Research On Lightweight Of Coach-body Frame With Steel-aluminum Combined Structure

The paper took the bus body frame of steel-aluminum combined structure as the research object, completed the statics analysis and dynamic analysis of the vehicle combined with the finite element theory and the engineering test. The car’s strength, stiffness and dynamic properties were found out and the lightweight design was better guided. The main content of the research are as follows:First of all, simplified the model according to the UG graph that the company provided. Bus frame finite element model is established in the Hyperworks software, and the boundary condition was reasonably set; Do statics analysis of four working conditions(level, ultimate torsion and bending, emergency braking emergency turn). Bus skeleton strength was test and compared with the finite element calculation result.Secondly, do modal analysis and frequency response analysis on the bus frame structure. Do frequency response analysis on the basis of modal analysis. Making the motor and the joint of body frame as a frequency excitation point, obtain the displacement response of the body frame key location.Finally, sensitivity analysis was carried out on the body frame structure, with the minimum quality as the design goal, with body first-order torsion frequencies, bending and torsion stiffness as constraint conditions, and the body frame torsional frequency, bending stiffness and torsional stiffness sensitivity about the bar thickness and quality of sensitivity was solved. According to the results of sensitivity analysis, choose the need to optimize the bar and complete the body frame lightweight analysis.