Study On The Sled Crash Method For Offset Deformable Barrier Crash Test By Using Restraint System Simulation Analysis

Road traffic accidents have become a worldwide problem, which seriouslythreaten the social-economic development and human lives and property. Our country’saccidents happen frequently. In all types of car crashes, the most common type isfrontal crash accident with the probability up to40%. In a variety of frontal crashaccident, the traffic accidents simulated by offset deformable impact and the angularimpact probability accounted for59%, and the offset crash causes more injuries.Therefore, it is critical to improve the car safety performance in the offset crash inorder to reduce the injuries. Especially in2012, the C-NCAP rule changed the speed ofoffset deformable crash tests from56km/h to64km/h. It has become an important andurgent task as how to further improve the car safety performance in40%offsetdeformable crash.There are two ways to study automobile collision safety. First, test, and it includesvehicle test and sled test, which are used to evaluate car safety. Second, it is CAEcomputer simulation analysis. Currently, the automobile collision safety is studied bythe combination of test method and computer simulation. Because of vehicle test costmuch and time-consuming, so the sled test is used to simulate the vehicle test. But dueto the single degree of freedom movement, it is hard to simulate the passengers’ injurycaused by vehicle’s rotation, so that it is not accurate for the traditional sled test tosimulate40%vehicle test.In order to solve the above problems, this paper presents a new method for thesled test to replace the64km/h40%vehicle offset crash test based on the driver’s sidemodel of the restraint system. The method is to give the sled an initial fixed deflectionangle and a optimized acceleration waveform to provide more accurate collision pulsefor the offset sled crash test.Firstly, based on constant acceleration circle rule, this paper simplifies the offsetcrash and analyzes kinetic model. The rule is used to calculate the acceleration vectorin vehicle body by combining with the vehicle acceleration test. The initial fixeddeflection angle of the sled and collision acceleration wave are determined by the rule.Secondly, a restraint system model is established by using software MADYMO. Themodel is optimized to confirm the validity of the model. Finally, the64km40%offsetsled crash simulation analysis is done. The results show that the injury curves in the sled test and the vehicle test are close to each other in the rate of80%, so the newmethod is confirmed viable.The proposed64km/h40%offset collision sled method and the solve way willimprove a reliable test method for the further restraint system study. Therefore, thenumber of vehicle crash tests and the development timing are reduced through themethod. It has a higher practical value.