A kind of construction truck model is built in Adams based on multi-body dynamic theory. The rigid and elastic wheels of tire-soil contact models are proposed based on the Bekker pressure model and the Jonasi shear so...A kind of construction truck model is built in Adams based on multi-body dynamic theory. The rigid and elastic wheels of tire-soil contact models are proposed based on the Bekker pressure model and the Jonasi shear soil model, and they are described in the form of S-function to enhance the calculation efficiency and simulation accuracy. Finally, the interaction of truck and soil is simulated by Adams-Maflab co-simulation to study the influence of soft terrain on the ride comfort of vehicles. The co-simulation results reveal that the terrain properties have a great influence on the ride comfort of vehicles as well as driving speed, road roughness and cargo weight. This co-simulation model is convenient for adding the factor of terrain deformation to the analysis of vehicle ride comfort. It can also be used to optimize suspension system parameters especially for off-road vehicles.展开更多
This paper proposes a novel collision post structure designed to improve the crashworthiness of subway cab cars.The structure provides two innovative features:1)a simpler connection between the post and the car roof,w...This paper proposes a novel collision post structure designed to improve the crashworthiness of subway cab cars.The structure provides two innovative features:1)a simpler connection between the post and the car roof,which gives a more reasonable load transfer path to reduce the stress concentration at the joint;and 2)a stiffness induction design that provides an ideal deformation model to protect the safe space of the cab cars.The novel collision post structure was evaluated with finite element analysis,and a prototype cab car was mechanically tested.The results demonstrate that the deformation response was stable and agreed well with the expected ideal mode.The maximum load was 874.17 kN and the responses remained well above the elastic design load of 334 kN as required by the design specification.In addition,there was no significant tearing failure during the whole test process.Therefore,the novel collision post structure proposed has met the requirements specified in new standard to improve the crashworthiness of subway cab cars.Finally,the energy absorption efficiency and light weight design highlights were also summarized and discussed.展开更多
This work proposes a map-based control method to improve a vehicle's lateral stability, and the performance of the proposed method is compared with that of the conventional model-referenced control method. Model-r...This work proposes a map-based control method to improve a vehicle's lateral stability, and the performance of the proposed method is compared with that of the conventional model-referenced control method. Model-referenced control uses the sliding mode method to determine the compensated yaw moment; in contrast, the proposed map-based control uses the compensated yaw moment map acquired by vehicle stability analysis. The vehicle stability region is calculated by a topological method based on the trajectory reversal method. A 2-DOF vehicle model and Pacejka's tire model are used to evaluate the proposed map-based control method. The properties of model-referenced control and map-based control are compared under various road conditions and driving inputs. Model-referenced control uses a control input to satisfy the linear reference model, and it generates unnecessary tire lateral forces that may lead to worse performance than an uncontrolled vehicle with step steering input on a road with a low friction coefficient. However, map-based control determines a compensated yaw moment to maintain the vehicle within the stability region,so the typical responses of vehicle enable to converge rapidly. The simulation results with sine and step steering show that map-based control provides better the tracking responsibility and control performance than model-referenced control.展开更多
基金The National Natural Science Foundation of China(No.50575040)the Natural Science Foundation of Jiangsu Province(No.BK2007112)
文摘A kind of construction truck model is built in Adams based on multi-body dynamic theory. The rigid and elastic wheels of tire-soil contact models are proposed based on the Bekker pressure model and the Jonasi shear soil model, and they are described in the form of S-function to enhance the calculation efficiency and simulation accuracy. Finally, the interaction of truck and soil is simulated by Adams-Maflab co-simulation to study the influence of soft terrain on the ride comfort of vehicles. The co-simulation results reveal that the terrain properties have a great influence on the ride comfort of vehicles as well as driving speed, road roughness and cargo weight. This co-simulation model is convenient for adding the factor of terrain deformation to the analysis of vehicle ride comfort. It can also be used to optimize suspension system parameters especially for off-road vehicles.
基金Project(2016YFB1200505-016)supported by the National Key Research and Development Program of ChinaProject(51675537)supported by the National Natural Science Foundation of ChinaProject(2018zzts161)supported by the Independent Exploration and Innovation Project of Central South University,China。
文摘This paper proposes a novel collision post structure designed to improve the crashworthiness of subway cab cars.The structure provides two innovative features:1)a simpler connection between the post and the car roof,which gives a more reasonable load transfer path to reduce the stress concentration at the joint;and 2)a stiffness induction design that provides an ideal deformation model to protect the safe space of the cab cars.The novel collision post structure was evaluated with finite element analysis,and a prototype cab car was mechanically tested.The results demonstrate that the deformation response was stable and agreed well with the expected ideal mode.The maximum load was 874.17 kN and the responses remained well above the elastic design load of 334 kN as required by the design specification.In addition,there was no significant tearing failure during the whole test process.Therefore,the novel collision post structure proposed has met the requirements specified in new standard to improve the crashworthiness of subway cab cars.Finally,the energy absorption efficiency and light weight design highlights were also summarized and discussed.
基金supported by a grant from Research year of Inje University in 2008(0001200811700)
文摘This work proposes a map-based control method to improve a vehicle's lateral stability, and the performance of the proposed method is compared with that of the conventional model-referenced control method. Model-referenced control uses the sliding mode method to determine the compensated yaw moment; in contrast, the proposed map-based control uses the compensated yaw moment map acquired by vehicle stability analysis. The vehicle stability region is calculated by a topological method based on the trajectory reversal method. A 2-DOF vehicle model and Pacejka's tire model are used to evaluate the proposed map-based control method. The properties of model-referenced control and map-based control are compared under various road conditions and driving inputs. Model-referenced control uses a control input to satisfy the linear reference model, and it generates unnecessary tire lateral forces that may lead to worse performance than an uncontrolled vehicle with step steering input on a road with a low friction coefficient. However, map-based control determines a compensated yaw moment to maintain the vehicle within the stability region,so the typical responses of vehicle enable to converge rapidly. The simulation results with sine and step steering show that map-based control provides better the tracking responsibility and control performance than model-referenced control.
