Optimum Design And Performance Study Of Carbon Fiber Reinforced Plastic Bumper

Lightweight of automotive is an effective way to achieve safety,energy saving and environmental protection.Material lightweight is an important mothed of automotive lightweight,carbon fiber reinforced plastic has good mechanical properties,which can be applied into automotive to greatly reduce the quality of the automotive,and has a very good effect on reducing automotive fuel consumption and reducing vehicle life-cycle exhaust emissions.On the basis of ensuring automotive safety performance,to achieve automotive lightweight is a hot field of automotive research.As a key component of the automotive,bumper system is usually hit firstly in the traffic accident.Bumper can reduce the hurt of pedestrians and occupants,and can also reduce the damage of the automotive.This thesis takes the front bumper as the research object,and the optimum design and performance study of carbon fiber reinforced plastic bumper are carried out.First,the carbon fiber composite test specimen was prepared for the tensile test and the bending test to obtain the material related mechanical properties.The experimental models are constructed;the stretch simulation and the bend simulation are carried out in LS-DYNA.Finite element simulation is effective and reliable by comparing the simulation curve with the test curve.Second,according to GB17354-1998 low-speed crash test standard,the bumper-pendulum collision simulation models are established.The low-speed collision simulations of steel bumper and initial design of carbon fiber reinforced plastic bumper are conducted in LS-DYNA.The maximum internal energy,the maximum displacement and the maximum stress of the bumper during the collision are selected as the evaluation parameters of the collision performance,and the collision performances of the steel bumper and the carbon fiber reinforced plastic bumper are compared.The carbon fiber reinforced plastic bumper beams are provided with different laying thickness,different laying angles and different stacking sequences to conduct collision simulations for performance study.Third,the carbon fiber reinforced plastic bumper beam laying optimization is conducted.One hundred times Latin hypercube samplings are carried out in MATLAB to construct the design matrix.The design matrix is imported to HyperStudy for the experimental design.By experimental sample data,and the HyperKring method,the approximate model is constructed.The genetic algorithm is chosen as the optimization method to optimize the approximate model,and the optimal stacking form of carbon fiber reinforced plastic bumper beam is obtained.Finally,the optimal stacking form of carbon fiber reinforced plastic bumper beam was simulated and the accuracy of the optimal parameters is verified.The performance parameters of the optimized carbon fiber reinforced plastic bumper and the original steel bumper are compared and analyzed,the results show that the optimized carbon fiber bumper has better collision performance,and the quality is significantly reduced.The results show that the the carbon fiber reinforced plastic has important significance for the reduction of automobile.