某导弹发射装置在进行锁制力值测试时出现了锁制机构锁制失效现象,经检查是锁制机构挡件断裂所致。针对挡件断裂的可能原因列出了故障树,通过对故障树中的可能失效因素进行排查和分析,确定断裂原因为挡件后腿根部圆角过小引起应力集中增大所致。用ANSYS软件对挡件根部圆角大小与应力的关系进行了分析,从分析结果看倒圆有很明显的改善应力集中的作用,因此,将挡件应力集中部位进行了设计改进,解决了挡件应力集中引起断裂的问题。

Failure occurred as locking of the detent mechanism during the locking force test for a launcher. The launcher was inspected and the failure reason was the stopping of detent mechanism fractured.The fault tree was listed for the possible reasons of the stopping fracture.Possible reasons in the fault tree were analyzed and inspected,it was certain that the reason of the stopping fracture was the smaller rounding increases stress concentration. The relation between rounding and stress on the back stopping was analyzed with ANSYS software,which showed that rounding improved obviously stress concentration.So the stress concentration position of the stopping was improved on design to solve the problem of the stopping fracture.