某重型载货汽车车架柔性化建模及疲劳分析

Fatigue Analysis of Flexible Truck Frame for Heavy Truck

针对某重型载货汽车车架局部出现的疲劳寿命问题,通过有限元理论生成车架的模态中性文件,并对车架进行静力分析及强度校核。利用虚拟样机技术,建立考虑车架弹性的整车刚柔耦合模型,并对刚柔耦合整车模型进行随机路面不同速度下的整车动力学仿真,提取车架关键边界载荷谱。利用S-N疲劳设计方法,选用疲劳分析软件nCode Design-Life对车架进行疲劳可靠性分析,得到车架在不同工况以及不同车速下的疲劳寿命结果及损伤位置。结果表明:车架的最小寿命满足行驶要求,并为车架的优化设计提供了理论依据。

With respect to the fatigue life problems of the heavy truck frame,The MNF of the frame was generated by FEM,and the static analysis and strength check of the frame were carried out.The virtual prototype technology was used to establish the rigid-flexible coupling model of the vehicle considering the elasticity of the frame.The rigid-coupling model was used to simulate the vehicle dynamics at different speeds on a random road surface to extract the critical boundary load of the frame.The fatigue reliability analysis of the frame adopted the S-N fatigue design method and the fatigue analysis software nCode Design-Life to obtain the fatigue life results and damage positions of the frame under different working conditions and speeds.The results show that the minimum life of the frame can satisfy the driving requirements and provides a theoretical basis for the optimal design of the frame.