The Inter-collision Test Device And Research On Its Absorption Characteristic

The sled test is used to replace the real vehicle collision safety test.It has the advantages of low cost,good repeatability and high accuracy.This inter-collision sled is a new generation device based on the traditional collision system.The space occupied of the system is greatly reduced by using elastic ropes as the driving force.It transforms the collision force from traditional external force between sled and fixed barrier to internal force between test sled and counter-weight sled by head-on collision.The cost of the foundation is reduced without a fixed barrier.The energy absorption device is the key to reproduce the acceleration waveform.The characteristics of the energy-absorbing of the thin-walled pipes in each working condition are analyzed.And then it proposes a method of energy-absorbing by lateral flattening.In order to reproduce the national standard GB15083-2006,a finite element model?FEM?of the energy absorption device was firstly established.By means of quasi-static tensile test and adjusting the contact friction coefficient between the energy absorption tubes and the compression block,the objective function extracted from two comparison displacement-force curves was determined by using a least square method.The simulation results show that the displacement-force curve and deformation mode of the simulation are in good agreement with the experiment when the friction coefficient is 0.177.On this basis,a complete FEM of the inter-collision sled is established and verified by real sled test.Dynamic response characteristics are analyzed while two or four energy-absorbing tubes are effective,the influence of tubes and compression blocks'geometry are also studied.Finally,it summarizes the methods and steps of the waveform reproduction.The number,length,wall thickness and other parameters of each regulation are listed.According to G₁-G₂ design procedure and principle of equivalent dual-trapezia wave?EDTW?,a fitting method of EDTW is proposed.Based on a verified FEM of vehicle frontal crash,a contrast research of occupant injury is carried out under the function of EDTW,reproduced wave and original acceleration wave.The results show that the reproduced waveform can partly replace real vehicle acceleration for occupant injury research.