic and functional requirements of the vehicle in a static environment, takes into account the dynamic environment variables with crash or accident tests. Increasing new technology adaptations in the automotive industry have changed the new product development process that performs this function structurally and created the concept of design verification under consecutive or simultaneous process simplicity. From the autonomous driving to the use of alternative energy, possible accident scenarios and design verification phase transitions in the integration of parts and systems of the newly developed vehicle create a new structure that models and directs the lean product development process especially in the automotive industry in the coming days. In the lean product development process that takes place in the automotive industry, the design verification transition steps or the approval-control analysis of the development stages, which form a new and effective approach, are re-modeling the entire flow. Therefore, successful execution of design verification steps used in the control of new interdisciplinary product development phase transitions provides value creation.?Within the scope of this study, the effectiveness of the static and dynamic design verification steps, which are carried out in 5 global automotive companies included in the research, which constitute the stage transitions of the new product development process, has been measured. Apart from the design verification transition stages, the process variables that differ among the automotive companies involved in the research are excluded from the scope of this study. In other words, in field researches in the automotive industry, new vehicle design steps or basic engineering steps in the new product development process steps, while creating independent fixed variables, interdisciplinary collaborations, static and dynamic design verification transition stages they perform, or their sequence in the basic flow, is accepted as a dependent variable. Therefore, in the study, the positive effect of the automotive companies that included the static and dynamic design verification phase transition approvals in the lean product development process was investigated. Under the comparative analysis structure of the research, the effect of automotive companies, which accept international vehicle specifications as static design verification input, on market performance has been examined in depth. The detailed depth in the comparison analysis conducted under the second field studies of the study is due to the prediction of dynamic design verification stages to provide a high impact on the market performance, according to the static verification analysis. The new product development stages of the dependent variables were fixed and the flow-oriented?“effect”?of the independent variables in the basic process influenced by the design verification activities was analyzed under the new automotive industry company comparisons. In addition, the impact of the automotive design activities that make up the comparison analysis of the research on the scope of the lean product development stage and its effect on the basic process flow has been demonstrated competition-oriented. Therefore, sub-variables, options, criteria, results, which form a defined comparison problem, create basic test values that affect the problem.展开更多
In this study, it is aimed to determine the ranking importance levels of the stages to be taken into consideration for new product development on a global scale in the automotive design process. New product design act...In this study, it is aimed to determine the ranking importance levels of the stages to be taken into consideration for new product development on a global scale in the automotive design process. New product design activity and stage-gate process differences between local automotive firms (serial production factory and stage-gate department in Turkey) and global automotive companies (serial production factory and stage-gate department in Turkey) are examined comparatively in the research area. In the automotive industry, which has been developing for a century, the question of how the local company products operating in the last sixty years have not been able to spread globally or how to develop global products is the background question of the research. For this purpose, one on one interviews were held with the managers of 3 national and 3 international automotive companies, who worked in the same region and who had previously designed a new vehicle, with design and product development departments.?According to?the data obtained by the AHP (Analytic Hierarchy Process) in the automotive design process, the importance of the criteria that should be taken into account for global product development has revealed. According to the results of the study, it was found that design validation stages were the most important globalization criterion in automotive design process as a new study area. In the comprehensive survey of the study, no other publication has been encountered to measure or evaluate the stages in the automotive design and new product development process in other sectors, including the vehicle industry. As in every industry sector, in the automotive industry, with the new product companies provide market development or competitive advantage. The new product is the life channel of a company and in the realization of this new vehicle;the disciplines of the automotive industry are formed by a hundred years of experience.展开更多
This paper presents an optimal vehicle and seat suspension design for a half-car vehicle model to reduce human-body vibration (whole-body vibration). A genetic algorithm is applied to search for the optimal parameters...This paper presents an optimal vehicle and seat suspension design for a half-car vehicle model to reduce human-body vibration (whole-body vibration). A genetic algorithm is applied to search for the optimal parameters of the seat and vehicle suspension. The desired objective is proposed as the minimization of a multi-objective function formed by the combination of seat suspension working space (seat suspension deflection), head acceleration, and seat mass acceleration to achieve the best comfort of the driver. With the aid of Matlab/Simulink software, a simulation model is achieved. In solving this problem, the genetic algorithms have consistently found near-optimal solutions within specified parameters ranges for several independent runs. For validation, the solution obtained by GA was compared to the ones of the passive suspensions through sinusoidal excitation of the seat suspension system for the currently used suspension systems.展开更多
Reverse Engineering (RE) involves the use of techniques aimed to retrieve information about manufactured products, not only regarding geometries, but also materials and functionality. Today, even if several RE techniq...Reverse Engineering (RE) involves the use of techniques aimed to retrieve information about manufactured products, not only regarding geometries, but also materials and functionality. Today, even if several RE techniques are known, many of them still leave the object unusable to analyze. Nevertheless, other alternatives to this problem allows for obtaining a Digital or Virtual Model (VM) via the three-dimen- sional scanning. Getting the VM of an item, via scanning or not, can offer many possibilities to digital analysis (FEM). Furthermore, starting from VM, it is possible to achieve the physical reproduction of an element, part or workpiece—in the same or different materials—using Additive Manufacturing (AM) technologies. This enables to improve the product through a redesign process. In this paper, a RE based methodology is proposed for redesigning a tool for contour milling, after comparing different microscopy based techniques, 3D-Scanner tools and CAD-CAGD utilities for generating a Virtual Model of the newly designed mill.展开更多
The linear seat suspension is considered due to the low cost consideration therefore, the optimal linear seat suspension design method can be used for this purpose. In this paper, the design of a passive vehicle seat ...The linear seat suspension is considered due to the low cost consideration therefore, the optimal linear seat suspension design method can be used for this purpose. In this paper, the design of a passive vehicle seat suspension system was handled in the framework of linear optimization. The variance of the dynamic load resulting from the vibrating vehicle operating at a constant speed was used as the performance measure of a suspension system. Using 4-DOF human body model developed by Abbas et al., with linear seat suspension and coupled with half car model. A genetic algorithm is applied to solve the linear optimization problem. The optimal design parameters of the seat suspension systems obtained are kse = 3 012.5 N/m and cse = 1 210.4 N.s/m, respectively.展开更多
Rising energy costs and growing environmental awareness motivate a critical revision of the design of distillation units. Systematic design techniques, such as the rectification body, column profile map, and temperatu...Rising energy costs and growing environmental awareness motivate a critical revision of the design of distillation units. Systematic design techniques, such as the rectification body, column profile map, and temperature collocation methods, require exact knowledge of all pinch points in a particular system, because these stationary points delineate the possible composition trajectories realizable in separation columns. This paper demonstrates novel methods for rigorously determining all pinch points for the constant relative volatility, ideal and non-ideal systems. Constant relative volatility and ideal solution systems are transformed into one-dimensional polynomial and nonlinear functions, regardless of the number of the components. A deflation method is proposed to locate all zeros in ideal and non-ideal zeotropic problems. For more challenging non-ideal problems, a novel hybrid sequential niche algorithm is used to solve hard azeotropic problems successfully. Finally, the design implications of these pinch point locations are investigated to show how new separation configurations can be devised. Methodically the paper points out the use of rigorous pinch point computations in conjunction with continuous composition profiles for robust distillation design.展开更多
The function of decision-making in the management of new product development and vehicle design activities is achieved by defining, constructing or evaluating the outcome-oriented, and most effective steps from the su...The function of decision-making in the management of new product development and vehicle design activities is achieved by defining, constructing or evaluating the outcome-oriented, and most effective steps from the sub-steps that form this basic process. The choice of the sub-stages of the basic process or the decision of how to do a job gains importance in terms of the efficiency of the firm’s activities. Therefore, the decision making function is one of the basic elements involved in the formation and development of the basic processes that can comply with the market dynamics of firms. With the new product being developed, the selection, the current editing or the evaluation of the steps that make up the vehicle design activities for the automotive industry companies that exist and compete in the market, bring about significant gains. In the manufacturing industry, the design of the vehicle determines the market spread, while the competitive conditions are driven by the new or improved product decision. In both cases, the automotive industry firms must know the stages of the most appropriate vehicle design in their own right, and the steps of forming new project dynamics must be devised in this direction. In this study, the result oriented activity of the current vehicle design phases used in the automotive industry companies is determined and the order of importance of the stages is listed. For this purpose, under the same conditions of competition (the same market, the same class vehicles develops and manufactures), 4 in the automotive firm administration, a total of 40 employees (4 × 10 process manager) with the vehicle design was evaluated by determining the effectiveness of the use of the stage. At this stage, analytic hierarchy methods applied to each of the phases are explored in practice instead of the use of the significance level automotive company. Study of the vehicle design phase of the automotive industry: structure, process modifications or new project reveals the important values to be configured according to the size.展开更多
The household drill is named 90 Degree, designed by Industrial Design Pilot Program Center(Hereinafter referred to as IDPPC) of Luxun Academy of Fine Arts(Hereinafter referred to as LAFA), which is the only national p...The household drill is named 90 Degree, designed by Industrial Design Pilot Program Center(Hereinafter referred to as IDPPC) of Luxun Academy of Fine Arts(Hereinafter referred to as LAFA), which is the only national pilot program center in Chinese industrial design field. 90 Degree is designed for home environment, it helps inexperience users, such as women and the elderly, complete the operation easily, and it makes sure that safe operation and assistance users solve the precise punching, location, storage trash and other operations. According to research among users who can understand or manipulate a drill, the designers find problems of users from the user central perspective, and then they integrate product innovative design methods to propose solutions. When the designers intend to design 90 Degree, they attempt using the user behavior record and analysis system, and start ergonomics study in subjects by double hands operation analysis, using gesture analysis, details of work analysis, time and motion study, etc; meanwhile taking advantages of user experience analysis, behavior intention analysis to do user subjective perceptual evaluation. The functions, structure, shape, color, material, details of 90 Degree should be consistent with the standard of usability evaluation. There are two characteristics in 90 Degree, the first one is a transparent cover installed in front of the drill, which can collect the dust, rubbish when drilling and keep the work environment clean. So it is applicable for households. When the transparent cover of the drill is removed, it also can be used as a normal hand drill; the second one is the shape of 90 Degree makes it and the operating surface fitting together, thus enhancing the stability in operation, so it is best for inexperienced users. When 90 Degree contacts with the operating surface, it can emit the laser ray which helps the user to punch accurately, and make array punch more easily. After obtaining the data, charts, creating Shadow observation by the designers, they make a comprehensive evaluation on research results; verification advantages of 90 Degree meet the requirement of usability, reducing operating failure rate; and increasing safety factors. 90 Degree, in 2011, wined German Red Dot Design Award, which had become a representative excellent design example to resolve several drilling difficulties. The designers introduce ergonomics theory into design practice, and use scientific program and methods to evaluate the products which is useful to the development and promotion of products.展开更多
The aero-engine design process is highly iterative,multidisciplinary in nature and complex.The success of any engine design depends on best exploiting and considering the interactions among the numerous traditional en...The aero-engine design process is highly iterative,multidisciplinary in nature and complex.The success of any engine design depends on best exploiting and considering the interactions among the numerous traditional engineering disciplines such as aerodynamics and structures.More emphasis has been placed lately on system integration,cross disciplines leveraging of tools and multi-disciplinary-optimization at the preliminary design phase.This paper investigates the automation of the airfoil generation process,referred to as Rapid Airfoil3D(RAF-3D),for uncooled high pressure turbine blades at the preliminary design phase.This approach uses the TAML(Turbine Aero Mean Line)program in parallel with a database of previously designed P&WC airfoils,in-house design rules and best practices to define a pre-detailed airfoil shape which can be fed back to other analytical groups for pre-detail analyses,such as for structural integrity and vibrations.Resulting airfoil shapes have been aerodynamically validated using an in-house three dimensional Reynolds averaged Navier-Stokes code.RAF-3D will shorten the turnaround time for Pratt&Whitney turbine aerodynamics group to provide a preliminary3D airfoil shape to turbine structures group by up to a factor of ten.Additionally,the preliminary assessments of stress and vibration specialists will be more accurate as their assessments will be based on an airfoil that has had inputs from all functional groups even though it is"first pass"design.展开更多
The main purpose of this study is to design and implement a small-scale biogas digest system, which can provide a certain amount of natural gas (N.G.). The percentage of methane gases emissions according to the variou...The main purpose of this study is to design and implement a small-scale biogas digest system, which can provide a certain amount of natural gas (N.G.). The percentage of methane gases emissions according to the various research studies is around 25% of the total emission gases of the waste materials. For all industrialized nations, food waste costs approximately $680 billion/year. The dramatic increase in population and the waste of organic and non-organic materials lead to the use of biomass energy as the source of the renewable energy system to produce a natural gas (N.G.), which can be utilized in cooking or commercialized for the public. The burn out of the waste and the garbage materials causes tremendous pollution and global warming;however, utilizing the Biogas Digest System (BDS) will stop polluting the surrounding environment. The amount of natural gases production was measured for various atmospheric conditions. The important findings of this study are the amount of N.G., which can be increased by mixing two different types of organic waste materials.展开更多
In the automotive concept design stages, functionally positioning the newly introduced autonomous technologies or remodelling the vehicle accordingly and evaluating the steps or determining the workload together with ...In the automotive concept design stages, functionally positioning the newly introduced autonomous technologies or remodelling the vehicle accordingly and evaluating the steps or determining the workload together with the collaboration intensity in the current flow is the initial step for the entire process efficiency. Therefore, the main purpose of the research is to reveal the effects of the autonomous technologies, which are newly included in the automotive concept design stages in automotive manufacturing industry companies that continue their lives under heavy competition conditions, according to the order of importance. The objective of this research is to both increase the efficiency of automotive concept design stages and to determine the measurement of the effects of new autonomous vehicle technologies in practice. Under the AHP method used in the research, the automotive concept design stages constitute the alternatives in the order of importance of the working structure, as well as the application variables of autonomous vehicle technologies, the criteria of the mathematical model. In addition, the research method modelled in the study, under the AHP mathematical model, reveals the performances or order of importance of the automotive concept design stages under autonomous technologies. Therefore, the resulting process performances constitute important inputs for efficiency and optimization studies under different research approaches. When the results of the study are examined, due to the high level of influence on the new vehicle concept design performance in automotive industry companies, the adaptation or application steps of autonomous vehicle technologies create new needs in the whole process. The determination of innovation creation clusters in the design process steps or the selection of the density of new technology adaptation in the stages and the order of importance provide a competitive advantage along with optimization in the basic functions of the automotive industry companies. However, the determination of new workload clusters in the mentioned automotive concept design process steps or the effect of autonomous technologies in the design stages, selection, transfer from theory to practice, multiple conflicting criteria and uncertain parameters create a very complex situation. For all these reasons, the Analytical Hierarchy Process (AHP), which is one of the widely used multi-criteria decision-making tools, is considered as a suitable approach for creating such order of importance and solving problems. In this study, an AHP mathematical model was created that determines the workload clusters created by autonomous vehicle technology applications that have just begun to guide the automotive concept design process, which is the main function of automotive manufacturing industry companies. Therefore, in line with the innovations, changes and adequacy criteria created by the current automotive concept design stages in the new autonomous vehicle technology adaptation, a stage order of importance has been selected.展开更多
New road transportation systems solutions create significant changes in existing automotive manufacturing industry products and technologies, from design to use. The conveniences within the framework of new appro...New road transportation systems solutions create significant changes in existing automotive manufacturing industry products and technologies, from design to use. The conveniences within the framework of new approaches brought by autonomous vehicle technologies primarily make individuals transition from driver duty to passenger and high-comfort alternative travel technologies. Therefore, the research: defining the path followed by the autonomous vehicle technologies, which lead to the development of the said new life model and automotive products within the future fiction, in the stages of designing new concept vehicles in practice or measuring the effect on the processes constitute important values for the future prediction of this sector. In addition, the research has focused on the effects of interdisciplinary studies at the automotive concept design stages, which are at the beginning of today’s lean and new product development process, where innovation goals or technologies emerge with more concrete needs. New autonomous vehicle technologies and the main purpose of revealing the interdisciplinary studies created by new disciplines in the current automotive concept design stages make significant contributions to the optimization of the lean product development process and value creation. For this reason, the automotive manufacturing industry, which is on the eve of a major transformation with the said new autonomous vehicle technologies;determining the needs or sustainable position in the flow of digital perception and orientation systems;determining value creation criteria related to the functioning of automotive concept design processes or new acceptance criteria through one-on-one interviews in the field;constitutes the focus of the research. The research has examined the new interdisciplinary studies and effects of new autonomous vehicle technologies in the automotive concept design phase, which is the first step of lean product development, with local and global automotive industry company comparisons in operation. Therefore, the differences and similarities between the concept design stages of global automotive companies that are both co-developers of new autonomous vehicle technologies and manufacturing automotive products and local automotive manufacturing companies that only assemble them determine the future competitive structuring of the industry.展开更多
The global automotive industry is giving a difficult and common test in order to create advanced life models in the near future plans or scenarios that include current autonomous vehicle technologies. Therefore, the m...The global automotive industry is giving a difficult and common test in order to create advanced life models in the near future plans or scenarios that include current autonomous vehicle technologies. Therefore, the main purpose of the research is to comparatively evaluate the impact of autonomous vehicle technologies, which are newly included in the automotive manufacturing industry under sustainable competition, on lean product development processes, value acquisition and preservation, in different organizational structures in the approach. Although mergers or brand acquisitions in the global automotive industry create joint R & D (Research Development) or joint new P & D (Product Development) process structures for the development of autonomous vehicle technologies, heavy competition continues in the market. These new processes create different needs for the merger and partnership of the renewed traffic infrastructures under national and international regulations, and for the implementation of the new autonomous life model. Firm and brand marriages, mergers or acquisitions in today’s automotive industry have ensured the high diffusion of lean product development processes under the stream of value creation or preservation carried out specific to the company under competition. Brand mergers in automotive industry companies struggling to survive under high competition create new work disciplines, professions, and engineering flow steps in lean product development processes. However, lean product development processes driven by technological innovation under simplification have resulted in the integration of parts and systems within the autonomous vehicle design structure, as well as creating new interdisciplinary value streams or different stakeholders. Therefore, the research revealed the significant effects of lean product development processes on the value stream in the automotive industry, on the mixed and lean product development process structure formed by new or existing vehicle systems (conventional vehicle) under the penetration of each existing and new discipline. This research compares the efficient operation steps of the process stakeholders in the autonomous vehicle design parts or systems containing innovation and new technology together with the value stream in the lean product development process, and the new process stakeholder’s business-oriented global and local automotive industry companies. New autonomous vehicle technologies, together with their unique software, hardware and development analysis, have been involved in the lean product development process with their interdisciplinary studies or expertise. Therefore, the study firstly focused on the technologies in environmental use together with the new basic features of autonomous vehicles, and then examined in depth the new or existing disciplines and interdisciplinary basic structure that these innovations affect under the value stream in the lean product development process. In addition, micro-level results and recommendations were shared, shedding light on how autonomous vehicle levels will create changes in the new product development process.展开更多
A detailed design methodology of a micro-scale 2-DOF energy harvesting device that can harvest human motion energy of low frequency and wide bandwidth is developed. Based on the concept of the 2-DOF vibration absorber...A detailed design methodology of a micro-scale 2-DOF energy harvesting device that can harvest human motion energy of low frequency and wide bandwidth is developed. Based on the concept of the 2-DOF vibration absorber, device parameters are selected to harvest energy at low frequency of 1-10 Hz and wide bandwidth with ±20% of the mean frequency, which matches the human motion. The device dimensions are limited to 40 × 30 × 10 mm3 to fit with the human wrist size. Then, a finite element model is developed to investigate the system performance with the selected parameters. When subjected to harmonic excitation of 1 g, the proposed 2-DOF device is able to provide a power of at least 10 μW in between the two close resonant peaks of 4 Hz and 6 Hz, which is the target frequency range. The device shows very high power per square frequency compared with the reported harvesters.展开更多
基金National Key R&D Program of China(2022YFB2602900)R&D Fund Project of China Academy of Railway Sciences Corporation Limited(2021YJ084)+2 种基金Project of Science and Technology R&D Program of China Railway(2016G002-K)R&D Fund Project of China Railway Major Bridge Reconnaissance&Design Institute Co.,Ltd.(2021)R&D Fund Project of China Railway Shanghai Group(2021141).
文摘Purpose–The bridge expansion joint(BEJ)is a key device for accommodating spatial displacement at the beam end,and for providing vertical support for running trains passing over the gap between the main bridge and the approach bridge.For long-span railway bridges,it must also be coordinated with rail expansion joint(REJ),which is necessary to accommodate the expansion and contraction of,and reducing longitudinal stress in,the rails.The main aim of this study is to present analysis of recent developments in the research and application of BEJs in high-speed railway(HSR)long-span bridges in China,and to propose a performance-based integral design method for BEJs used with REJs,from both theoretical and engineering perspectives.Design/methodology/approach–The study first presents a summary on the application and maintenance of BEJs in HSR long-span bridges in China representing an overview of their state of development.Results of a survey of typical BEJ faults were analyzed,and field testing was conducted on a railway cable-stayed bridge in order to obtain information on the major mechanical characteristics of its BEJ under train load.Based on the above,a performance-based integral design method for BEJs with maximum expansion range 1600 mm(±800 mm),was proposed,covering all stages from overall conceptual design to consideration of detailed structural design issues.The performance of the novel BEJ design thus derived was then verified via theoretical analysis under different scenarios,full-scale model testing,and field testing and commissioning.Findings–Two major types of BEJs,deck-type and through-type,are used in HSR long-span bridges in China.Typical BEJ faults were found to mainly include skewness of steel sleepers at the bridge gap,abnormally large longitudinal frictional resistance,and flexural deformation of the scissor mechanisms.These faults influence BEJ functioning,and thus adversely affect track quality and train running performance at the beam end.Due to their simple and integral structure,deck-type BEJs with expansion range 1200 mm(±600 mm)or less have been favored as a solution offering improved operational conditions,and have emerged as a standard design.However,when the expansion range exceeds the above-mentioned value,special design work becomes necessary.Therefore,based on engineering practice,a performance-based integral design method for BEJs used with REJs was proposed,taking into account four major categories of performance requirements,i.e.,mechanical characteristics,train running quality,durability and insulation performance.Overall BEJ design must mainly consider component strength and the overall stiffness of BEJ;the latter factor in particular has a decisive influence on train running performance at the beam end.Detailed BEJ structural design must stress minimization of the frictional resistance of its sliding surface.The static and dynamic performance of the newlydesigned BEJ with expansion range 1600 mm have been confirmed to be satisfactory,via numerical simulation,full-scale model testing,and field testing and commissioning.Originality/value–This research provides a broad overview of the status of BEJs with large expansion range in HSR long-span bridges in China,along with novel insights into their design.
基金supported by a fellowship from Design Department of Taisei Corporation。
文摘Many countries throughout the world have experienced large earthquakes,which cause building damage or collapse.After such earthquakes,structures must be inspected rapidly to judge whether they are safe to reoccupy.To facilitate the inspection process,the authors previously developed a rapid building safety assessment system using sparse acceleration measurements for steel framed buildings.The proposed system modeled nonlinearity in the measurement data using a calibrated simplified lumped-mass model and convolutional neural networks(CNNs),based on which the buildinglevel damage index was estimated rapidly after earthquakes.The proposed system was validated for a nonlinear 3D numerical model of a five-story steel building,and later for a large-scale specimen of an 18-story building in Japan tested on the E-Defense shaking table.However,the applicability of the safety assessment system for reinforced concrete(RC)structures with complex hysteretic material nonlinearity has yet to be explored;the previous approach based on a simplified lumpedmass model with a Bouc-Wen hysteretic model does not accurately represent the inherent nonlinear behavior and resulting damage states of RC structures.This study extends the rapid building safety assessment system to low-rise RC moment resisting frame structures representing typical residential apartments in Japan.First,a safety classification for RC structures based on a damage index consistent with the current state of practice is defined.Then,a 3D nonlinear numerical model of a two-story moment frame structure is created.A simplified lumped-mass nonlinear model is developed and calibrated using the 3D model,incorporating the Takeda degradation model for the RC material nonlinearity.This model is used to simulate the seismic response and associated damage sensitive features(DSF)for random ground motion.The resulting database of responses is used to train a convolutional neural network(CNN)that performs rapid safety assessment.The developed system is validated using the 3D nonlinear analysis model subjected to historical earthquakes.The results indicate the applicability of the proposed system for RC structures following seismic events.
基金funded by Universiti Teknikal Malaysia Melaka through the Tabung Penerbitan Jurnal(S11017).
文摘The need for efficient thermal energy systems has gained significant attention due to the growing global concern about renewable energy resources,particularly in residential buildings.One of the biggest challenges in this area is capturing and converting solar energy at maximum efficiency.This requires the use of strong materials and advanced fluids to enhance conversion efficiency while minimizing energy losses.Despite extensive research on thermal energy systems,there remains a limited understanding of how the combined effects of thermal radiation,irreversibility processes,and advanced heat flux models contribute to optimizing solar power performance in residential applications.Addressing these knowledge gaps is critical for advancing the design and implementation of highly efficient thermal energy systems.Owing to its usage,this study investigates the thermal energy and irreversibility processes in the context of solar power systems for residential buildings.Specifically,it explores the influence of thermal radiation and the Cattaneo–Christov heat flux model,considering the interactions over a stretching surface.The study incorporates cross fluid and Maxwell fluid effects into the governing model equations.Utilizing the Galerkin-weighted residual method,the transformed model is solved to understand the impacts on heat distribution.The findings reveal that increased thermal radiation and thermal conductivity significantly enhance heat distribution,offering valuable insights for optimizing solar power system efficiency in residential applications.
基金the Natural Science Foundation of Liaoning (No. 20180550824)。
文摘The composite leaf spring landing gear of an electric aircraft is optimized.With the strength and workability as constraints and the minimum structural weight as an objective,the two-stage optimization of the leaf spring landing gear with glass fiber unidirectional prepreg is carried out using a genetic algorithm,namely,the optimization of continuous thickness of layup,and the optimization of the layup sequence and discrete thickness.In the optimization process,the ground loads are calculated according to the structural stiffness of each chromosome,thus the stiffness constraints are relaxed,and the optimization results are compared with those using stiffness constraints.The static experiment verification reveals that the numerical simulation and experimental results are consistent,that is,the optimized leaf spring meets the strength requirements.The results show that the leaf spring landing gear based on two-stage optimization method achieves the objective of weight reduction.
文摘In this paper,the performance characteristics of ASTM A790 S31803 and ASTM A182 F51 duplex stainless steel were introduced,and the weldabilities were analyzed. The welding repair procedures of thick wall duplex stainless steel were developed by welding procedure qualification. Research shows that the repair welding has less effect on mechanical properties of welded joint, and great influence on phase proportions and pitting corrosion resistance. The test results meet the requirements of project specifications. The repair welding procedure can be used in project,and only one time repair shall be used.
文摘In the automotive industry, lean project</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> and innovation creation come to life by being updated under the control of systematic interdisciplinary process flows. The lean product development process that changes the shell, defined under the light of the variables created by the competitive conditions, is today measured by the value flow efficiency and the global market spread of the final product. Consequently, the lean product development approach, which aims to identify and purify all the wastes that do none value or create value to the system or cause burdens in the new product development process, is shaped by step-by-step approvals in the flow. In the main automotive industry company practices within the scope of the research (3 national, 3 international), the beginning of the concept of lean in design is to define and optimize the steps in the product development process under the value stream map. Therefore, the product function for which the customer has paid for, the function of the new product or the physical structure used to meet the needs in question, the comfort, life, experience, innovations of the scope that constitute the new product concept are planned and verified and implemented in the simplified automotive design stages at the beginning of the lean product development process. In this research, initial automotive design objectives and stages are at the focal point of the innovation and added value creation brought by the concept of </span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">“</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">lean</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">”</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> approach. The research is modelled on the determination of steps that do not create added value together with the points where the flow circuits’ or stems, the process is devalued, the interdisciplinary holistic studies intensify, the information and delay begin and end in the sequential and simultaneous design validation step transition stages, which are examined under the lean approach. As a visual and virtual tool that enables the elaboration of nominal values such as the total duration of the design verification stages and the influence of interdisciplinary stakeholders or the test level of the product design with the new product added, it reveals the value flow or losses. Hence research;from innovation creation and new product design steps, which constitute the initial stages of the lean product development process, to design verification analysis, the efficiency of the automotive company processes within the scope of the research has been measured by comparing using lean automotive design techniques, methods and concepts.
文摘he design verification steps that take place in today’s automotive industry, which constitute the values of each successive or simultaneous phase in the new product development process, create a complex structure with the inclusion of each new technology and discipline. Therefore, step by step, each design verification phase definition in the flow contains important phase transition measurements or approval tolerances that ensure the simplicity and continuity of vehicle development processes. In addition, classification of design verification stages within the framework of this study or evaluation in two classes (static and dynamic) is a new approach, but it is a synthesis with the analysis of the new product development process. The vehicle’s basic structure, which constitutes the ergonomic and functional requirements of the vehicle in a static environment, takes into account the dynamic environment variables with crash or accident tests. Increasing new technology adaptations in the automotive industry have changed the new product development process that performs this function structurally and created the concept of design verification under consecutive or simultaneous process simplicity. From the autonomous driving to the use of alternative energy, possible accident scenarios and design verification phase transitions in the integration of parts and systems of the newly developed vehicle create a new structure that models and directs the lean product development process especially in the automotive industry in the coming days. In the lean product development process that takes place in the automotive industry, the design verification transition steps or the approval-control analysis of the development stages, which form a new and effective approach, are re-modeling the entire flow. Therefore, successful execution of design verification steps used in the control of new interdisciplinary product development phase transitions provides value creation.?Within the scope of this study, the effectiveness of the static and dynamic design verification steps, which are carried out in 5 global automotive companies included in the research, which constitute the stage transitions of the new product development process, has been measured. Apart from the design verification transition stages, the process variables that differ among the automotive companies involved in the research are excluded from the scope of this study. In other words, in field researches in the automotive industry, new vehicle design steps or basic engineering steps in the new product development process steps, while creating independent fixed variables, interdisciplinary collaborations, static and dynamic design verification transition stages they perform, or their sequence in the basic flow, is accepted as a dependent variable. Therefore, in the study, the positive effect of the automotive companies that included the static and dynamic design verification phase transition approvals in the lean product development process was investigated. Under the comparative analysis structure of the research, the effect of automotive companies, which accept international vehicle specifications as static design verification input, on market performance has been examined in depth. The detailed depth in the comparison analysis conducted under the second field studies of the study is due to the prediction of dynamic design verification stages to provide a high impact on the market performance, according to the static verification analysis. The new product development stages of the dependent variables were fixed and the flow-oriented?“effect”?of the independent variables in the basic process influenced by the design verification activities was analyzed under the new automotive industry company comparisons. In addition, the impact of the automotive design activities that make up the comparison analysis of the research on the scope of the lean product development stage and its effect on the basic process flow has been demonstrated competition-oriented. Therefore, sub-variables, options, criteria, results, which form a defined comparison problem, create basic test values that affect the problem.
文摘In this study, it is aimed to determine the ranking importance levels of the stages to be taken into consideration for new product development on a global scale in the automotive design process. New product design activity and stage-gate process differences between local automotive firms (serial production factory and stage-gate department in Turkey) and global automotive companies (serial production factory and stage-gate department in Turkey) are examined comparatively in the research area. In the automotive industry, which has been developing for a century, the question of how the local company products operating in the last sixty years have not been able to spread globally or how to develop global products is the background question of the research. For this purpose, one on one interviews were held with the managers of 3 national and 3 international automotive companies, who worked in the same region and who had previously designed a new vehicle, with design and product development departments.?According to?the data obtained by the AHP (Analytic Hierarchy Process) in the automotive design process, the importance of the criteria that should be taken into account for global product development has revealed. According to the results of the study, it was found that design validation stages were the most important globalization criterion in automotive design process as a new study area. In the comprehensive survey of the study, no other publication has been encountered to measure or evaluate the stages in the automotive design and new product development process in other sectors, including the vehicle industry. As in every industry sector, in the automotive industry, with the new product companies provide market development or competitive advantage. The new product is the life channel of a company and in the realization of this new vehicle;the disciplines of the automotive industry are formed by a hundred years of experience.
文摘This paper presents an optimal vehicle and seat suspension design for a half-car vehicle model to reduce human-body vibration (whole-body vibration). A genetic algorithm is applied to search for the optimal parameters of the seat and vehicle suspension. The desired objective is proposed as the minimization of a multi-objective function formed by the combination of seat suspension working space (seat suspension deflection), head acceleration, and seat mass acceleration to achieve the best comfort of the driver. With the aid of Matlab/Simulink software, a simulation model is achieved. In solving this problem, the genetic algorithms have consistently found near-optimal solutions within specified parameters ranges for several independent runs. For validation, the solution obtained by GA was compared to the ones of the passive suspensions through sinusoidal excitation of the seat suspension system for the currently used suspension systems.
文摘Reverse Engineering (RE) involves the use of techniques aimed to retrieve information about manufactured products, not only regarding geometries, but also materials and functionality. Today, even if several RE techniques are known, many of them still leave the object unusable to analyze. Nevertheless, other alternatives to this problem allows for obtaining a Digital or Virtual Model (VM) via the three-dimen- sional scanning. Getting the VM of an item, via scanning or not, can offer many possibilities to digital analysis (FEM). Furthermore, starting from VM, it is possible to achieve the physical reproduction of an element, part or workpiece—in the same or different materials—using Additive Manufacturing (AM) technologies. This enables to improve the product through a redesign process. In this paper, a RE based methodology is proposed for redesigning a tool for contour milling, after comparing different microscopy based techniques, 3D-Scanner tools and CAD-CAGD utilities for generating a Virtual Model of the newly designed mill.
文摘The linear seat suspension is considered due to the low cost consideration therefore, the optimal linear seat suspension design method can be used for this purpose. In this paper, the design of a passive vehicle seat suspension system was handled in the framework of linear optimization. The variance of the dynamic load resulting from the vibrating vehicle operating at a constant speed was used as the performance measure of a suspension system. Using 4-DOF human body model developed by Abbas et al., with linear seat suspension and coupled with half car model. A genetic algorithm is applied to solve the linear optimization problem. The optimal design parameters of the seat suspension systems obtained are kse = 3 012.5 N/m and cse = 1 210.4 N.s/m, respectively.
文摘Rising energy costs and growing environmental awareness motivate a critical revision of the design of distillation units. Systematic design techniques, such as the rectification body, column profile map, and temperature collocation methods, require exact knowledge of all pinch points in a particular system, because these stationary points delineate the possible composition trajectories realizable in separation columns. This paper demonstrates novel methods for rigorously determining all pinch points for the constant relative volatility, ideal and non-ideal systems. Constant relative volatility and ideal solution systems are transformed into one-dimensional polynomial and nonlinear functions, regardless of the number of the components. A deflation method is proposed to locate all zeros in ideal and non-ideal zeotropic problems. For more challenging non-ideal problems, a novel hybrid sequential niche algorithm is used to solve hard azeotropic problems successfully. Finally, the design implications of these pinch point locations are investigated to show how new separation configurations can be devised. Methodically the paper points out the use of rigorous pinch point computations in conjunction with continuous composition profiles for robust distillation design.
文摘The function of decision-making in the management of new product development and vehicle design activities is achieved by defining, constructing or evaluating the outcome-oriented, and most effective steps from the sub-steps that form this basic process. The choice of the sub-stages of the basic process or the decision of how to do a job gains importance in terms of the efficiency of the firm’s activities. Therefore, the decision making function is one of the basic elements involved in the formation and development of the basic processes that can comply with the market dynamics of firms. With the new product being developed, the selection, the current editing or the evaluation of the steps that make up the vehicle design activities for the automotive industry companies that exist and compete in the market, bring about significant gains. In the manufacturing industry, the design of the vehicle determines the market spread, while the competitive conditions are driven by the new or improved product decision. In both cases, the automotive industry firms must know the stages of the most appropriate vehicle design in their own right, and the steps of forming new project dynamics must be devised in this direction. In this study, the result oriented activity of the current vehicle design phases used in the automotive industry companies is determined and the order of importance of the stages is listed. For this purpose, under the same conditions of competition (the same market, the same class vehicles develops and manufactures), 4 in the automotive firm administration, a total of 40 employees (4 × 10 process manager) with the vehicle design was evaluated by determining the effectiveness of the use of the stage. At this stage, analytic hierarchy methods applied to each of the phases are explored in practice instead of the use of the significance level automotive company. Study of the vehicle design phase of the automotive industry: structure, process modifications or new project reveals the important values to be configured according to the size.
文摘The household drill is named 90 Degree, designed by Industrial Design Pilot Program Center(Hereinafter referred to as IDPPC) of Luxun Academy of Fine Arts(Hereinafter referred to as LAFA), which is the only national pilot program center in Chinese industrial design field. 90 Degree is designed for home environment, it helps inexperience users, such as women and the elderly, complete the operation easily, and it makes sure that safe operation and assistance users solve the precise punching, location, storage trash and other operations. According to research among users who can understand or manipulate a drill, the designers find problems of users from the user central perspective, and then they integrate product innovative design methods to propose solutions. When the designers intend to design 90 Degree, they attempt using the user behavior record and analysis system, and start ergonomics study in subjects by double hands operation analysis, using gesture analysis, details of work analysis, time and motion study, etc; meanwhile taking advantages of user experience analysis, behavior intention analysis to do user subjective perceptual evaluation. The functions, structure, shape, color, material, details of 90 Degree should be consistent with the standard of usability evaluation. There are two characteristics in 90 Degree, the first one is a transparent cover installed in front of the drill, which can collect the dust, rubbish when drilling and keep the work environment clean. So it is applicable for households. When the transparent cover of the drill is removed, it also can be used as a normal hand drill; the second one is the shape of 90 Degree makes it and the operating surface fitting together, thus enhancing the stability in operation, so it is best for inexperienced users. When 90 Degree contacts with the operating surface, it can emit the laser ray which helps the user to punch accurately, and make array punch more easily. After obtaining the data, charts, creating Shadow observation by the designers, they make a comprehensive evaluation on research results; verification advantages of 90 Degree meet the requirement of usability, reducing operating failure rate; and increasing safety factors. 90 Degree, in 2011, wined German Red Dot Design Award, which had become a representative excellent design example to resolve several drilling difficulties. The designers introduce ergonomics theory into design practice, and use scientific program and methods to evaluate the products which is useful to the development and promotion of products.
文摘The aero-engine design process is highly iterative,multidisciplinary in nature and complex.The success of any engine design depends on best exploiting and considering the interactions among the numerous traditional engineering disciplines such as aerodynamics and structures.More emphasis has been placed lately on system integration,cross disciplines leveraging of tools and multi-disciplinary-optimization at the preliminary design phase.This paper investigates the automation of the airfoil generation process,referred to as Rapid Airfoil3D(RAF-3D),for uncooled high pressure turbine blades at the preliminary design phase.This approach uses the TAML(Turbine Aero Mean Line)program in parallel with a database of previously designed P&WC airfoils,in-house design rules and best practices to define a pre-detailed airfoil shape which can be fed back to other analytical groups for pre-detail analyses,such as for structural integrity and vibrations.Resulting airfoil shapes have been aerodynamically validated using an in-house three dimensional Reynolds averaged Navier-Stokes code.RAF-3D will shorten the turnaround time for Pratt&Whitney turbine aerodynamics group to provide a preliminary3D airfoil shape to turbine structures group by up to a factor of ten.Additionally,the preliminary assessments of stress and vibration specialists will be more accurate as their assessments will be based on an airfoil that has had inputs from all functional groups even though it is"first pass"design.
文摘The main purpose of this study is to design and implement a small-scale biogas digest system, which can provide a certain amount of natural gas (N.G.). The percentage of methane gases emissions according to the various research studies is around 25% of the total emission gases of the waste materials. For all industrialized nations, food waste costs approximately $680 billion/year. The dramatic increase in population and the waste of organic and non-organic materials lead to the use of biomass energy as the source of the renewable energy system to produce a natural gas (N.G.), which can be utilized in cooking or commercialized for the public. The burn out of the waste and the garbage materials causes tremendous pollution and global warming;however, utilizing the Biogas Digest System (BDS) will stop polluting the surrounding environment. The amount of natural gases production was measured for various atmospheric conditions. The important findings of this study are the amount of N.G., which can be increased by mixing two different types of organic waste materials.
文摘In the automotive concept design stages, functionally positioning the newly introduced autonomous technologies or remodelling the vehicle accordingly and evaluating the steps or determining the workload together with the collaboration intensity in the current flow is the initial step for the entire process efficiency. Therefore, the main purpose of the research is to reveal the effects of the autonomous technologies, which are newly included in the automotive concept design stages in automotive manufacturing industry companies that continue their lives under heavy competition conditions, according to the order of importance. The objective of this research is to both increase the efficiency of automotive concept design stages and to determine the measurement of the effects of new autonomous vehicle technologies in practice. Under the AHP method used in the research, the automotive concept design stages constitute the alternatives in the order of importance of the working structure, as well as the application variables of autonomous vehicle technologies, the criteria of the mathematical model. In addition, the research method modelled in the study, under the AHP mathematical model, reveals the performances or order of importance of the automotive concept design stages under autonomous technologies. Therefore, the resulting process performances constitute important inputs for efficiency and optimization studies under different research approaches. When the results of the study are examined, due to the high level of influence on the new vehicle concept design performance in automotive industry companies, the adaptation or application steps of autonomous vehicle technologies create new needs in the whole process. The determination of innovation creation clusters in the design process steps or the selection of the density of new technology adaptation in the stages and the order of importance provide a competitive advantage along with optimization in the basic functions of the automotive industry companies. However, the determination of new workload clusters in the mentioned automotive concept design process steps or the effect of autonomous technologies in the design stages, selection, transfer from theory to practice, multiple conflicting criteria and uncertain parameters create a very complex situation. For all these reasons, the Analytical Hierarchy Process (AHP), which is one of the widely used multi-criteria decision-making tools, is considered as a suitable approach for creating such order of importance and solving problems. In this study, an AHP mathematical model was created that determines the workload clusters created by autonomous vehicle technology applications that have just begun to guide the automotive concept design process, which is the main function of automotive manufacturing industry companies. Therefore, in line with the innovations, changes and adequacy criteria created by the current automotive concept design stages in the new autonomous vehicle technology adaptation, a stage order of importance has been selected.
文摘New road transportation systems solutions create significant changes in existing automotive manufacturing industry products and technologies, from design to use. The conveniences within the framework of new approaches brought by autonomous vehicle technologies primarily make individuals transition from driver duty to passenger and high-comfort alternative travel technologies. Therefore, the research: defining the path followed by the autonomous vehicle technologies, which lead to the development of the said new life model and automotive products within the future fiction, in the stages of designing new concept vehicles in practice or measuring the effect on the processes constitute important values for the future prediction of this sector. In addition, the research has focused on the effects of interdisciplinary studies at the automotive concept design stages, which are at the beginning of today’s lean and new product development process, where innovation goals or technologies emerge with more concrete needs. New autonomous vehicle technologies and the main purpose of revealing the interdisciplinary studies created by new disciplines in the current automotive concept design stages make significant contributions to the optimization of the lean product development process and value creation. For this reason, the automotive manufacturing industry, which is on the eve of a major transformation with the said new autonomous vehicle technologies;determining the needs or sustainable position in the flow of digital perception and orientation systems;determining value creation criteria related to the functioning of automotive concept design processes or new acceptance criteria through one-on-one interviews in the field;constitutes the focus of the research. The research has examined the new interdisciplinary studies and effects of new autonomous vehicle technologies in the automotive concept design phase, which is the first step of lean product development, with local and global automotive industry company comparisons in operation. Therefore, the differences and similarities between the concept design stages of global automotive companies that are both co-developers of new autonomous vehicle technologies and manufacturing automotive products and local automotive manufacturing companies that only assemble them determine the future competitive structuring of the industry.
文摘The global automotive industry is giving a difficult and common test in order to create advanced life models in the near future plans or scenarios that include current autonomous vehicle technologies. Therefore, the main purpose of the research is to comparatively evaluate the impact of autonomous vehicle technologies, which are newly included in the automotive manufacturing industry under sustainable competition, on lean product development processes, value acquisition and preservation, in different organizational structures in the approach. Although mergers or brand acquisitions in the global automotive industry create joint R & D (Research Development) or joint new P & D (Product Development) process structures for the development of autonomous vehicle technologies, heavy competition continues in the market. These new processes create different needs for the merger and partnership of the renewed traffic infrastructures under national and international regulations, and for the implementation of the new autonomous life model. Firm and brand marriages, mergers or acquisitions in today’s automotive industry have ensured the high diffusion of lean product development processes under the stream of value creation or preservation carried out specific to the company under competition. Brand mergers in automotive industry companies struggling to survive under high competition create new work disciplines, professions, and engineering flow steps in lean product development processes. However, lean product development processes driven by technological innovation under simplification have resulted in the integration of parts and systems within the autonomous vehicle design structure, as well as creating new interdisciplinary value streams or different stakeholders. Therefore, the research revealed the significant effects of lean product development processes on the value stream in the automotive industry, on the mixed and lean product development process structure formed by new or existing vehicle systems (conventional vehicle) under the penetration of each existing and new discipline. This research compares the efficient operation steps of the process stakeholders in the autonomous vehicle design parts or systems containing innovation and new technology together with the value stream in the lean product development process, and the new process stakeholder’s business-oriented global and local automotive industry companies. New autonomous vehicle technologies, together with their unique software, hardware and development analysis, have been involved in the lean product development process with their interdisciplinary studies or expertise. Therefore, the study firstly focused on the technologies in environmental use together with the new basic features of autonomous vehicles, and then examined in depth the new or existing disciplines and interdisciplinary basic structure that these innovations affect under the value stream in the lean product development process. In addition, micro-level results and recommendations were shared, shedding light on how autonomous vehicle levels will create changes in the new product development process.
文摘A detailed design methodology of a micro-scale 2-DOF energy harvesting device that can harvest human motion energy of low frequency and wide bandwidth is developed. Based on the concept of the 2-DOF vibration absorber, device parameters are selected to harvest energy at low frequency of 1-10 Hz and wide bandwidth with ±20% of the mean frequency, which matches the human motion. The device dimensions are limited to 40 × 30 × 10 mm3 to fit with the human wrist size. Then, a finite element model is developed to investigate the system performance with the selected parameters. When subjected to harmonic excitation of 1 g, the proposed 2-DOF device is able to provide a power of at least 10 μW in between the two close resonant peaks of 4 Hz and 6 Hz, which is the target frequency range. The device shows very high power per square frequency compared with the reported harvesters.
