Study On Safty Performance Of The Bumper On The Front End Of A Car

This paper is carried out combining one vehicle development project which is launched by FAW Research and Development Center.In this paper,A model is constructed on the computer that defines the geometry and physical properties of the components to be tested as well as the test of the real car. In the CAE ,With the loading in ECER42 the bumper beam behaves in an elastic manner with no permanent damage.It proves that the simulation will has enough validity in the future research of this paper.The changes of characteristics of material and geometry caused by stamping all influence the precision of CAE. In this thesis it also shows that a typical structure and a simplified car model were built using one step forming and mapping method based on VPG and KMAS software,thus enabling us to define it Fast Fine Simulation method (FFS); likewise, the pure static bend test and the front impact test complied with ECER42 were respectively completed. Compared with traditional crash analysis, at least 8% accuracy was achieved for the case of this study. The methodology presented in this paper can provide more accurate information for constraint system optimization based on a good comprehension of the impulses, of the peak and of the process of acceleration, as well as of the deformation and of the energy management. More accurate input can also reduce the works of next process within a crash research. FFS result shows better consistency with the result of the test and, at the same time, it can reduce a lot of calculation cycle.The structural design of current vehicle front units has to account for an increasing number of constraints: improvement of real world performance in safety for occupants and others road users, perform in the various ratings and meet future regulations.Therefore the structural car design is the result of a compromise between pedestrian protection, car to car compatibility and self-protection.Some of these constraints lead to solutions which are in opposition and in general to unsatisfactory compromises. It is suggest to develop a more comprehensive approach in order to better take into account each safety requirement. This paper describes the different relevant factors for each safety and requirement, proposes compromise among them in terms of structural aspects. It will also show that it is often difficult to find an answer which satisfies all these aspects. In this paper the experience over the large numbers of tests and CAE , associated with a real awareness for safety, is suggesting to approach front-unit design progress from a global viewpoint.