Simulation And Analysis Of Car Frontal Small Offset Crash Based On FEM

Vehicle frontal crash occupies a high proportion in the ve hicle accident, which leads to huge economic losses and casualties every year. Small overlap crash is a high incidence of accident form in various overlap frontal crashes, and its mortality and injury rate is very high. Most automaker only meet the requirement of 40% overlap and 100% overlap crash, but they haven't take the small overlap crash seriously.Currently, only the North America IIHS has car against wall with 25% overlap crash test. The test is not compulsive and is only as an additional test. However, the actual traffic accidents is not the same as the test in the IIHS that the car impact the stationary wall. Instead, the driving two cars crash with a small angle and overlap, that is, small offset crash. A severe challenge about car to car small offset crash is how to let two cars move at the same time and coordinate their velocity and position. The finite element method can truly simulate that kind of accident type, especially the small overlap crash, reducing the cost and difficulty and shortening cycle.In this paper, after reading a large number of literature and consulted a large number of small overlap crash test, I introduced the current research at home and abroad and dynamic progress. I built three kind of crash model to simulate, compare and analyze.1.25% overlap crash with 15°angle car against car FEM model of collision, which is used to test the anti-crash and safety quality; 2. Car against wall crash with a 40% overlap FEM model of collision, which is used to simulate whether the 40% overlap crash can also test the safety of the car in small offset crash.3. Car against wall crash with a 25% overlap FEM model of collision, which is used to compare with the additional car against wall with 25% overlap crash in the IIHS.The comparison among three different crash test indicated that small offset crash is a very severe kind of accident form and is the weakness of car's anti-crash quality. Because there is a small angle between the two car and the overlap is very small., the bumpers slip away from each other and let the front longitudinal, which makes the energy absorbing structure gets rid of the crash and does works. It means the energy absorbing area crosswise stiffness of the car model is not bigger enough and crosswise transmission path is not strong enough. Comparing to the 40%, the acceleration of the small offset crash and 25% overlap crash is smaller. However, the direction of the inertia that the driver's head suffers from is toward A pillar and the restraint system including the airbag and belt can't protect the human properly from injury. The existing compulsory crash test can't evaluate the anti-crash and safety quality. The study contribute to the change of the improvement of the existing criteria and increasing people's awareness to the small offset crash, and provide a reference for the automaker to carry out the small offset crash simulation.