In times of digitalisation, visual assistance systems in assembly are increasingly important. The design of these assembly systems needs to be highly complex to meet the requirements. Due to the increasing number of v...In times of digitalisation, visual assistance systems in assembly are increasingly important. The design of these assembly systems needs to be highly complex to meet the requirements. Due to the increasing number of variants in production processes, as well as shorter innovation and product life cycles, assistance systems should improve quality and reduce complexity of assembly processes. However, many large kitchen manufacturers still assemble kitchen cabinets manually, due to the high variety of components, such as rails and fittings. This paper focuses on the analysis and evaluation of virtual assistance systems to improve quality and usability in individualised kitchen cabinet assembly processes at a large German manufacturer. A solution is identified and detailed.展开更多
Taking a microwave product as an example, a system of integrated assembly structure design is presented. Getting design constraints from the upstream design section through product data management(PDM), the system gen...Taking a microwave product as an example, a system of integrated assembly structure design is presented. Getting design constraints from the upstream design section through product data management(PDM), the system generates the assembly scheme using the case? based method, then assigns the design requirements into each component of the assembly. The detail design for each component can be performed under these design constraints. In order to practise concurrent design, the system sends the final design result to the upstream section and downstream section through PDM to achieve information sharing and integration.展开更多
A root hinge drive assembly is preferred in place of the classical viscous damper in a large solar array system.It has advantages including better deployment control and higher reliability.But the traditional single d...A root hinge drive assembly is preferred in place of the classical viscous damper in a large solar array system.It has advantages including better deployment control and higher reliability.But the traditional single degree of freedom model should be improved.A multiple degrees of freedom dynamics model is presented for the solar arrays deployment to guide the drive assembly design.The established model includes the functions of the torsion springs,the synchronization mechanism and the lock-up impact.A numerical computation method is proposed to solve the dynamics coupling problem.Then considering the drive torque requirement calculated by the proposed model,a root hinge drive assembly is developed based on the reliability engineering design methods,and dual actuators are used as a redundancy design.Pseudo-efficiency is introduced and the major factors influencing the（pseudo-）efficiency of the gear mechanism designed with high reduction ratio are studied for further test data analysis.A ground prototype deployment test is conducted to verify the capacity of the drive assembly.The test device consists of a large-area solar array system and a root hinge drive assembly.The RHDA development time is about 43 s.The theoretical drive torque is compared with the test values which are obtained according to the current data and the reduction efficiency analysis,and the results show that the presented model and the calibration methods are proper enough.展开更多
Target assembly is a key consumable material for producing thin fi lm used in the electronic packaging and devices. The residual stresses induced during the process of soldering are detrimental to the performance of t...Target assembly is a key consumable material for producing thin fi lm used in the electronic packaging and devices. The residual stresses induced during the process of soldering are detrimental to the performance of target assembly. In this work, the intensity and distribution of the soldering residual stress of Co/In/Cu target assembly subjected to a 20 W/(m^2 K) cooling condition corresponding to the actual air cooling process were studied, based on fi nite element simulation and Taguchi method, to optimize the sputtering target assembly. Effects of different control factors, including solder material, thickness of solder layer, target and backing plate, on the soldering residual stress of target assembly are investigated. The maximum residual stress is calculated as 9.28 MPa in the target located at 0.16 mm from target–solder layer interface and at a distance of 0.78 mm from symmetry axis. The optimal design in target assembly has the combination of indium solder material, cobalt target at 12 mm thick, solder layer at 0.8 mm thick, copper backing plate at 15 mm thick. Moreover, solder material is the most important factor among control factors in the target assembly.展开更多
HIV-1 capsid protein(CA) has emerged as a promising target for antiviral treatment considering its structural and regulatory roles in HIV-1 replication. Here, we disclose the design, synthesis, biological assessment, ...HIV-1 capsid protein(CA) has emerged as a promising target for antiviral treatment considering its structural and regulatory roles in HIV-1 replication. Here, we disclose the design, synthesis, biological assessment, and mechanism investigation of a novel series of phenylalanine derivatives gained by further structural modification of PF74. The newly synthesized compounds demonstrated potent anti-HIV activity, represented by 7n displayed anti-HIV-1 activity 6.25-fold better than PF74, and 7h showed anti-HIV-2activity with nearly 139 times improved efficacy over PF74. Surface plasmon resonance(SPR) studies of representative compounds proved that HIV-1 CA was the binding target. Competitive SPR studies using CPSF6 and NUP153 peptides identified that 7n binds to a vital CA assembly interface between the Nterminal and C-terminal domain(NTD-CTD interface). Action stage determination assay revealed that the newly synthesized compounds were antiviral with a dual-stage inhibitory profile. Molecular dynamics(MD) simulations offered the crucial foundation for the hopeful antiviral potency of 7n. Besides, 7m and7n modestly increased metabolic stabilities in human liver microsome(HLM) and human plasma compared to PF74. Overall, these studies offer valuable insights and can regard as the beginning for succedent medicinal chemistry endeavors to discover promising HIV capsid inhibitors with improved efficacy and better drug-like characteristics.展开更多
Assembly process documents record the designers'intention or knowledge.However,common knowl-edge extraction methods are not well suitable for assembly process documents,because of its tabular form and unstructured...Assembly process documents record the designers'intention or knowledge.However,common knowl-edge extraction methods are not well suitable for assembly process documents,because of its tabular form and unstructured natural language texts.In this paper,an assembly semantic entity recognition and relation con-struction method oriented to assembly process documents is proposed.First,the assembly process sentences are extracted from the table through concerned region recognition and cell division,and they will be stored as a key-value object file.Then,the semantic entities in the sentence are identified through the sequence tagging model based on the specific attention mechanism for assembly operation type.The syntactic rules are designed for realizing automatic construction of relation between entities.Finally,by using the self-constructed corpus,it is proved that the sequence tagging model in the proposed method performs better than the mainstream named entity recognition model when handling assembly process design language.The effectiveness of the proposed method is also analyzed through the simulation experiment in the small-scale real scene,compared with manual method.The results show that the proposed method can help designers accumulate knowledge automatically and efficiently.展开更多
To support modular fixture assembly design in virtual environment,a multi-view based modular fixture virtual assembly model is proposed.Instead of squeezing all assembly related information into a single model,three c...To support modular fixture assembly design in virtual environment,a multi-view based modular fixture virtual assembly model is proposed.Instead of squeezing all assembly related information into a single model,three complementary views of assembly model,element information,function and structure,and assembly relationship are proposed to be used.The first view contains the detailed element information,while the other two explicitly capture the hierarchical function relationships and mating relationships respectively.These views are complementary in the sense that each view only contains a specific aspect of assembly related information while together they include required assembly related information.The proposed assembly model is specialized to accommodate the features of modular fixture virtual assembly design and applied in our developed prototype system.展开更多
The layout and assembly of flexible cables play important roles in the design and development of complex electromechanical products.The rationality of cable layout design and the reliability of cable assembly greatly ...The layout and assembly of flexible cables play important roles in the design and development of complex electromechanical products.The rationality of cable layout design and the reliability of cable assembly greatly affect product quality.In this paper,we review the methods of cable layout design,cable assembly process planning,and cable assembly simulation.We first review research on flexible cable layout design(both interactive and automatic).Then,research on the cable assembly process planning,including cable assembly path and manipulation planning,is reviewed.Finally,cable assembly simulation is introduced,which includes general cable information,cable collision detection data,and cable assembly process modeling.Current problems and future research directions are summarized at the end of the paper.展开更多
As an efficient,environmentally friendly,energy-saving construction method,assembled buildings are now widely used in campus building construction.Modular design thinking is system-based design thinking,and its applic...As an efficient,environmentally friendly,energy-saving construction method,assembled buildings are now widely used in campus building construction.Modular design thinking is system-based design thinking,and its application to the design of an assembled teaching building project will comprehensively improve the rationality of the teaching building and component design.The paper focuses on the application of modular design thinking in assembled teaching building design,aiming to provide references for China’s architectural design units,giving full play to the advantages of modular design thinking in future teaching building design projects,and enhancing the level of design,for the construction of the teaching building and the basis of the technical guarantee.展开更多
A versatile and reliable approach is created to fabricate wafer-scale colloidal crystal that consists of a monolayer of hexagonally close-packed polystyrene （PS） spheres. Making wafer-scale colloidal crystal is usua...A versatile and reliable approach is created to fabricate wafer-scale colloidal crystal that consists of a monolayer of hexagonally close-packed polystyrene （PS） spheres. Making wafer-scale colloidal crystal is usually challenging, and it lacks a general theoretical guidance for experimental approaches. To obtain the optimal conditions for self-assembly, a systematic statistical design and analysis method is utilized here, which applies the pick-the-winner rule. This new method combines spin-coating and thermal treatment, and introduces a mixture of glycol and ethanol as a dispersion system to assist self-assembly. By controlling the parameters of self-assembly, we improve the quality of colloidal crystal and reduce the effect of noise on the experiment. To our best knowledge, we are first to pave this path to harvest colloidal crystals. Importantly, a theoretical analysis using an energy landscape base on our process is also developed to provide insights into the PS spheres＇ self-assembly.展开更多
According to the design requirement and on the basis of the principle that the thermal expansion coefficient of the support structure should match with that of the mirror, a lightweight silicon carbide primary mirror ...According to the design requirement and on the basis of the principle that the thermal expansion coefficient of the support structure should match with that of the mirror, a lightweight silicon carbide primary mirror assembly was designed. Finite element analysis combined with the parameter-optimized method was used during the design. Lightweight cell and rigid rib structure were used for the mirror assembly. The static, dynamic and thermal properties of the primary mirror assembly were analyzed. It is shown that after optimization, the lightweight ratio of the silicon carbide mirror is 52.5%, and the rigidity of the silicon carbide structure is high enough to support the required mirror. When temperature changes, the deformation of the mirror surface is in proportion to the temperature difference.展开更多
Based on the principle that the thermal expansion coefficient of the support structure should match that of the mirror, three schemes of primary mirror assembly were designed. Of them, the first is fused silica mirror...Based on the principle that the thermal expansion coefficient of the support structure should match that of the mirror, three schemes of primary mirror assembly were designed. Of them, the first is fused silica mirror plus 4J32 flexible support plus ZTC4 support back plate, the second K9 mirror plus 4J45 flexible support plus ZTC4 support back plate, and the third SiC mirror plus SiC rigid support back plate. A coupled thermo-mechanical analysis of the three primary mirror assemblies was made with finite element method. The results show that the SiC assembly is the best of all schemes in terms of their combination properties due to its elimination of the thermal expansion mismatch between the materials. The analytical results on the cryogenic property of the SiC primary mirror assembly show a higher surface finish of the SiC mirror even under the cryogenic condition.展开更多
This article, in order to improve the assembly of the high-pressure spool, presents an assembly variation identification method achieved by response surface method （RSM）-based model updating using IV-optimal designs...This article, in order to improve the assembly of the high-pressure spool, presents an assembly variation identification method achieved by response surface method （RSM）-based model updating using IV-optimal designs. The method involves screening out non-relevant assembly parameters using IV-optimal designs and the preload of the joints is chosen as the input features and modal frequency is the only response feature. Emphasis is placed on the construction of response surface models including the interactions between the bolted joints by which the non-linear relationship between the assembly variation caused by the changes ofpreload and the output frequency variation is established. By achieving an optimal process of selected variables in the model, assembly variation can be identified. With a case study of the laboratory bolted disks as an example, the proposed method is verified and it gives enough accuracy in variation identification. It has been observed that the first-order response surface models considering the interactions between the bolted joints based on the IV-optimal criterion are adequate for assembly purposes.展开更多
The primary task of top-down assembly design is to define a product抯 detailed physical description satisfying its functional requirements identified during the functional design phase. The implementation of this desi...The primary task of top-down assembly design is to define a product抯 detailed physical description satisfying its functional requirements identified during the functional design phase. The implementation of this design process requires two things, that is, product functional representation and a general assembly model. Product functions are not only the formulation of a customer抯 needs, but also the input data of assembly design. A general assembly model is to support the evolving process of the elaboration of a product structure. The assembly feature of extended concept is taken as a functional carrier, which is a generic relation among assembly-modeled entities. The model of assembly features describes the link between product functions and form features of parts. On the basis of this link, the propagation of design modifications is discussed so as to preserve the functionality and the coherence of the assembly model. The formal model of assembly design process describes the top-down process of creating an assembly model. This formal model is represented by the combination of assembly feature operations, the assembly model and the evaluation process. A design case study is conducted to verify the applicability of the presented approaches.展开更多
This study aimed at designing and assembling an improvised Logic Gates Simulator that can be utilized as an instructional device in basic digital electronics instruction at Caraga State University Cabadbaran Campus, P...This study aimed at designing and assembling an improvised Logic Gates Simulator that can be utilized as an instructional device in basic digital electronics instruction at Caraga State University Cabadbaran Campus, Philippines. This instructional device is believed to enhance the teaching-learning process and would also help address the scarcity of instructional equipment in the school and in the country. Descriptive method of research was employed to come up with the design of the simulator based on the course content of basic digital electronics subject. Acceptability of the improvised simulator based on standards set in this study was?gathered from the experts as respondents using a self-made questionnaire. The data were treated using average weighted mean utilizing parametric scales with verbal descriptions. Findings revealed that the improvised logic gates simulator is highly acceptable in terms of its cost and availability of components,?design and construction,operations, and troubleshooting features. It is concluded that the improvised logic gates simulator is at par in terms of standards on instructional devices based on the evaluation results of experts and is therefore recommended to be used in basic digital electronics instruction. The simulator is an innovative answer and an alternate solution to the scarcity of instructional materials and devices at Caraga State University Cabadbaran Campus.展开更多
With the development of modern science and technology, the construction industry is gradually moving towards an innovative development path. The requirements of modern prefabricated building design are not only the re...With the development of modern science and technology, the construction industry is gradually moving towards an innovative development path. The requirements of modern prefabricated building design are not only the requirements of safety and economy, but also the requirements of energy saving and innovation. BIM technology refers to building information model. By using BIM technology, designers can accurately find out the problems existing in prefabricated building design, quickly work out effective solutions, and reduce the incidence of various difficult problems in the construction process, thus improving the scientificity and rationality of prefabricated building design and comprehensively improving the quality of prefabricated building design schemes. Next, the article discusses the assembly building design method based on BIM technology.展开更多
The parametric part assembly generation method is presented. Based on the parametric part generated by means of constructive-element, through interactively inputting the relationships of the location and the assembly,...The parametric part assembly generation method is presented. Based on the parametric part generated by means of constructive-element, through interactively inputting the relationships of the location and the assembly, and by compiling operations like movement and rotation, the assembly drawing is created so as to implement the occurrence of the parameterizations of the assembly and the part drawing. The data structure of the assembly part and the key technologies of hidden line removal in the implementation of assembly process, etc. , are described in detail.展开更多
Assembly sketch is not only the visualization of abstract function, but alsothe template of detail design. Two kinds of information are needed to create assembly sketch:structure and assembly constraint. Most research...Assembly sketch is not only the visualization of abstract function, but alsothe template of detail design. Two kinds of information are needed to create assembly sketch:structure and assembly constraint. Most researches are aimed at bow to obtain Structures fromfunction, but the problem of how to obtain assembly constraint from function is ignored. Followingthe definition of assembly unit and the classification of function, a hierarchical mapping methodfrom function to assembly constraint is put forward, and the mapping method includes two steps. Thefirst step is the mapping from function to assembly semantics which is assembly expression andaccordant with engineer's design habit. The second one is the mapping from assembly semantics tobasic assembly constraints that are convenient for computer to handle. The mapping method is appliedto DDMS (design, drafting and management system) successfully.展开更多
The current research of machine center accuracy in workspace mainly focuses on the poor geometric error subjected to thermal and gravity load while in operation, however, there are little researches focusing on the ef...The current research of machine center accuracy in workspace mainly focuses on the poor geometric error subjected to thermal and gravity load while in operation, however, there are little researches focusing on the effect of machine center elastic deformations on workspace volume. Therefore, a method called pre-deformation for assembly performance is presented. This method is technically based on the characteristics of machine tool assembly and collaborative computer-aided engineering （CAE） analysis. The research goal is to enhance assembly performance, including straightness, positioning, and angular errors, to realize the precision of the machine tool design. A vertical machine center is taken as an example to illustrate the proposed method. The concept of travel error is defined to obtain the law of the guide surface. The machine center assembly performance is analyzed under cold condition and thermal balance condition to establish the function of pre-deformation. Then, the guide surface in normal direction is processed with the pre-deformation function, and the machine tool assembly performance is measured using a laser interferometer. The measuring results show that the straightness deviation of the Z component in the Y-direction is 158.9% of the allowable value primarily because of the gravity of the spindle head, and the straightness of the X and Y components is minimal. When the machine tool is processed in pre-deformation, the straightness of the Z axis moving component is reduced to 91.2%. This research proposes a pre-deformation machine center assembly method which has sufficient capacity to improving assembly accuracy of machine centers.展开更多
There are many welding fixture layout design problems of flexible parts inbody-in-white assembly process, which directly cause body assemble variation. The fixture layoutdesign quality is mainly influenced by the posi...There are many welding fixture layout design problems of flexible parts inbody-in-white assembly process, which directly cause body assemble variation. The fixture layoutdesign quality is mainly influenced by the position and quantity of fixture locators and clamps. Ageneral analysis model of flexible assembles deformation caused by fixture is set up based on'N-2-l' locating principle, in which the locator and damper are treated as the same fixture layoutelements. An analysis model for the flexible part deformation in fixturing is set up in order toobtain the optimization object function and constraints accordingly. The final fixture elementlayout could be obtained through global optimal research by using improved genetic algorithm, whicheffectively decreases fixture elements layout influence on flexible assembles deformation.展开更多
文摘In times of digitalisation, visual assistance systems in assembly are increasingly important. The design of these assembly systems needs to be highly complex to meet the requirements. Due to the increasing number of variants in production processes, as well as shorter innovation and product life cycles, assistance systems should improve quality and reduce complexity of assembly processes. However, many large kitchen manufacturers still assemble kitchen cabinets manually, due to the high variety of components, such as rails and fittings. This paper focuses on the analysis and evaluation of virtual assistance systems to improve quality and usability in individualised kitchen cabinet assembly processes at a large German manufacturer. A solution is identified and detailed.
文摘Taking a microwave product as an example, a system of integrated assembly structure design is presented. Getting design constraints from the upstream design section through product data management(PDM), the system generates the assembly scheme using the case? based method, then assigns the design requirements into each component of the assembly. The detail design for each component can be performed under these design constraints. In order to practise concurrent design, the system sends the final design result to the upstream section and downstream section through PDM to achieve information sharing and integration.
基金Supported by National Natural Science Foundation of China(Grant Nos.51125020,51105013)the Innovation Foundation of Beihang University for PhD Graduates
文摘A root hinge drive assembly is preferred in place of the classical viscous damper in a large solar array system.It has advantages including better deployment control and higher reliability.But the traditional single degree of freedom model should be improved.A multiple degrees of freedom dynamics model is presented for the solar arrays deployment to guide the drive assembly design.The established model includes the functions of the torsion springs,the synchronization mechanism and the lock-up impact.A numerical computation method is proposed to solve the dynamics coupling problem.Then considering the drive torque requirement calculated by the proposed model,a root hinge drive assembly is developed based on the reliability engineering design methods,and dual actuators are used as a redundancy design.Pseudo-efficiency is introduced and the major factors influencing the（pseudo-）efficiency of the gear mechanism designed with high reduction ratio are studied for further test data analysis.A ground prototype deployment test is conducted to verify the capacity of the drive assembly.The test device consists of a large-area solar array system and a root hinge drive assembly.The RHDA development time is about 43 s.The theoretical drive torque is compared with the test values which are obtained according to the current data and the reduction efficiency analysis,and the results show that the presented model and the calibration methods are proper enough.
基金supported financially by the National Key R&D Program of China (No. 2017YFB0305501)the National Natural Science Foundation of China (No. 51475220)the China Postdoctoral Science Foundation Funded Project (No. 2016M591464)
文摘Target assembly is a key consumable material for producing thin fi lm used in the electronic packaging and devices. The residual stresses induced during the process of soldering are detrimental to the performance of target assembly. In this work, the intensity and distribution of the soldering residual stress of Co/In/Cu target assembly subjected to a 20 W/(m^2 K) cooling condition corresponding to the actual air cooling process were studied, based on fi nite element simulation and Taguchi method, to optimize the sputtering target assembly. Effects of different control factors, including solder material, thickness of solder layer, target and backing plate, on the soldering residual stress of target assembly are investigated. The maximum residual stress is calculated as 9.28 MPa in the target located at 0.16 mm from target–solder layer interface and at a distance of 0.78 mm from symmetry axis. The optimal design in target assembly has the combination of indium solder material, cobalt target at 12 mm thick, solder layer at 0.8 mm thick, copper backing plate at 15 mm thick. Moreover, solder material is the most important factor among control factors in the target assembly.
基金financial support from the National Natural Science Foundation of China(NSFC,Nos.82173677,81773574)the Key Project of NSFC for International Cooperation(No.81420108027)+2 种基金the Shandong Provincial Key Research and Development Project(No.2019JZZY021011)the Science Foundation for Outstanding Young Scholars of Shandong Province(No.ZR2020JQ31)NIH/NIAID grant(No.R01AI150491,Cocklin,PI,Salvino,Co-I)。
文摘HIV-1 capsid protein(CA) has emerged as a promising target for antiviral treatment considering its structural and regulatory roles in HIV-1 replication. Here, we disclose the design, synthesis, biological assessment, and mechanism investigation of a novel series of phenylalanine derivatives gained by further structural modification of PF74. The newly synthesized compounds demonstrated potent anti-HIV activity, represented by 7n displayed anti-HIV-1 activity 6.25-fold better than PF74, and 7h showed anti-HIV-2activity with nearly 139 times improved efficacy over PF74. Surface plasmon resonance(SPR) studies of representative compounds proved that HIV-1 CA was the binding target. Competitive SPR studies using CPSF6 and NUP153 peptides identified that 7n binds to a vital CA assembly interface between the Nterminal and C-terminal domain(NTD-CTD interface). Action stage determination assay revealed that the newly synthesized compounds were antiviral with a dual-stage inhibitory profile. Molecular dynamics(MD) simulations offered the crucial foundation for the hopeful antiviral potency of 7n. Besides, 7m and7n modestly increased metabolic stabilities in human liver microsome(HLM) and human plasma compared to PF74. Overall, these studies offer valuable insights and can regard as the beginning for succedent medicinal chemistry endeavors to discover promising HIV capsid inhibitors with improved efficacy and better drug-like characteristics.
文摘Assembly process documents record the designers'intention or knowledge.However,common knowl-edge extraction methods are not well suitable for assembly process documents,because of its tabular form and unstructured natural language texts.In this paper,an assembly semantic entity recognition and relation con-struction method oriented to assembly process documents is proposed.First,the assembly process sentences are extracted from the table through concerned region recognition and cell division,and they will be stored as a key-value object file.Then,the semantic entities in the sentence are identified through the sequence tagging model based on the specific attention mechanism for assembly operation type.The syntactic rules are designed for realizing automatic construction of relation between entities.Finally,by using the self-constructed corpus,it is proved that the sequence tagging model in the proposed method performs better than the mainstream named entity recognition model when handling assembly process design language.The effectiveness of the proposed method is also analyzed through the simulation experiment in the small-scale real scene,compared with manual method.The results show that the proposed method can help designers accumulate knowledge automatically and efficiently.
文摘To support modular fixture assembly design in virtual environment,a multi-view based modular fixture virtual assembly model is proposed.Instead of squeezing all assembly related information into a single model,three complementary views of assembly model,element information,function and structure,and assembly relationship are proposed to be used.The first view contains the detailed element information,while the other two explicitly capture the hierarchical function relationships and mating relationships respectively.These views are complementary in the sense that each view only contains a specific aspect of assembly related information while together they include required assembly related information.The proposed assembly model is specialized to accommodate the features of modular fixture virtual assembly design and applied in our developed prototype system.
基金the National Defense Fundamental Research Foundation of China(JCKY2017204B502,JCKY2016204A502)and National Natural Science Foundation of China(51935003).
文摘The layout and assembly of flexible cables play important roles in the design and development of complex electromechanical products.The rationality of cable layout design and the reliability of cable assembly greatly affect product quality.In this paper,we review the methods of cable layout design,cable assembly process planning,and cable assembly simulation.We first review research on flexible cable layout design(both interactive and automatic).Then,research on the cable assembly process planning,including cable assembly path and manipulation planning,is reviewed.Finally,cable assembly simulation is introduced,which includes general cable information,cable collision detection data,and cable assembly process modeling.Current problems and future research directions are summarized at the end of the paper.
文摘As an efficient,environmentally friendly,energy-saving construction method,assembled buildings are now widely used in campus building construction.Modular design thinking is system-based design thinking,and its application to the design of an assembled teaching building project will comprehensively improve the rationality of the teaching building and component design.The paper focuses on the application of modular design thinking in assembled teaching building design,aiming to provide references for China’s architectural design units,giving full play to the advantages of modular design thinking in future teaching building design projects,and enhancing the level of design,for the construction of the teaching building and the basis of the technical guarantee.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11504264,51501128,and 61274064)
文摘A versatile and reliable approach is created to fabricate wafer-scale colloidal crystal that consists of a monolayer of hexagonally close-packed polystyrene （PS） spheres. Making wafer-scale colloidal crystal is usually challenging, and it lacks a general theoretical guidance for experimental approaches. To obtain the optimal conditions for self-assembly, a systematic statistical design and analysis method is utilized here, which applies the pick-the-winner rule. This new method combines spin-coating and thermal treatment, and introduces a mixture of glycol and ethanol as a dispersion system to assist self-assembly. By controlling the parameters of self-assembly, we improve the quality of colloidal crystal and reduce the effect of noise on the experiment. To our best knowledge, we are first to pave this path to harvest colloidal crystals. Importantly, a theoretical analysis using an energy landscape base on our process is also developed to provide insights into the PS spheres＇ self-assembly.
文摘According to the design requirement and on the basis of the principle that the thermal expansion coefficient of the support structure should match with that of the mirror, a lightweight silicon carbide primary mirror assembly was designed. Finite element analysis combined with the parameter-optimized method was used during the design. Lightweight cell and rigid rib structure were used for the mirror assembly. The static, dynamic and thermal properties of the primary mirror assembly were analyzed. It is shown that after optimization, the lightweight ratio of the silicon carbide mirror is 52.5%, and the rigidity of the silicon carbide structure is high enough to support the required mirror. When temperature changes, the deformation of the mirror surface is in proportion to the temperature difference.
文摘Based on the principle that the thermal expansion coefficient of the support structure should match that of the mirror, three schemes of primary mirror assembly were designed. Of them, the first is fused silica mirror plus 4J32 flexible support plus ZTC4 support back plate, the second K9 mirror plus 4J45 flexible support plus ZTC4 support back plate, and the third SiC mirror plus SiC rigid support back plate. A coupled thermo-mechanical analysis of the three primary mirror assemblies was made with finite element method. The results show that the SiC assembly is the best of all schemes in terms of their combination properties due to its elimination of the thermal expansion mismatch between the materials. The analytical results on the cryogenic property of the SiC primary mirror assembly show a higher surface finish of the SiC mirror even under the cryogenic condition.
文摘This article, in order to improve the assembly of the high-pressure spool, presents an assembly variation identification method achieved by response surface method （RSM）-based model updating using IV-optimal designs. The method involves screening out non-relevant assembly parameters using IV-optimal designs and the preload of the joints is chosen as the input features and modal frequency is the only response feature. Emphasis is placed on the construction of response surface models including the interactions between the bolted joints by which the non-linear relationship between the assembly variation caused by the changes ofpreload and the output frequency variation is established. By achieving an optimal process of selected variables in the model, assembly variation can be identified. With a case study of the laboratory bolted disks as an example, the proposed method is verified and it gives enough accuracy in variation identification. It has been observed that the first-order response surface models considering the interactions between the bolted joints based on the IV-optimal criterion are adequate for assembly purposes.
基金This is a Sino-France project(1998-2001)supported by French Ministry of Education.
文摘The primary task of top-down assembly design is to define a product抯 detailed physical description satisfying its functional requirements identified during the functional design phase. The implementation of this design process requires two things, that is, product functional representation and a general assembly model. Product functions are not only the formulation of a customer抯 needs, but also the input data of assembly design. A general assembly model is to support the evolving process of the elaboration of a product structure. The assembly feature of extended concept is taken as a functional carrier, which is a generic relation among assembly-modeled entities. The model of assembly features describes the link between product functions and form features of parts. On the basis of this link, the propagation of design modifications is discussed so as to preserve the functionality and the coherence of the assembly model. The formal model of assembly design process describes the top-down process of creating an assembly model. This formal model is represented by the combination of assembly feature operations, the assembly model and the evaluation process. A design case study is conducted to verify the applicability of the presented approaches.
文摘This study aimed at designing and assembling an improvised Logic Gates Simulator that can be utilized as an instructional device in basic digital electronics instruction at Caraga State University Cabadbaran Campus, Philippines. This instructional device is believed to enhance the teaching-learning process and would also help address the scarcity of instructional equipment in the school and in the country. Descriptive method of research was employed to come up with the design of the simulator based on the course content of basic digital electronics subject. Acceptability of the improvised simulator based on standards set in this study was?gathered from the experts as respondents using a self-made questionnaire. The data were treated using average weighted mean utilizing parametric scales with verbal descriptions. Findings revealed that the improvised logic gates simulator is highly acceptable in terms of its cost and availability of components,?design and construction,operations, and troubleshooting features. It is concluded that the improvised logic gates simulator is at par in terms of standards on instructional devices based on the evaluation results of experts and is therefore recommended to be used in basic digital electronics instruction. The simulator is an innovative answer and an alternate solution to the scarcity of instructional materials and devices at Caraga State University Cabadbaran Campus.
文摘With the development of modern science and technology, the construction industry is gradually moving towards an innovative development path. The requirements of modern prefabricated building design are not only the requirements of safety and economy, but also the requirements of energy saving and innovation. BIM technology refers to building information model. By using BIM technology, designers can accurately find out the problems existing in prefabricated building design, quickly work out effective solutions, and reduce the incidence of various difficult problems in the construction process, thus improving the scientificity and rationality of prefabricated building design and comprehensively improving the quality of prefabricated building design schemes. Next, the article discusses the assembly building design method based on BIM technology.
文摘The parametric part assembly generation method is presented. Based on the parametric part generated by means of constructive-element, through interactively inputting the relationships of the location and the assembly, and by compiling operations like movement and rotation, the assembly drawing is created so as to implement the occurrence of the parameterizations of the assembly and the part drawing. The data structure of the assembly part and the key technologies of hidden line removal in the implementation of assembly process, etc. , are described in detail.
基金This project is supported by National Natural Science Foundation of China (No.50075080, No.50275133)Provincial Natural Science Foundation of Zhejiang (No.602039).
文摘Assembly sketch is not only the visualization of abstract function, but alsothe template of detail design. Two kinds of information are needed to create assembly sketch:structure and assembly constraint. Most researches are aimed at bow to obtain Structures fromfunction, but the problem of how to obtain assembly constraint from function is ignored. Followingthe definition of assembly unit and the classification of function, a hierarchical mapping methodfrom function to assembly constraint is put forward, and the mapping method includes two steps. Thefirst step is the mapping from function to assembly semantics which is assembly expression andaccordant with engineer's design habit. The second one is the mapping from assembly semantics tobasic assembly constraints that are convenient for computer to handle. The mapping method is appliedto DDMS (design, drafting and management system) successfully.
基金Supported by National Key Technology Support Program of China(Grant No.2011BAF11B03)National Science and Technology Major Projects of China(Grant No.2012ZX04010-011)
文摘The current research of machine center accuracy in workspace mainly focuses on the poor geometric error subjected to thermal and gravity load while in operation, however, there are little researches focusing on the effect of machine center elastic deformations on workspace volume. Therefore, a method called pre-deformation for assembly performance is presented. This method is technically based on the characteristics of machine tool assembly and collaborative computer-aided engineering （CAE） analysis. The research goal is to enhance assembly performance, including straightness, positioning, and angular errors, to realize the precision of the machine tool design. A vertical machine center is taken as an example to illustrate the proposed method. The concept of travel error is defined to obtain the law of the guide surface. The machine center assembly performance is analyzed under cold condition and thermal balance condition to establish the function of pre-deformation. Then, the guide surface in normal direction is processed with the pre-deformation function, and the machine tool assembly performance is measured using a laser interferometer. The measuring results show that the straightness deviation of the Z component in the Y-direction is 158.9% of the allowable value primarily because of the gravity of the spindle head, and the straightness of the X and Y components is minimal. When the machine tool is processed in pre-deformation, the straightness of the Z axis moving component is reduced to 91.2%. This research proposes a pre-deformation machine center assembly method which has sufficient capacity to improving assembly accuracy of machine centers.
基金This project is supported by National 863 Plan (No.2001AA411140)National Natural Science Foundation of China (No.50175071).
文摘There are many welding fixture layout design problems of flexible parts inbody-in-white assembly process, which directly cause body assemble variation. The fixture layoutdesign quality is mainly influenced by the position and quantity of fixture locators and clamps. Ageneral analysis model of flexible assembles deformation caused by fixture is set up based on'N-2-l' locating principle, in which the locator and damper are treated as the same fixture layoutelements. An analysis model for the flexible part deformation in fixturing is set up in order toobtain the optimization object function and constraints accordingly. The final fixture elementlayout could be obtained through global optimal research by using improved genetic algorithm, whicheffectively decreases fixture elements layout influence on flexible assembles deformation.
