The Study Of Car Side Impact Simulation Based On VPG

AS a kind of modern transport tool, vehicle is helpful for our social development. But on the other hand, more and more traffic accidents make large damage. In China, from 1980's on, there are about 100 thousand people die for the traffic accidents every year, which makes billions and billions economy lose. China has been in the serious trouble of the traffic accidents. The safety of car has been paid more and more attentions by Chinese government and people, so the study of vehicle-safety is hot point. The vehicle-safety is the base of traffic-safety. Improving the vehicle's quality not only be supposed by public, but also is the object for the whole automotive industry in the world.In this paper, a side impact Finite Element Model of a car is established based on the requirement of GB 20071-2006 regulation,'UNIFORM PROVISIONS CONCERNING THE APPROVAL OF VEHICLES WITH REGARD TO THE PROTECTION OF THE OCCUPANTS IN THE EVENT OF A LATERAL COLLISION'. One car side impact is simulated, and the result is compared with the real crash testing data. Contraposing the testing data, this paper analyzes the simulation data of three objects: vehicle, movable deformable barrier (MDB) and side impact dummy. The contents of this paper include: the skills of application the simulation software Ls-dyna3d, setting the Finite Element Model (FEM) of crash dummy and MDB, building one crash FEM of one car, the research of car side impact simulation technology; and the research of one car's side impact safety. This paper research one car's side impact safety systemically from simulation analyses.The paper sums up skills and key points of building a FEM, how to decide the size of element, how to leave out holes, flanges and sidesteps which won't affect the precision of simulation results, how to assemble the parts using different joint-element, and describes the program of one full size car's simulation from building the model to analyze the result. Concludes drawn from comparative results is: the vehicle, MDB and dummy FEM is correct; the full scale side impact simulation results are actual and credible; the computer simulation technology mastered in this paper has practicability.The side impact FEM, described in this paper, can be applied to finish a computer simulation and can get a correct result. The result can be used to make advice to improving the safety of a car.In the end of this paper, some suggestions of improving the car's quality are made: strengthening the floor, doorframe and door to lessen the deformation of the car which can make sure the passenger get enough living space to avoid injury, decelerating the speed of the impact second to lighten the injury for chest. The simulation results show that these suggestions would improve the safety of the car.This paper is divided into eight chapters. Contents are detailed as fellows:Chapter one is mainly about the main topics, methods and significances of this paper, the current situation of the vehicle passive safety and the simulation technology in the vehicle engineering in the world, the function of the VPG. The side impact safety is one hot point in the field of passive safety research, which has caught more and more attentions. Improving vehicle-safety and gaining experience are the substance.Chapter two is about the MDB. The structure and functions of MDB is introduced. A finite element model of MDB is built and simulated for calibrating test. The simulation result proves that the FEM of MDB is validated to satisfy the requirement of full scale side impact simulation.Chapter three is about the side impact dummy, which includes the calibrate process and testing methods. According to the side impact dummy calibrate process and referring to the calibrate results, this paper set up the Dummy FEM and carried out calibrate simulation. On the base of simulation results, the Dummy FEM is corrected to meet the requirement of calibrate test, and can gain exactly the impact mechanism responds of body in the case of side impact simulation test. The research of Dummy calibrate process and calibrate methods are helpful to perfect the Dummy FEM.Chapter four is about the methods of full scale vehicle FEM. In this paper, the key points of building FEM are described as fellows: how to leave out these unimportant characters for the simulation result to improve the calculation speed, how to control the qualities of mesh, how to assemble the parts using different joint-element, how to define the materials, how to get out suspension and tire FEM from the model-bank in VPG.Chapter five is about the side impact simulation program. Referring the side impact procedure in the VPG/Safety module, the step of building a full size vehicle FEM is described and the step of contact define is emphasized.Chapter six is about the simulation results. From three different aspects—vehicle,MDB,dummy, this paper compared the simulation results with test results. Concludes drawn from comparative results is: the vehicle,MDB and Dummy FEM is correct; the full size side impact simulation results is actual and credible; the computer simulation technology mastered in this paper has practicability.Chapter seven is about the scheme of ameliorating the body structure. The simulation results show that the scheme would improve the safety of the car. That proves the simulation technology is worth to be applied to vehicle design.Chapter eight is about the review of this paper. The research get these result: the side impact simulation results are almost consistent with the testing data. The vehicle FEM is practicable for the vehicle structure design. Besides that, some topics needed to be researched more are listed.