某离合器铆钉连接的失效分析与优化设计

The Failure Analysis and Optimization Design of a Clutch Rivet Connection

某变速器离合器铆接结构在做耐久台架试验时发生断裂。通过对铆钉材料化学成分、宏观断口、微观断口等进行失效分析,判定铆钉断裂为疲劳断裂。结合铆接工艺过程、试验工况下结构有限元分析与疲劳寿命分析方法,对铆钉进行优化设计。基于试验,修正铆钉疲劳寿命仿真分析方法,直径φ4的铆钉,CAE疲劳寿命在55万次左右,与试验相匹配。结合疲劳寿命仿真分析方法提出四种优化设计方案,对现有铆钉表面热处理,增加铆钉位置接触面积,增加铆钉数量,增大铆钉直径。四种方案,仿真分析与试验都能满足铆钉的疲劳寿命要求。基于设计成本的考虑,最后选择的是铆钉表面热处理,由此说明,用有限元技术预测铆钉的疲劳寿命是可行的,本研究可为铆接设计作参考。

The riveting structure of a transmission clutch was fractured during the endurance bench test.Through the failure analysis of the chemical composition,macroscopic fracture and microscopic fracture of the rivet material,the rivet fracture is judged as fatigue fracture.Combined with riveting process,structural finite element analysis under test conditions and fatigue life analysis methods,the optimal design of rivets is carried out.Based on the test,the modified rivet fatigue life simulation analysis method shows that the CAE fatigue life of rivet with diameterφ4 is about 550,000 times,which matches with the test.Combined with the fatigue life simulation analysis method,four optimization design schemes are put forward.Heat treat the surface of the existing rivets,increase the contact area of the rivets position,increase the number of rivets and increase the diameter of rivets.The four schemes,simulation analysis and test,can meet the fatigue life requirements of rivets.Finally,we select the heat treatment method,which spends at least.Therefore,it is feasible to use FEA technique to predict the fatigue life of rivets,the study can be used as the reference for the rivet connection design.