Abstract: The subframe is an important structural component between the body and the suspension, which carries the force and torque between the tire and the body, so the fatigue life, strength and stiffness of the subframe directly affect the safety and stability of the whole vehicle, and the fatigue life analysis and research of the subframe is an important task in the development of the subframe. Based on the fatigue damage analysis of the subframe of loop load, this paper first introduces the collection and damage analysis theory and analysis process of loop load, and uses Nastran solver and nCode analysis module to carry out fatigue damage analysis. Then, it focuses on how to optimize the fatigue damage of the subframe, and puts forward a series of optimization methods and cases. The analysis results show that the optimization method is effective and has an important guiding role for the structural design of subframe.

Key words: loop load; subframe; fatigue damage; nCode; case

摘要： 副车架是车身与悬架之间重要的结构部件，承担着输送轮胎和车身之间的作用力和扭 矩，所以副车架自身的疲劳寿命和强度、刚度等直接影响了整车的安全与稳定，对副车架的 疲劳寿命分析和研究是开发副车架的重要任务。文章基于路谱载荷的副车架疲劳损伤分析， 首先介绍了路谱载荷的采集和损伤分析理论及分析流程，利用 Nastran 求解器和 nCode 分析 模块开展疲劳损伤分析，之后重点讲述了副车架疲劳损伤如何优化，提出了一系列的优化方 法及案例，分析结果表明优化方法有效，对副车架的结构设计有重要的指导作用。

关键词: 路谱载荷；副车架；疲劳损伤；nCode；案例