| Automobile, act as the modern vehicle, brings a great deal of convenience to our daily life, at the same time, it also exposes us to some danger. Every year the number of victims in car accidents precedes that of local war of the world. Traffic accident not only causes enormous economic losing, but also many social problems, such as the increasing of disabled people and family misfortune. From this point of view, traffic accident has become one of the most severe social effects. Today, strictly crash safety statutes were established in main Automobile industry allover the world and Automobile products must satisfy with the statutes. The first whole car crash safety statute of our county was compiled in Sep.1989, in which 38 compulsory requirements about car crash safety were proposed. January 1, 2000, CMVDR294 was brought into effect. It requires the automobiles cataloged after Oct.1999 must satisfy the requirement of the statute, and those could not achieve must be structural improved before Jul.1, 2002 or the manufacture would be halted. So the research about car safety, the improvement of vehicle crashworthiness and the reduction of dead ratio of car accident has become the most important problem of our automobile industry and also the urgent task of car manufactures.In this article, dynamic explicit finite element analysis method was employed to increase the crashworthiness of SC6350 (Chang'an Star) and develop new product. The research was carried out combining with real car tests. The computer aided simulation technique and design methods of vehicle frontal impact was also studied systematically. Further more, the author applied this technique to undertake the development of the new prototype car SC6370 (named Chang'an Snow Tiger). The result revealed that the frontal crash performance got a wonderful melioration. Fist, using SC6350 for an example, the writer analyzed the critical elements that affect the simulation of passenger car frontal impact, and found the feasible way to deal with the conflict between calculation efficiency and precision. Using this method, the simulation of time history course of full-scale mini-passenger car frontal impact was taken into reality with a spot of elements (less than 22000) and scanty time (16 hours on hpC200 workstation, and 8 hours on P4 PC). At the same time, the precision of the simulation satisfied the requirement of engineering application. The deformation model and the scalar of deformation at the end of the simulation reach a perfect agreement withreal car test. The font end components, acting as main energy-absorbing components, showed a perfect agreement with the test, both collapsed in the same pattern. The total plastic deformation of the front longitude member was 195mm (209mm tested), the time courses of the decelerations of fire wall, B pillar and the end of car were coincident with the result of the test. The crashworthiness of front longitude member was also studied in different states, axial loading, non-axial loading and assembly state. The study revealed that if the front end of the longitude member protruded during the deformation, a high summit would appear in the deceleration curve. The more obvious the protrusion was, the higher the peak would be. It also discovered the relationship between the deceleration curve and the front longitude member's deformation, including the mode and the course. Furthermore, an in-depth research about the effect on frontal impact performance caused by typical abduct structure of longitude member was carried out in this article, we deem that if the high peak in the deceleration curve were to be prevented, certain mode and dimension structure should be in control, so that the longitude member could collapse from the front to the end orderly. The research focused on the geometrical fact of abduct slot and abduct hole, such as the position, the dimension and the shape. As a result,a general principle about mini-passenger car crashworthiness design was summarized as bellow: Firstly, the energy absorb...
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