冯志远，苏铁熊，王军

（中北大学 机械与动力工程学院，太原 030051）

摘要：本文针对某柴油机连杆进行瞬态动动力学分析，得到载荷谱及结果文件。利用修正的Miner累积损伤准则，结合Nsoft软件，对连杆进行疲劳寿命预测。考虑到不确定因素对连杆寿命值影响，对考察部位进行了灵敏度分析。结果表明:当载荷幅值减少10%时，连杆寿命值提高5倍；当残余应力达到-100MPa时，寿命值相比较没有经过强化处理的寿命值提高了5.17倍。该研究方法能够对实际生产中加强连杆疲劳强度提供较高的参考价值。

关键词：疲劳寿命；连杆；灵敏度；残余应力

Abstract: This paper makes an analysis on the transient dynamics of Diesel Engine of connecting rod by using of the finite element simulation software to get the required load spectrum and outcome documents. Using the Miner cumulative damage criteria and Nsoft software,the life of connecting rod was completely predicted. Taking into account the effect of uncertainty of the connecting rod life, conduct inspect parts of the investigation sensitivity analysis. According to the sensitivity analysis result, the fatigue life reduces by 5 times when the load amplitude increases by 10%, and the fatigue life increases by 71 times when the surface residual compressive stress teaches 250MPa. The presented approach provides a reference for predicting theconnecting rod fatigue life and improving its structural design.

Key words: fatigue life；connecting rod；sensitivity；residual stress