Study On Design Procedures Of Frontal Crash Worthiness For Passenger Car

At present the automobile industry faces three important subjects–"Safety, Environmental Protection, Energy Saving". Automobile safety includes active safety and passive safety. Active safety can automatically avoid vehicle from accident and reduce accident happening probability, while passive safety also reduces occupants'injuring and the property damaging by enhancing crashworthiness and optimizing occupant restraint system. After promulgating GB11551-2003 and carrying out CNCAP, the safety design of passenger car becomes the focus for all automobile manufactories. It's very important to solve the vehicle body crash worthiness in the development period for them.Frontal crash is the major crash form in real traffic accident, and the frontal crash worthiness is the essential design target for vehicle passivity. When appearing a fault design in the tradition design procedures, it's difficult to modify the structure and will delay the development period, sometimes. For avoiding the problem which is mentioned, this paper submit a design method which designing body structure from concept design to multiple targets optimization design. It will realize the performance control to the vehicle body structure. The content and innovation in my paper are as follows:1. Applying the traffic accident investigation to design the passenger car body structure for crash worthiness. Controlling the performance at the production definition phases for the first time.2. Applying MADYMO to design the passenger car body structure for crash worthiness in concept phases. Extracting section parameter of the front structure, and realizing energy management.3. Realizing multi-targets and multi-parameters optimization control according to designing the front structure (bumper beam, crash box and front beam) for different frontal crash forms(low speed, high speed-40%ODB and 100%FRB).4. Anatomizing the phenomena which the bumper beam is broken during 40%ODB crash test. Putting forward the interrelated method to solve and validating it by the vehicle crash test.5. Applying the energy density method to analyses the performance of the front structure which is serious deformable during first 20~30ms in the 100% rigid wall crash. By this method, we initialize the speed of airbag deploys, and we will get the speed of airbag doesn't deploy. That will efficiently reduce the phenomena which the airbag deploys in the low speed.6. expounding the normal method for front passenger restraint system performance control.7. A large amount of simulations was carried out by using Hyper-Works, VPG, Ls-Dyna and Madymo. And evaluating and contrasting the analyses result of the frontal crash worthness.This thesis founds a method which designs the passenger car body structure, from real traffic accident investigation to concept design, and to optimize the front structure(bumper beam, crash box and front beam) with different frontal crash form, and to matching the passenger restraint system. This thesis will become a special reference to most OEMs in China.