In this work, a survey of companies has been produc ed from a questionnaire and in-depth inter-views. The aimof the paper is to give a current view of the use of DES (Discrete- Event Simulation) in the indust ry. The ...In this work, a survey of companies has been produc ed from a questionnaire and in-depth inter-views. The aimof the paper is to give a current view of the use of DES (Discrete- Event Simulation) in the indust ry. The companies have been selected in a wide range in e.g. size, capital turno ver and employees. The survey was restricted to Sweden, although the results may be applicable to other countries with similar industrial structure. Some of the companies investigated are also multinational with branches around the world. T o illustrate the differences in production systems different sectors have be en investigated, e.g. the manufacturing industry and energy sector. The manufact uring systems generally differ in that the energy sector is more known for high reliability in their systems and the manufacturing sector tends to work more wit h lean production. Previous surveys of manufacturing efficiency illustrate different aspects. Accor ding to one survey, more than one-third (34%) of the disturbances in two countr ies (the U.S. and Finland) were mainly caused by design-based errors and flaws. The survey also showed the scope of safety problems experienced in the implemen tation and use of flexible manufacturing systems (Jrvinen et al., 1996). Another survey in Germany reports a gap between users and non-users of DES. Man y companies that are not familiar with simulation are not aware of its benefits. The study suggested integrating simulation into the planning processes as a reg ular tool. So far, DES is mostly used in system planning, resource planning and scheduling and production planning (Hirschberg & Heitmann, 1997). The disposition of the accomplished questionnaire had been multiple-choice ques tions in a strict order. The respondents gave their views on what the interviewe r considered relevant for the survey. The questionnaire was mailed to 220 person s in May 2001; a second round for unanswered surveys was dispatched in August 20 01. Replies came from 114 respondents; thus, the reply rate to all questionnaire s sent out was 52%. The replies came in from 80 different companies. Questionswere raised regarding what kinds of decisions are taken from a simulation projec t and questions were also asked regarding the tool itself. Some common problems encountered based on the authors’ knowledge were asked in the questionnaire. The questions were sent to those who had reasonable knowledge of how to work with D ES. Supplementary in-depth interviews were also accomplished. On the question if DES facilitates the decision-making process 79% of totally 3 8 answered to a very large or a large extent. Regarding the question if DES is a useful tool for measuring the availability of equipment for example system verification 73% of 33 responded to a very large or a large extent. A majority o f the respondents genuinely see an advantage with the use of simulation, which i s an important result from the study. The cost reduction aspect of the productio n is also an advantage of DES. On the question eight answered to a very large ex tent and 23 to a large extent of total 39 replies. The question demonstrates tha t the results of a simulation model are indeed used in the real world. Finally, in the question of DES is used for staffing it is indicated that it is not so co mmonly used as for other functions asked for. The staffing issue requires good k nowledge about time measurement of manual labor. The option, however, to include manual work in a simulation model is in many programs extensive and must be a v aluable option to evaluate work intensive parts of production lines and their im provement. To conclude, it could be mentioned that DES is a tool with potential. The use is increasing and 12 of 80 companies investigated in Sweden 2001 are using it, an increase compared to previous stud-ies. Of those 12 companies, four are using t he tool to a large extent. The main advantage according to the survey beside the visualization part is that the knowledge about a system is investigated and doc umented.展开更多
The Riyadh metro project is one of the current megaprojects that aim to improve the transit systems in Saudi Arabia.It consists of several metro lines with a total length of 176 km and 85 stations.The viaducts are con...The Riyadh metro project is one of the current megaprojects that aim to improve the transit systems in Saudi Arabia.It consists of several metro lines with a total length of 176 km and 85 stations.The viaducts are considered as one of the main construction elements in the metro lines.Four methods for viaducts construction have been used in the Riyadh metro project:precast beam,full span launching method,cast on-site,and segment method(precast segment method and BCM(balanced cantilever method)).The viaducts work consumes a large portion of a project’s time and cost.Furthermore,the competitive nature of the construction industry increases the need to improve the efficiency of construction performance.Accordingly,this paper takes the initial steps toward increasing the efficiency of viaduct construction methods through simulation.Simulation of construction processes provides a systematic tool that can be used for determining the resources,time,and cost of these processes.The simulation processes should focus on the main activities affecting this element’s execution for viaducts construction,such as segment storage,handling,transporting,and installation.This study highlights the viaducts construction methods and develops general discrete-event simulation models for the most commonly used viaducts construction methods in the Riyadh metro using AnyLogic simulation software.The simulation models visualize and capture the interaction between the different activities and resources in a viaduct construction.Consequently,the construction drawbacks can be identified.Furthermore,the simulation model can be manipulated by adding assumptions to develop more efficient construction methods in terms of time and cost in such projects.展开更多
The goal of this paper is to provide an approach to investigate the variation of fiber quantity in a certain cross-section of the drafting zone. This model with discrete-event simulation( DES)method was presented to s...The goal of this paper is to provide an approach to investigate the variation of fiber quantity in a certain cross-section of the drafting zone. This model with discrete-event simulation( DES)method was presented to simulate the dynamic drafting process. This model described the behavior of individual fibers,which was divided into four phases and simulated by corresponding modules. Three sets of processing conditions in industry were simulated and demonstrated the applications of this model. The comparison between experiments and simulation results could also validate this model. This model could be used to simulate various drafting process with appropriate drafting settings.展开更多
Object-oriented world-view provides a natural and powerful paradignl for expressing system elements and their dynamic behaviour for discrete-event simulation. Simulation gives the critical ability to study the dynamic...Object-oriented world-view provides a natural and powerful paradignl for expressing system elements and their dynamic behaviour for discrete-event simulation. Simulation gives the critical ability to study the dynamic behaviour of the models that are defined with object-voriented means. This paper first examines the ways of applying the object-oriented world-view to three major discrete simulation modelling approaches, then considers the process and merits of object-oriented simulation modelling.展开更多
Because of the challenge of compounding lightweight,high-strength Ti/Al alloys due to their considerable disparity in properties,Al 6063 as intermediate layer was proposed to fabricate TC4/Al 6063/Al 7075 three-layer ...Because of the challenge of compounding lightweight,high-strength Ti/Al alloys due to their considerable disparity in properties,Al 6063 as intermediate layer was proposed to fabricate TC4/Al 6063/Al 7075 three-layer composite plate by explosive welding.The microscopic properties of each bonding interface were elucidated through field emission scanning electron microscope and electron backscattered diffraction(EBSD).A methodology combining finite element method-smoothed particle hydrodynamics(FEM-SPH)and molecular dynamics(MD)was proposed for the analysis of the forming and evolution characteristics of explosive welding interfaces at multi-scale.The results demonstrate that the bonding interface morphologies of TC4/Al 6063 and Al 6063/Al 7075 exhibit a flat and wavy configuration,without discernible defects or cracks.The phenomenon of grain refinement is observed in the vicinity of the two bonding interfaces.Furthermore,the degree of plastic deformation of TC4 and Al 7075 is more pronounced than that of Al 6063 in the intermediate layer.The interface morphology characteristics obtained by FEM-SPH simulation exhibit a high degree of similarity to the experimental results.MD simulations reveal that the diffusion of interfacial elements predominantly occurs during the unloading phase,and the simulated thickness of interfacial diffusion aligns well with experimental outcomes.The introduction of intermediate layer in the explosive welding process can effectively produce high-quality titanium/aluminum alloy composite plates.Furthermore,this approach offers a multi-scale simulation strategy for the study of explosive welding bonding interfaces.展开更多
Recent progress in microwave absorption materials stimulates the extensive exploration of rare earth oxide materials.Herein,we report the synthesis of a hollow sphere-based carbon material compounded with rare earth o...Recent progress in microwave absorption materials stimulates the extensive exploration of rare earth oxide materials.Herein,we report the synthesis of a hollow sphere-based carbon material compounded with rare earth oxides.Hollow N-doped carbon nano-spheres loaded ceria composites(H-NC@CeO_(2))were designed and prepared by the template method,combined with in-situ coating,pyrolysis and chemical etching.By controlling the loading content of H-NC@CeO_(2)and adjusting the impedance matching of the material,the H-NC@CeO_(2)/PS(polystyrene)composite exhibited a minimum reflection loss(RL)of-50.8 dB and an effective absorption band-width(EAB)of 4.64 GHz at a filler ratio of 20wt%and a thickness of 2 mm.In accordance with measured electromagnetic parameters,simulations using the high frequency structure simulator(HFSS)software were conducted to investigate the impact of the honeycomb structure on the electromagnetic wave performance of H-NC@CeO_(2)/PS.By calculating the surface electric field and the material’s bulk loss density,the mechanism of electromagnetic loss for the honeycomb structure was elaborated.A method for structural design and man-ufacturing of broadband absorbing devices was proposed and a broadband absorber with an EAB of 11.9 GHz was prepared.This study presents an innovative approach to designing advanced electromagnetic(EM)wave absorbing materials with broad absorption band-widths.展开更多
Large size titanium alloy parts are widely used in aerospace.However,they are difficult to manufacture using mechanical cutting technology because of severe tool wear.Electrochemical jet machining is a promising techn...Large size titanium alloy parts are widely used in aerospace.However,they are difficult to manufacture using mechanical cutting technology because of severe tool wear.Electrochemical jet machining is a promising technology to achieve high efficiency,because it has high machining flexibility and no machining tool wear.However,reports on the macro electrochemical jet machining of large size titanium alloy parts are very scarce,because it is difficult to achieve effective constraint of the flow field in macro electrochemical jet machining.In addition,titanium alloy is very sensitive to fluctuation of the flow field,and a turbulent flow field would lead to serious stray corrosion.This paper reports a series of investigations of the electrochemical jet machining of titanium alloy parts.Based on the flow analysis and experiments,the machining flow field was effectively constrained.TB6 titanium alloy part with a perimeter of one meter was machined.The machined surface was smooth with no obvious machining defects.The machining process was particularly stable with no obvious spark discharge.The research provides a reference for the application of electrochemical jet machining technology to achieve large allowance material removal in the machining of large titanium alloy parts.展开更多
The pre-wetting of aggregate surface is a means to improve the interface performance of SBS modified asphalt and aggregate.The effect of pre-wetting technology on the interaction between SBS modified asphalt and aggre...The pre-wetting of aggregate surface is a means to improve the interface performance of SBS modified asphalt and aggregate.The effect of pre-wetting technology on the interaction between SBS modified asphalt and aggregate was analyzed by molecular dynamics simulation.The diffusion coefficient and concentration distribution of SBS modified asphalt on aggregate surface are included.The simulation results show that the diffusion coefficient of the aggregate surface of SBS modified asphalt is increased by 47.6%and 70.5%respectively after 110#asphalt and 130#asphalt are pre-wetted.The concentration distribution of SBS modified asphalt on the aggregate surface after pre-wetting is more uniform.According to the results of interface energy calculation,the interface energy of SBS modified bitumen and aggregate can be increased by about 5%after pre-wetting.According to the results of molecular dynamics simulation,the pre-wetting technology can effectively improve the interface workability of SBS modified bitumen and aggregate,so as to improve the interface performance.展开更多
Burial dissolution is a critical diagenetic process influencing ultra-deep carbonate reservoir development and preservation.Artificial carbonate samples with different internal structures were prepared,and high-temper...Burial dissolution is a critical diagenetic process influencing ultra-deep carbonate reservoir development and preservation.Artificial carbonate samples with different internal structures were prepared,and high-temperature and highpressure dissolution kinetic simulations were conducted.The results demonstrate that the intensity of burial dissolution is controlled by temperature and pressure,while tectonic-fluid activity influences the development pattern of burial dissolution,ultimately determining the direction of its differential modification.Extensive burial dissolution is likely to occur primarily at relatively shallow depths,significantly influencing reservoir formation,preservation,modification,and adjustment.The development of faults facilitates the maintenance of the intensity of burial dissolution.The maximum intensity of burial dissolution occurs at the tips and overlap zones of faults and intersections of multiple faults.The larger the scale of the faults,the more conducive it is to the development of burial dissolution.Burial dissolution fosters the formation of fault networks characterized by enhanced reservoir capacity and permeability.Burial dissolution controlled by episodic tectonic-fluid activity is a plausible explanation for forming the Tarim Basin's ultra-deep fault-controlled“stringbead-like”reservoirs.展开更多
The graded density impactor(GDI)dynamic loading technique is crucial for acquiring the dynamic physical property parameters of materials used in weapons.The accuracy and timeliness of GDI structural design are key to ...The graded density impactor(GDI)dynamic loading technique is crucial for acquiring the dynamic physical property parameters of materials used in weapons.The accuracy and timeliness of GDI structural design are key to achieving controllable stress-strain rate loading.In this study,we have,for the first time,combined one-dimensional fluid computational software with machine learning methods.We first elucidated the mechanisms by which GDI structures control stress and strain rates.Subsequently,we constructed a machine learning model to create a structure-property response surface.The results show that altering the loading velocity and interlayer thickness has a pronounced regulatory effect on stress and strain rates.In contrast,the impedance distribution index and target thickness have less significant effects on stress regulation,although there is a matching relationship between target thickness and interlayer thickness.Compared with traditional design methods,the machine learning approach offers a10^(4)—10^(5)times increase in efficiency and the potential to achieve a global optimum,holding promise for guiding the design of GDI.展开更多
The 2025 M_(w)7.7 Myanmar earthquake highlighted the challenge of near-fault seismic intensity field reconstruction due to sparse seismic networks.To address this limitation,a framework was proposed integrating seismi...The 2025 M_(w)7.7 Myanmar earthquake highlighted the challenge of near-fault seismic intensity field reconstruction due to sparse seismic networks.To address this limitation,a framework was proposed integrating seismic wave simulation with a data-constrained finite-fault rupture model.The constraint is implemented by identifying the optimal ground motion models(GMMs)through a scoring system that selects the best-fit GMMs to mid-and far-field China Earthquake Networks Center(CENC)seismic network data;and applying the optimal GMMs to refine the rupture model parameters for near-fault intensity field simulation.The simulated near-fault seismic intensity field reproduces seismic intensities collected from Myanmar’s sparse seismic network and concentrated in≥Ⅷintensity zones within 50 km of the projected fault plane;and identifies abnormal intensity regions exhibiting≥Ⅹintensity along the Meiktila-Naypyidaw corridor and near Shwebo that are attributed to soft soil amplification effects and near-fault directivity.This framework can also be applied to post-earthquake assessments in other similar regions.展开更多
A suction casting experiment was conducted on Zr_(55)Cu_(30)Al_(10)Ni_(5)(at%)amorphous alloy.Using ProCAST software,numerical simulations were performed to analyze the filling and solidification processes.The velocit...A suction casting experiment was conducted on Zr_(55)Cu_(30)Al_(10)Ni_(5)(at%)amorphous alloy.Using ProCAST software,numerical simulations were performed to analyze the filling and solidification processes.The velocity field during the filling process and the temperature field during the solidification process of the alloy melt under different process parameters were obtained.Based on the simulation results,a Zr-based amorphous alloy micro-gear was prepared via casting.The results indicate that increasing the suction casting temperature enhances the fluidity of alloy melt but induces unstable flow rate during filling,which is detrimental to complete filling.Zr-based amorphous micro-gears with a module of 0.6 mm,a tooth top diameter of 8 mm,and 10 teeth were prepared through the suction casting.X-ray diffraction and differential scanning calorimetry analyses confirm that the fabricated micro-gear exhibits characteristic amorphous structural features,demonstrating well-defined geometrical contours and satisfactory forming completeness.展开更多
文摘In this work, a survey of companies has been produc ed from a questionnaire and in-depth inter-views. The aimof the paper is to give a current view of the use of DES (Discrete- Event Simulation) in the indust ry. The companies have been selected in a wide range in e.g. size, capital turno ver and employees. The survey was restricted to Sweden, although the results may be applicable to other countries with similar industrial structure. Some of the companies investigated are also multinational with branches around the world. T o illustrate the differences in production systems different sectors have be en investigated, e.g. the manufacturing industry and energy sector. The manufact uring systems generally differ in that the energy sector is more known for high reliability in their systems and the manufacturing sector tends to work more wit h lean production. Previous surveys of manufacturing efficiency illustrate different aspects. Accor ding to one survey, more than one-third (34%) of the disturbances in two countr ies (the U.S. and Finland) were mainly caused by design-based errors and flaws. The survey also showed the scope of safety problems experienced in the implemen tation and use of flexible manufacturing systems (Jrvinen et al., 1996). Another survey in Germany reports a gap between users and non-users of DES. Man y companies that are not familiar with simulation are not aware of its benefits. The study suggested integrating simulation into the planning processes as a reg ular tool. So far, DES is mostly used in system planning, resource planning and scheduling and production planning (Hirschberg & Heitmann, 1997). The disposition of the accomplished questionnaire had been multiple-choice ques tions in a strict order. The respondents gave their views on what the interviewe r considered relevant for the survey. The questionnaire was mailed to 220 person s in May 2001; a second round for unanswered surveys was dispatched in August 20 01. Replies came from 114 respondents; thus, the reply rate to all questionnaire s sent out was 52%. The replies came in from 80 different companies. Questionswere raised regarding what kinds of decisions are taken from a simulation projec t and questions were also asked regarding the tool itself. Some common problems encountered based on the authors’ knowledge were asked in the questionnaire. The questions were sent to those who had reasonable knowledge of how to work with D ES. Supplementary in-depth interviews were also accomplished. On the question if DES facilitates the decision-making process 79% of totally 3 8 answered to a very large or a large extent. Regarding the question if DES is a useful tool for measuring the availability of equipment for example system verification 73% of 33 responded to a very large or a large extent. A majority o f the respondents genuinely see an advantage with the use of simulation, which i s an important result from the study. The cost reduction aspect of the productio n is also an advantage of DES. On the question eight answered to a very large ex tent and 23 to a large extent of total 39 replies. The question demonstrates tha t the results of a simulation model are indeed used in the real world. Finally, in the question of DES is used for staffing it is indicated that it is not so co mmonly used as for other functions asked for. The staffing issue requires good k nowledge about time measurement of manual labor. The option, however, to include manual work in a simulation model is in many programs extensive and must be a v aluable option to evaluate work intensive parts of production lines and their im provement. To conclude, it could be mentioned that DES is a tool with potential. The use is increasing and 12 of 80 companies investigated in Sweden 2001 are using it, an increase compared to previous stud-ies. Of those 12 companies, four are using t he tool to a large extent. The main advantage according to the survey beside the visualization part is that the knowledge about a system is investigated and doc umented.
文摘The Riyadh metro project is one of the current megaprojects that aim to improve the transit systems in Saudi Arabia.It consists of several metro lines with a total length of 176 km and 85 stations.The viaducts are considered as one of the main construction elements in the metro lines.Four methods for viaducts construction have been used in the Riyadh metro project:precast beam,full span launching method,cast on-site,and segment method(precast segment method and BCM(balanced cantilever method)).The viaducts work consumes a large portion of a project’s time and cost.Furthermore,the competitive nature of the construction industry increases the need to improve the efficiency of construction performance.Accordingly,this paper takes the initial steps toward increasing the efficiency of viaduct construction methods through simulation.Simulation of construction processes provides a systematic tool that can be used for determining the resources,time,and cost of these processes.The simulation processes should focus on the main activities affecting this element’s execution for viaducts construction,such as segment storage,handling,transporting,and installation.This study highlights the viaducts construction methods and develops general discrete-event simulation models for the most commonly used viaducts construction methods in the Riyadh metro using AnyLogic simulation software.The simulation models visualize and capture the interaction between the different activities and resources in a viaduct construction.Consequently,the construction drawbacks can be identified.Furthermore,the simulation model can be manipulated by adding assumptions to develop more efficient construction methods in terms of time and cost in such projects.
基金the Key Grant Project of Ministry of Education of the People’s Republic of China through Project,China(No.113027A)the Fundamental Research Funds for the Central Universities,China
文摘The goal of this paper is to provide an approach to investigate the variation of fiber quantity in a certain cross-section of the drafting zone. This model with discrete-event simulation( DES)method was presented to simulate the dynamic drafting process. This model described the behavior of individual fibers,which was divided into four phases and simulated by corresponding modules. Three sets of processing conditions in industry were simulated and demonstrated the applications of this model. The comparison between experiments and simulation results could also validate this model. This model could be used to simulate various drafting process with appropriate drafting settings.
文摘Object-oriented world-view provides a natural and powerful paradignl for expressing system elements and their dynamic behaviour for discrete-event simulation. Simulation gives the critical ability to study the dynamic behaviour of the models that are defined with object-voriented means. This paper first examines the ways of applying the object-oriented world-view to three major discrete simulation modelling approaches, then considers the process and merits of object-oriented simulation modelling.
基金Opening Foundation of Key Laboratory of Explosive Energy Utilization and Control,Anhui Province(BP20240104)Graduate Innovation Program of China University of Mining and Technology(2024WLJCRCZL049)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX24_2701)。
文摘Because of the challenge of compounding lightweight,high-strength Ti/Al alloys due to their considerable disparity in properties,Al 6063 as intermediate layer was proposed to fabricate TC4/Al 6063/Al 7075 three-layer composite plate by explosive welding.The microscopic properties of each bonding interface were elucidated through field emission scanning electron microscope and electron backscattered diffraction(EBSD).A methodology combining finite element method-smoothed particle hydrodynamics(FEM-SPH)and molecular dynamics(MD)was proposed for the analysis of the forming and evolution characteristics of explosive welding interfaces at multi-scale.The results demonstrate that the bonding interface morphologies of TC4/Al 6063 and Al 6063/Al 7075 exhibit a flat and wavy configuration,without discernible defects or cracks.The phenomenon of grain refinement is observed in the vicinity of the two bonding interfaces.Furthermore,the degree of plastic deformation of TC4 and Al 7075 is more pronounced than that of Al 6063 in the intermediate layer.The interface morphology characteristics obtained by FEM-SPH simulation exhibit a high degree of similarity to the experimental results.MD simulations reveal that the diffusion of interfacial elements predominantly occurs during the unloading phase,and the simulated thickness of interfacial diffusion aligns well with experimental outcomes.The introduction of intermediate layer in the explosive welding process can effectively produce high-quality titanium/aluminum alloy composite plates.Furthermore,this approach offers a multi-scale simulation strategy for the study of explosive welding bonding interfaces.
基金supported by the Research Funding of Hangzhou International Innovation Institute of Beihang Uni-versity,China(No.2024KQ130)the National Natural Science Foundation of China(Nos.52073010 and 52373259).
文摘Recent progress in microwave absorption materials stimulates the extensive exploration of rare earth oxide materials.Herein,we report the synthesis of a hollow sphere-based carbon material compounded with rare earth oxides.Hollow N-doped carbon nano-spheres loaded ceria composites(H-NC@CeO_(2))were designed and prepared by the template method,combined with in-situ coating,pyrolysis and chemical etching.By controlling the loading content of H-NC@CeO_(2)and adjusting the impedance matching of the material,the H-NC@CeO_(2)/PS(polystyrene)composite exhibited a minimum reflection loss(RL)of-50.8 dB and an effective absorption band-width(EAB)of 4.64 GHz at a filler ratio of 20wt%and a thickness of 2 mm.In accordance with measured electromagnetic parameters,simulations using the high frequency structure simulator(HFSS)software were conducted to investigate the impact of the honeycomb structure on the electromagnetic wave performance of H-NC@CeO_(2)/PS.By calculating the surface electric field and the material’s bulk loss density,the mechanism of electromagnetic loss for the honeycomb structure was elaborated.A method for structural design and man-ufacturing of broadband absorbing devices was proposed and a broadband absorber with an EAB of 11.9 GHz was prepared.This study presents an innovative approach to designing advanced electromagnetic(EM)wave absorbing materials with broad absorption band-widths.
基金the National Natural Science Foundation of China(No.52205468)China Postdoctoral Science Foundation(No.2022M710061 and No.2023T160277)Natural Science Foundation of Jiangsu Province(No.BK20210755)。
文摘Large size titanium alloy parts are widely used in aerospace.However,they are difficult to manufacture using mechanical cutting technology because of severe tool wear.Electrochemical jet machining is a promising technology to achieve high efficiency,because it has high machining flexibility and no machining tool wear.However,reports on the macro electrochemical jet machining of large size titanium alloy parts are very scarce,because it is difficult to achieve effective constraint of the flow field in macro electrochemical jet machining.In addition,titanium alloy is very sensitive to fluctuation of the flow field,and a turbulent flow field would lead to serious stray corrosion.This paper reports a series of investigations of the electrochemical jet machining of titanium alloy parts.Based on the flow analysis and experiments,the machining flow field was effectively constrained.TB6 titanium alloy part with a perimeter of one meter was machined.The machined surface was smooth with no obvious machining defects.The machining process was particularly stable with no obvious spark discharge.The research provides a reference for the application of electrochemical jet machining technology to achieve large allowance material removal in the machining of large titanium alloy parts.
基金Funded by the Research Funds of China University of Mining and Technology(No.102523215)。
文摘The pre-wetting of aggregate surface is a means to improve the interface performance of SBS modified asphalt and aggregate.The effect of pre-wetting technology on the interaction between SBS modified asphalt and aggregate was analyzed by molecular dynamics simulation.The diffusion coefficient and concentration distribution of SBS modified asphalt on aggregate surface are included.The simulation results show that the diffusion coefficient of the aggregate surface of SBS modified asphalt is increased by 47.6%and 70.5%respectively after 110#asphalt and 130#asphalt are pre-wetted.The concentration distribution of SBS modified asphalt on the aggregate surface after pre-wetting is more uniform.According to the results of interface energy calculation,the interface energy of SBS modified bitumen and aggregate can be increased by about 5%after pre-wetting.According to the results of molecular dynamics simulation,the pre-wetting technology can effectively improve the interface workability of SBS modified bitumen and aggregate,so as to improve the interface performance.
基金supported by the National Natural Science Foundation of China(Grant No.U21B2062)supported by the Key Laboratory for Carbonate Reservoirs of China National Petroleum Corporation。
文摘Burial dissolution is a critical diagenetic process influencing ultra-deep carbonate reservoir development and preservation.Artificial carbonate samples with different internal structures were prepared,and high-temperature and highpressure dissolution kinetic simulations were conducted.The results demonstrate that the intensity of burial dissolution is controlled by temperature and pressure,while tectonic-fluid activity influences the development pattern of burial dissolution,ultimately determining the direction of its differential modification.Extensive burial dissolution is likely to occur primarily at relatively shallow depths,significantly influencing reservoir formation,preservation,modification,and adjustment.The development of faults facilitates the maintenance of the intensity of burial dissolution.The maximum intensity of burial dissolution occurs at the tips and overlap zones of faults and intersections of multiple faults.The larger the scale of the faults,the more conducive it is to the development of burial dissolution.Burial dissolution fosters the formation of fault networks characterized by enhanced reservoir capacity and permeability.Burial dissolution controlled by episodic tectonic-fluid activity is a plausible explanation for forming the Tarim Basin's ultra-deep fault-controlled“stringbead-like”reservoirs.
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2021B0301030001)the National Key Research and Development Program of China(Grant No.2021YFB3802300)the Foundation of National Key Laboratory of Shock Wave and Detonation Physics(Grant No.JCKYS2022212004)。
文摘The graded density impactor(GDI)dynamic loading technique is crucial for acquiring the dynamic physical property parameters of materials used in weapons.The accuracy and timeliness of GDI structural design are key to achieving controllable stress-strain rate loading.In this study,we have,for the first time,combined one-dimensional fluid computational software with machine learning methods.We first elucidated the mechanisms by which GDI structures control stress and strain rates.Subsequently,we constructed a machine learning model to create a structure-property response surface.The results show that altering the loading velocity and interlayer thickness has a pronounced regulatory effect on stress and strain rates.In contrast,the impedance distribution index and target thickness have less significant effects on stress regulation,although there is a matching relationship between target thickness and interlayer thickness.Compared with traditional design methods,the machine learning approach offers a10^(4)—10^(5)times increase in efficiency and the potential to achieve a global optimum,holding promise for guiding the design of GDI.
基金Scientific Research Fund of Institute of Engineering Mechanics,China Earthquake Administration under Grant No.2023C01National Natural Science Foundation of China under Grant No.52478570Distinguished Young Scholars Program of the Natural Science Foundation of Heilongjiang Province,China under Grant No.JQ2024E002。
文摘The 2025 M_(w)7.7 Myanmar earthquake highlighted the challenge of near-fault seismic intensity field reconstruction due to sparse seismic networks.To address this limitation,a framework was proposed integrating seismic wave simulation with a data-constrained finite-fault rupture model.The constraint is implemented by identifying the optimal ground motion models(GMMs)through a scoring system that selects the best-fit GMMs to mid-and far-field China Earthquake Networks Center(CENC)seismic network data;and applying the optimal GMMs to refine the rupture model parameters for near-fault intensity field simulation.The simulated near-fault seismic intensity field reproduces seismic intensities collected from Myanmar’s sparse seismic network and concentrated in≥Ⅷintensity zones within 50 km of the projected fault plane;and identifies abnormal intensity regions exhibiting≥Ⅹintensity along the Meiktila-Naypyidaw corridor and near Shwebo that are attributed to soft soil amplification effects and near-fault directivity.This framework can also be applied to post-earthquake assessments in other similar regions.
基金National Natural Science Foundation of China(51971103)Key Research and Development Program in Gansu Province(20YF8GA052)。
文摘A suction casting experiment was conducted on Zr_(55)Cu_(30)Al_(10)Ni_(5)(at%)amorphous alloy.Using ProCAST software,numerical simulations were performed to analyze the filling and solidification processes.The velocity field during the filling process and the temperature field during the solidification process of the alloy melt under different process parameters were obtained.Based on the simulation results,a Zr-based amorphous alloy micro-gear was prepared via casting.The results indicate that increasing the suction casting temperature enhances the fluidity of alloy melt but induces unstable flow rate during filling,which is detrimental to complete filling.Zr-based amorphous micro-gears with a module of 0.6 mm,a tooth top diameter of 8 mm,and 10 teeth were prepared through the suction casting.X-ray diffraction and differential scanning calorimetry analyses confirm that the fabricated micro-gear exhibits characteristic amorphous structural features,demonstrating well-defined geometrical contours and satisfactory forming completeness.
