Performance Analysis And Structural Optimization Of BAJA Racing Frame

BAJA racing is an all-terrain vehicle with outstanding off-road performance.It can drive in harsh terrain such as deserts,mountains and hills.As the main load-bearing component of the BAJA frame,under the impact of various and variable load conditions,the performance of the frame is very important for the safety and reliability of the car.Therefore,it is an unavoidable process to analyze and optimize the performance of Baha’s frame.This article takes the first-generation Baha of a company as the research object.The main content are as follows:(1)Performancing analysis of Baja frame.HyperMesh was used to perform preprocessing such as geometric cleaning,mid-plane extraction,meshing,and welding simulation on the frame model,thereby establishing a finite element analysis model of the frame with higher quality.Performances of the frame were analyzed using vertical runout,full-load torsion,emergency braking,and emergency cornering.According to the stress and displacement distribution of the frame under the four working conditions,the weak link of the frame structure was found,and combined with the vehicle layout and the axle load distribution,the triangular frame diagonal brace layout method was used to improve the design of the frame.The improved stiffness and strength performance of the improved frame are significantly improved compared to the original frame.Finally,modal simulation is used to analyze the dynamic performance of the frame,which shows that the improved frame meets the use conditions.(2)Optimizing the improved frame.The sensitivity analysis method was used to select 38 sets of pipe fittings from the frame structure.The thickness of the pipe fittings was used as an optimization design variable.200 sets of uniformly distributed samples were taken using the Hamsley sampling method and constructed using the RBF radial basis function method.An approximate model based on frame stiffness and modal was presented.Finally,the global response surface optimization algorithm is used to carry out multidisciplinary lightweight optimization of the frame.The optimization results show that the mass of the frame is reduced by 20.96 kg,which is 13.49% lower than before optimization,and the stiffness and modal performance are also improved,which verifies the effectiveness of the multidisciplinary optimization design method used in this paper.(3)Performing a crash safety analysis on the optimized frame.A finite element analysis model of a frame with 100% contact with rigid walls facing at a speed of 50 km / h was established.By analyzing the acceleration curve and the deformation of the frame at different times,it is verified that the frame has a certain impact resistance.