The Influence Of Tire Model On Vehicle Collision Simulation Results

In the condition of front impact,40% offset collision,25% small overlapping offset collision and vehicle rolling,the tire is an important path of collision force transmission.Modeling high precision tire finite element model is of great significance to improve the accuracy of the vehicle crash finite element simulation.In order to ensure the calculation efficiency of the tire finite element model in the vehicle simulation,the minimum size of the unit in the tire finite element model is limited.Both simplified simplification modeling method with high simplification and the low simplified multi-layer composite structure modeling method must simplify the model of the tire structure.There are differences between the structure and the actual physical structure,so the parameters of the simplified structure need to be corrected to ensure the accuracy of the simulation.However,researchers had not put forward a good method for parameter correction in tire finite element modeling.Aiming at solving above problems,this paper taking the 165 R 14LT tire,the micro car FE crash model and the TOYOTA Yaris FE compact model as the research objects,finished a compound structure FE tire model with low simplification and a tire FE model considering tire blowout simulation,and applied to vehicle crash simulation.The main research work is as follows:Firstly,obtained the section CAD drawings of the 165 R 14LT radial tire and the cross section of the tire,and commissioned the tire manufacturer to carry out the uniaxial tensile test of the rubber raw material of the tire surface colloid,the side colloid and bead filler,this paper got the test data of the rubber material of the main tire structure.Secondly,according to the design data of the tire,the finite element mesh is divided according to the structure of each part.Considering the application of the model in the whole vehicle FE simulation,the minimum size of the elements in the model is restricted,the cord and the cord layer were properly simplified,and the structural materials were given to each part by the data of the rubber uniaxial tensile test and the literature.The model of tire pressure and atmospheric pressure was established by combining with the wheel hub finite element model,and a complete FE tire assembly model was finished.Thirdly,the radial,transverse and longitudinal quasi static stiffness tests and the drop hammer radial impact were tested on 165 R 14LT radial tire to obtain the quasi static stiffness characteristics of the tire and the radial stiffness characteristics of the drop hammer impact,and establish corresponding simulation model for simulation analysis.Then,based on the tire radial drop impact test conditions,the radial drop impact simulation of the tire was simulated,and the four parameters of the tire cord were used to design the test samples by the Latin hypercube test method.Based on the simulation results of the sample,the model of the surface response agent model was built,and the multi Island genetic algorithm(Multi-lsland GA)was used to reverse the tire tire cord model parameters to improve the simulation accuracy of the tire finite element model.For the tire finite element model used in the 25% small overlapping offset collisio simulation,the sudden reduction in the pressure of tire burst was simulated by setting the time history of the key to control the tire pressure in the air pressure model.For the tire finite element model used in in the micro car rollover simulation,parameter reverse technology was used to correct the lateral quasi static stiffness of tire,according to the test data of transverse quasi-static stiffness of tire.Finally,the tire model,which was verified by radial impact test,was applied in the 100% rigid wall collision and the 40% offset crash model to analyze the influence of the radial stiffness error on the collision force transmission path,the structure energy absorption,the occupant cabin intrusion and the acceleration waveform in the whole vehicle simulation.The tire blowout simulation was applied to the TOYOTA Yaris 25% small overlap offset simulation to analyze the influence of tire blowout factors on the simulaiton results.The 165 R 14LT model radial tire model,which matched the lateral quasi static stiffness test of the tires,was used for the rolling simulation,and analyzed the influence of tire lateral stiffness on the attitude of the vehicle when drop to the ground in the rollover test.