Train driver protection under secondary impact

An EMU train with detailed cabin structural is established based on the finite element method.The secondary impact between train driver and control desk is fully analysed and two measures are proposed to reduce the driver injury severity,such as the multi-objective optimization of the driver seat position and equipping the train with three-point seat belt.Simulation results indicate that the driver seat position has a significant effect on the driver injury severity during a secondary impact.According to the multi-objective optimization,some Pareto solutions are suggested to design the driver seat position.Besides that,it is also indicated although the chest and leg are well protected when the driver wears a two-point seat belt,it increases the head injure during a secondary impact.On the other hand,the three-point seat belt can supply the train driver with an overall protection against the secondary impact.The injury criteria(HIC,VC,TI)of the driver with the three-point seat belt is significantly lower than those of the driver without seat belt.Moreover,according to the simulation analysis,the limited load of the three-point seat belt is suggested about 1.5 kN.

Research on the Infuence of Multiple Parameters on the Responses of a B-type Subway Train

To obtain improved comprehensive crashworthiness criteria for a B-type subway train,the infuence laws of the vehicle design collision weight M and empty stroke D on the train’s collision responses were investigated,and multiobjective optimization and decision-making were performed to minimize TS(total compression displacement along the moving train)and TAMA(the overall mean acceleration along the moving train).Firstly,a one-dimensional train collision dynamics model was established and verifed by comparing with the results of the fnite element model.Secondly,based on the dynamics model,the infuence laws of M and D on the collision responses,such as the energy-absorbing devices’displacements and absorbed energy,vehicles’velocity and acceleration,TS,TAMA and the coupling correlation efect were investigated.Then,surrogate models for TS and TAMA were developed using the optimal Latin hypercube method(OLHD)and response surface method(RSM),and multi-objective optimization was conducted using the particle swarm optimization algorithm method(MPOSO).Finally,the entropy method was used to obtain the weight coefcients for TS and TAMA,and multi-objective decision-making was performed.The results indicate that D and M signifcantly afect the compression displacements and energy absorption of the frst three collision interfaces,but have limited impact on the last three collision interfaces.The velocity versus time curves of vehicle M1 and M2 are shifted and parallel with diferent D.However,the velocity versus time curves of all the vehicles are shifted but gradually divergent with diferent M.The maximum collision instantaneous accelerations of the vehicles are directly determined by M,but are only slightly afected by D.Under the coupling efect,all concerned collision responses are strongly correlated with M;however,the responses are weakly correlated with D except for the compression displacement at the M2-M3 collision interface and the maximum collision instantaneous acceleration of vehicle M2.The comprehensive crashworthiness criteria of the B-type subway train were signifcantly improved after multi-objective optimization and decision-making.The research provides more theoretical and engineering application references for the subway train crashworthiness design.