Abstract: The purpose of the article is to optimize the strength of weak positions to improve product reliability by studying the failure behavior of the door inner handle assembly in the process of use, so as to reduce the failure rate of the aftermarket and avoid user complaints. The article analyzes the failure of the door inner handle assembly of a heavy duty vehicle door system, and with the help of six sigma quality tools, the failure is confirmed and analyzed to find out the key influencing factors affecting the failure of the door inner handle assembly. By increasing the reinforcement to improve the strength of the inner handles, the computer aided engineering (CAE) comparative analysis, before and after the improvement of the product suffered the maximum stress, the inner handles assembly own strength increased by 36%, which can effectively solve the cracking, fracture and other problems caused by the lack of strength. Meanwhile, the tracking verification of the improved product shows that the after sales failure rate is reduced by more than 25%, which is a good effect of the improvement. This study can also provide reference for the failure analysis of other related parts.

Key words: Inside opening puller; CAE analysis; Failure behavior; Maximum stresses

摘要： 文章旨在通过研究车门内开拉手总成在使用过程中的失效行为，以优化薄弱位置强度 来提升产品可靠性，从而降低售后市场故障率，避免用户抱怨。文章对某重型汽车车门系统 内开拉手总成失效进行分析，借助六西格玛质量工具进行故障确认、分析，找出影响车门内 开拉手总成失效的关键影响因子。通过增加加强筋来提升内开拉手强度，经计算机辅助工程 （CAE）对比分析，改进前后产品所受最大应力，内开拉手总成自身强度提升 36%，能够有 效解决强度不足导致的开裂、断裂等问题。同时对改进后产品跟踪验证，售后故障率降低超 过 25%，改进效果良好。该研究也可为其他相关零部件产品失效分析提供参考。

关键词: 内开拉手；CAE 分析；失效行为；最大应力