In order to investigate the permanent deformation behavior of asphalt mixtures from discontinuity, the virtual rutting test of asphalt mixtures is developed by the discrete element method （DEM）. A digital specimen g...In order to investigate the permanent deformation behavior of asphalt mixtures from discontinuity, the virtual rutting test of asphalt mixtures is developed by the discrete element method （DEM）. A digital specimen generation procedure considering aggregate gradation and irregular shape is developed based on the probability theory and the Monte Carlo method. The virtual rutting test is then conducted based on the generated digital specimen. In addition, on the basis of the time-temperature superposition （TTS） principle, a calculation method is used to reduce the computation time of the virtual rutting test. The simulation results are compared with the laboratory measurements. The results show that the calculation method based on the TFS principle in the discrete element （DE） viscoelastic model can significantly reduce the computation time. The deformation law of asphalt mixtures in the virtual rutting test is similar to the laboratory measurements, and the deformation and the dynamic stability of the virtual rutting test are slightly greater than the laboratory measurements. The two-dimensional virtual rutting test can predict the permanent deformation performance of asphalt mixtures.展开更多
This paper explores how to build a full truck vehicle in ADAMS environment and do a series of simulations to test the model’s stability. Then a comparison is made between the simulation result and the actual experime...This paper explores how to build a full truck vehicle in ADAMS environment and do a series of simulations to test the model’s stability. Then a comparison is made between the simulation result and the actual experimental result, proving the model’s correctness.展开更多
Traffic jam in large signalized road network presents a complex nature.In order to reveal the jam characteristics,two indexes,SVS(speed of virtual signal) and VOS(velocity of spillover),were proposed respectively.SVS ...Traffic jam in large signalized road network presents a complex nature.In order to reveal the jam characteristics,two indexes,SVS(speed of virtual signal) and VOS(velocity of spillover),were proposed respectively.SVS described the propagation of queue within a link while VOS reflected the spillover velocity of vehicle queue.Based on the two indexes,network jam simulation was carried out on a regular signalized road network.The simulation results show that:1) The propagation of traffic congestion on a signalized road network can be classified into two stages:virtual split driven stage and flow rate driven stage.The former stage is characterized by decreasing virtual split while the latter only depends on flow rate; 2) The jam propagation rate and direction are dependent on traffic demand distribution and other network parameters.The direction with higher demand gets more chance to be jammed.Our findings can serve as the basis of the prevention of the formation and propagation of network traffic jam.展开更多
This paper developed 3D product models of motorcycle and engine by UGNX as well as virtual prototyping by ADAMS program with road roughness generated by MATLAB. Under the straight-line running condition, the dynamic r...This paper developed 3D product models of motorcycle and engine by UGNX as well as virtual prototyping by ADAMS program with road roughness generated by MATLAB. Under the straight-line running condition, the dynamic responses of motorcycle multibody system to both road and engine excitations were compared with those to only road excitation in terms of vertical acceleration response, amplitude frequency response and power spectral density. The comparisons of simulation data showed that the response due to flat road excitation was around 20 Hz, while that to the combined excitations was in a wide frequency band, of which the major components focused on 10 Hz, 15 Hz, 35 Hz ,70 Hz, 100 Hz and even higher frequencies, reflecting the characteristics of engine excitation based on its unbalanced inertia force and torque. It is concluded that the high fidelity virtual prototyping can simulate the dynamics of motorcycle product well in investigating the vibration and ride comfort performance.展开更多
It is more positive and instructive attempt for the Virtual Reality technology to be used in the education of automobile repairments. And it give us a new method and direction to professional education reform.
This paper reviews virtual reality interface, application and design concept in relation with our experience in implementing a virtual bicycling environment application of the University of Indonesia Green Eco-campus....This paper reviews virtual reality interface, application and design concept in relation with our experience in implementing a virtual bicycling environment application of the University of Indonesia Green Eco-campus. The implementation of the Virtual Reality VR used 3D-Games Studio with Lite-C software. The authors also experiment with the use of a VR device, i.e. 3D E-Dimensional wireless goggle to improve the feel of presence for the user of our application. The authors created the original elements of UI campus environment, such as, buildings, trees, campus buses, cars, and bike tracks, as well as obstacle in the pathways into 3D virtual shape that resembles the real UI campus environment. The bicycle movement, camera perceptions, and object collision handling have also been implemented. Our application is subsequently tested by the users in terms of the general object condition, user＇s respond to the virtual reality environment and the future development. Some result of implementing the same environment using Alice has also been shown.展开更多
基金The National Natural Science Foundation of China(No.51108081)
文摘In order to investigate the permanent deformation behavior of asphalt mixtures from discontinuity, the virtual rutting test of asphalt mixtures is developed by the discrete element method （DEM）. A digital specimen generation procedure considering aggregate gradation and irregular shape is developed based on the probability theory and the Monte Carlo method. The virtual rutting test is then conducted based on the generated digital specimen. In addition, on the basis of the time-temperature superposition （TTS） principle, a calculation method is used to reduce the computation time of the virtual rutting test. The simulation results are compared with the laboratory measurements. The results show that the calculation method based on the TFS principle in the discrete element （DE） viscoelastic model can significantly reduce the computation time. The deformation law of asphalt mixtures in the virtual rutting test is similar to the laboratory measurements, and the deformation and the dynamic stability of the virtual rutting test are slightly greater than the laboratory measurements. The two-dimensional virtual rutting test can predict the permanent deformation performance of asphalt mixtures.
文摘This paper explores how to build a full truck vehicle in ADAMS environment and do a series of simulations to test the model’s stability. Then a comparison is made between the simulation result and the actual experimental result, proving the model’s correctness.
基金Project(2012CB725402)supported by the State Key Development Program for Basic Research of ChinaProject(2012MS21175)supported by the National Science Foundation for Post-doctoral Scientists of ChinaProject(Bsh1202056)supported by the Excellent Postdoctoral Science Foundation of Zhejiang Province,China
文摘Traffic jam in large signalized road network presents a complex nature.In order to reveal the jam characteristics,two indexes,SVS(speed of virtual signal) and VOS(velocity of spillover),were proposed respectively.SVS described the propagation of queue within a link while VOS reflected the spillover velocity of vehicle queue.Based on the two indexes,network jam simulation was carried out on a regular signalized road network.The simulation results show that:1) The propagation of traffic congestion on a signalized road network can be classified into two stages:virtual split driven stage and flow rate driven stage.The former stage is characterized by decreasing virtual split while the latter only depends on flow rate; 2) The jam propagation rate and direction are dependent on traffic demand distribution and other network parameters.The direction with higher demand gets more chance to be jammed.Our findings can serve as the basis of the prevention of the formation and propagation of network traffic jam.
基金Supported by National Natural Science Foundation of China (No. 51176138)
文摘This paper developed 3D product models of motorcycle and engine by UGNX as well as virtual prototyping by ADAMS program with road roughness generated by MATLAB. Under the straight-line running condition, the dynamic responses of motorcycle multibody system to both road and engine excitations were compared with those to only road excitation in terms of vertical acceleration response, amplitude frequency response and power spectral density. The comparisons of simulation data showed that the response due to flat road excitation was around 20 Hz, while that to the combined excitations was in a wide frequency band, of which the major components focused on 10 Hz, 15 Hz, 35 Hz ,70 Hz, 100 Hz and even higher frequencies, reflecting the characteristics of engine excitation based on its unbalanced inertia force and torque. It is concluded that the high fidelity virtual prototyping can simulate the dynamics of motorcycle product well in investigating the vibration and ride comfort performance.
文摘It is more positive and instructive attempt for the Virtual Reality technology to be used in the education of automobile repairments. And it give us a new method and direction to professional education reform.
文摘This paper reviews virtual reality interface, application and design concept in relation with our experience in implementing a virtual bicycling environment application of the University of Indonesia Green Eco-campus. The implementation of the Virtual Reality VR used 3D-Games Studio with Lite-C software. The authors also experiment with the use of a VR device, i.e. 3D E-Dimensional wireless goggle to improve the feel of presence for the user of our application. The authors created the original elements of UI campus environment, such as, buildings, trees, campus buses, cars, and bike tracks, as well as obstacle in the pathways into 3D virtual shape that resembles the real UI campus environment. The bicycle movement, camera perceptions, and object collision handling have also been implemented. Our application is subsequently tested by the users in terms of the general object condition, user＇s respond to the virtual reality environment and the future development. Some result of implementing the same environment using Alice has also been shown.
