某商用车后桥静力学及疲劳分析

Statics and Fatigue Analysis of a Commercial Vehicle Rear Axle

摘要: 针对后桥板簧座焊缝处易产生疲劳破坏的问题，首先建立了后桥有限元模型，为减少计算量，并尽可能的保证仿真精度，对后桥有限元模型进行了整体简化，几何清理等处理，随后对模型进行网格划分并创建边界条件。本文选取最大垂向力工况对后桥进行静力学分析，在后桥的两个板簧座上施加垂向静态载荷，垂向载荷的大小由后轴满载静载计算得出，随后便可对后桥进行强度计算，得到汽车后桥在最大垂向力工况下的应力及位移云图。采用惯性释放的方法，求解后桥在各个单位载荷下的应力状态，基于惯性释放仿真结果，在Ncode中结合材料S-N曲线并根据后桥满载轴荷定义时间序列载荷，运用线性疲劳损伤理论对后桥进行疲劳寿命评估。观察后桥不同位置的损伤状态，为后桥结构设计提供参考。

Abstract: In view of the problem that fatigue damage is easy to occur at the weld of the rear axle plate spring seat, the finite element model of the rear axle was first established. In order to reduce the calcula-tion amount and ensure the simulation accuracy as much as possible, the finite element model of the rear axle was simplified and cleaned geometrically, and then the model was meshes and boundary conditions were created. In this paper, the maximum vertical force condition is selected to carry out static analysis of the rear axle, and the vertical static load is applied on the two plate spring seats of the rear axle. The vertical load size can be calculated by the full load of the rear axle static load, and then the strength of the rear axle can be calculated, and the stress and displacement nebulae of the rear axle under the maximum vertical force condition can be obtained. The stress state of the rear axle under each unit load was solved by the method of inertia release. Based on the inertial simulation results, the S-N curve of the material was combined in Ncode and the time series load was defined according to the full load of the rear axle. The fatigue life of the rear axle was eval-uated by the linear fatigue damage theory. The damage state of rear axle at different positions was observed to provide reference for the structural design of rear axle.