Design And Structural Optimization Of Improved Bogie For H-Bahn Vehicle

In this paper,with the improved bogie of H-Bahn vehicle taken as the research object,the overall design and finite element analysis are mainly accomplished.In the worst abnormal condition,different structural optimization methods are used,with multiple optimization adjustments in different point of view,we obtain the optimal solution of the frame structure.At last,the static strength,fatigue strength and modal of the optimized frame are analyzed.The main points and conclusions of this paper are as follows:1.The improved bogie of H-Bahn vehicle and its structure are designed and analyzed.The loads of the frame under abnormal and normal operation conditions are obtained.After the boundary conditions are set,the static strength check and fatigue strength check of the frame are completed respectively.The result shows that the strength of the frame meets the requirements.The modal analysis of the frame before and after optimization is carried out.Combined with the pre optimization analysis,the overall structure of the frame has the optimization potential.2.Using the topological optimization method,which is based on the variable density method,according to the actual structure of the frame and the size and layout of each structure,add plates to fit the square beam and optimize to get the preliminary convergence result.After the local optimization adjustment of the welding part between the brake shoe seat and the crossbeam where the obvious stress concentration appears in the corresponding stress check,the second topology optimization of the new frame structure is carried out to obtain the feasible solution.Considering to reduce the new structure,analyze scheme 1 and scheme 2,and compare the solution results,we adopt scheme 2 frame structure.At this time,the maximum stress of the whole new frame structure is reduced from 265.4 MPa to 164.6 MPa,so the optimization effect is obvious.3.As the key component of bogie load and support,frame lightweight plays a great role in reducing the vehicle quality.Therefore,on the premise of ensuring that the strength of the frame meets the requirements,the frame lightweight optimization design is carried out.In this paper,the main lightweight design is divided into the first and second frame multi-objective thickness optimization.The first multi-objective thickness optimization and pre optimization,as well as the preliminary topology optimization,lay the foundation for the subsequent optimization.The second multi-objective thickness optimization is mainly aimed at lightweight design,limiting the overall maximum stress of the frame,taking into account the purpose of lightweight and low stress concentration,and obtaining the final optimal solution of the finite element optimization of the frame.4.The new structure after several structural optimizations under the worst condition,the static strength of the frame should be checked under the complete abnormal condition.Because the thickness reduction at the center pin plate of the hanger and the fixed shaft plate of the motor changes too much,a new stress concentration appears obviously under some working conditions.After the size adjustment,the static strength is checked again,and the maximum stress is only 161.2 MPa.After optimization,the total volume of the frame is reduced by 12.4%,the maximum stress drop of the whole frame is 104.2 MPa,and the maximum stress is reduced by 39.3%.The result shows that the optimized model can meet the size constraints of the original frame.Considering the processing technology,the fillet square beam strengthened in the new area can be welded to the original structure of the frame with Q345 seamless steel pipe,which is convenient for the assembly and manufacture of the frame.