扣件DI弹条非正常部位断裂原因分析及结构优化

通过对DI弹条非正常部位断裂的研究,发现扣件安装时弹条与铁垫板安装孔发生接触,致使弹条在中肢与尾部圆弧过渡区域产生应力集中,发生早期疲劳断裂。本文在研究弹条结构及安装方式的基础上,在弹条的中肢与尾部圆弧过渡区域引入"凹面"结构,对弹条进行结构优化,并通过扣压力和疲劳性能检测、实验室疲劳断裂检验、现场试铺检验等对带有优化"凹面"结构的DI弹条性能进行检测。结果表明:优化后的弹条扣压力和疲劳性能均合格,且能有效抑制因接触产生的非正常部位断裂,提高弹条性能。

Fracture Analysis and Structural Optimization of Abnormal Part of Fastener DI Spring Clip

In this paper,fracture at abnormal part of DI clip is studied.It is found that the clip and the iron backing plate installation hole is contacted when fastener is installed,resulting in stress concentration at the transmission zone of middle limb and the tail arc.Thus,fatigue fracture at early age is occurred.Based on the research on the clip structure and installation method,a concave structure is introduced into the transmission zone of the middle limb and the tail arc.The clip structure is optimized.The optimized clips with the concave structure have been tested including the clamping force of fastener and fatigue test,laboratory fatigue fracture inspection and field trial test.It shows that the optimized clip clamping force of fastener and fatigue performance are up to standard.Also,the abnormal part fracture caused by contact is effectively prevent and the clip performance is improved.