Simulation Study On Crash Of Urban Railway Vehicles And Front Structure Optimization

Urban Railway Transportation has become one of the most important transport tool in industrialized countries for its flexiblity, low costing and incredible capability of transporting passenger .The more important role urban rail Transportation plays in public transport system, the more attention should be paid on security. In this paper, collision performance reasearch works of urban rail vehicle mainly rely on deformation, contact force, acceleration and energy. In the process of collision, a reasonable deformation of the front vehicles body can supply sufficient security space for the passengers, and a vehicles body with good crashworthiness can absorbe most of the collision energy. On the basis of these theories, the vehicles body structure of Shanghai subway Line 6, 8 was tested and verified about designation rationality with FE collision software PAM-CRASH.The vehicle body structure crashworthiness lie on energy-absorption ability of the front vehicle body.Therefore, derermining the vehicle body energy-absorption structure to diminish weight as low as possible and to guarantee the passengers living space. In this paper, with the bridge combination of iSIGHT optimization software and PAM-CRASH, we aim to find optimization algorithm to cut down the vehicle body structure weight on the basis that the energy-absorbing structure could absorb certaina amount energy.In addition, a genetic optimization algorithm has been developed to optimize the vehicle body front truss structure to ensure the validity of the energy-absorbing capability. In this article we emphasize on the safety of the lorry in collision process equipped with truss structure which is a common mode of engineering structures. we extract the sub-structure of lorry body for optimization, compile the Hypermesh model output file, form the APDL language based on ANSYS added with statement variables, constraints and definition of the output, and carry on the iterative optimization using the genetic algorithm calculation model in the ANSYS program. Utimately, the objective function approches an approximate optimal solution as the iterative time increase, and than verity the optimized model with PAM-CRASH, Finally, feasibility of genetic algorithm used in structure of engineering could be verified.