大型货车车架失效分析及试验研究

Failure analysis and experimental study on truck's frame

针对某汽车制造企业制造并投放市场的某大型载货汽车在行驶几个月时出现的车架早期裂纹甚至断裂的情况,利用有限元分析软件ANSYS对其进行了有限元建模,模态分析和在路面激励下动态响应分析,并对车架进行多种路况下的动态应变电测试验和振动试验。有限元分析结果表明,路面激励在8 Hz附近时,车架应力及位移响应较大。动态试验中车架综合应力达到165.8 MPa,此外11.97、23.93、35.90 Hz低频信号对各加速度测点的振动产生较大影响。根据有限元分析和试验结果分析车架失效原因,并为该车型后续车架结构的设计和优化工作提供设计依据。

Aiming at the problems that cracks and fracture appeared in the vehicle frame of a brand heavy truck after driving a few months,a finite element model was established to analysis structural vibrating modes and random dynamic vibrating responses excited by road configuration by using software ANSYS.The finite element analysis results show that stress responses and displacement responses of the frame caused by 8 Hz road excitation are quite large.Dynamic strain measurement and vibration experiments were performed under various road conditions.Testing results show that the maximum comprehensive stress of the frame is 165.8 MPa and low-frequency signals of 11.97,23.93,35.90 Hz have strong influences on the vibration of every acceleration testing point.The failure reasons are concluded by analyzing the results of finite element analysis（FEA） and the experiments.The analysis results of FEA in this paper can be used for the optimization of the vehicle frame and engineering design and have reference value for the design and optimization of similar vehicle types.