In actual line operation,the critical velocity is one of the key physical quantities of rail design owing to its great infuence on the riding comfort and safety of vehicles due to the wheel-rail contact loss caused by...In actual line operation,the critical velocity is one of the key physical quantities of rail design owing to its great infuence on the riding comfort and safety of vehicles due to the wheel-rail contact loss caused by the abrupt change of rail foundation rigidity,rail wear,or abruptness irregularities on rail.In this study,the short floating slab track(SFST)structure is regarded as a double-layer system.The Euler beam and the rigid body model are adopted for the rail and the floating slab,respectively.and the dispersion equation and the theoretical critical velocity of the rail structure under ideal conditions are deduced.Besides,this st udy considers the implementation of the SFST in the vehicle-structure coupling system.The alterable element method is introduced for accurately simulating the change of the whee-rail contact state and coding a vehicle-structure dynamic analysis program(VSDAP)to calculate the critical velocity of rail structures from the dynamic response of vehicles and rail structures.The principle of its design at the beginning of the design is given on the basis of the theoretical value of the critical velocity and the simulation of the dynamic response,which can provide reference for practical engineering design.展开更多
A new approach for treating the mesh with Lagrangian scheme of finite volume method is presented. It has been proved that classical Lagrangian method is difficult to cope with large deformation in tracking material pa...A new approach for treating the mesh with Lagrangian scheme of finite volume method is presented. It has been proved that classical Lagrangian method is difficult to cope with large deformation in tracking material particles due to severe distortion of cells, and the changing connectivity of the mesh seems especially attractive for solving such issues. The mesh with large deformation based on computational geometry is optimized by using new method. This paper develops a processing system for arbitrary polygonal unstructured grid,the intelligent variable grid neighborhood technologies is utilized to improve the quality of mesh in calculation process, and arbitrary polygonal mesh is used in the Lagrangian finite volume scheme. The performance of the new method is demonstrated through series of numerical examples, and the simulation capability is efficiently presented in coping with the systems with large deformations.展开更多
基金the National Natural Science Founda-tion of China(No.51675324)the Shanghai Founda-tion for University Key Teacher(No,ZZGCD15039)New Energy Vehicle Vibration and Noise Test and Control Professional Technical Service Platform(No.18DZ2295900)。
文摘In actual line operation,the critical velocity is one of the key physical quantities of rail design owing to its great infuence on the riding comfort and safety of vehicles due to the wheel-rail contact loss caused by the abrupt change of rail foundation rigidity,rail wear,or abruptness irregularities on rail.In this study,the short floating slab track(SFST)structure is regarded as a double-layer system.The Euler beam and the rigid body model are adopted for the rail and the floating slab,respectively.and the dispersion equation and the theoretical critical velocity of the rail structure under ideal conditions are deduced.Besides,this st udy considers the implementation of the SFST in the vehicle-structure coupling system.The alterable element method is introduced for accurately simulating the change of the whee-rail contact state and coding a vehicle-structure dynamic analysis program(VSDAP)to calculate the critical velocity of rail structures from the dynamic response of vehicles and rail structures.The principle of its design at the beginning of the design is given on the basis of the theoretical value of the critical velocity and the simulation of the dynamic response,which can provide reference for practical engineering design.
基金supported in part by the National Natural Science Foundation of China under Grant 11372051,Grant 11475029part by the Fund of the China Academy of Engineering Physics under Grant 20150202045
文摘A new approach for treating the mesh with Lagrangian scheme of finite volume method is presented. It has been proved that classical Lagrangian method is difficult to cope with large deformation in tracking material particles due to severe distortion of cells, and the changing connectivity of the mesh seems especially attractive for solving such issues. The mesh with large deformation based on computational geometry is optimized by using new method. This paper develops a processing system for arbitrary polygonal unstructured grid,the intelligent variable grid neighborhood technologies is utilized to improve the quality of mesh in calculation process, and arbitrary polygonal mesh is used in the Lagrangian finite volume scheme. The performance of the new method is demonstrated through series of numerical examples, and the simulation capability is efficiently presented in coping with the systems with large deformations.
