中文摘要：

应力幅、应力集中和附加弯矩3因素是导致压缩机活塞杆发生疲劳断裂的主要原因。常规的理论计算不能有效解决多因素耦合作用条件下活塞杆的强度问题,因此提出了一种虚拟的可靠性试验方法。采用ANSYS软件和C＋＋编程语言搭建虚拟试验平台;依据弹性力学的变形协调条件,推导出活塞杆螺纹的应力分布计算式,用来验证虚拟试验平台的有效性;根据中心复合法设计随机参数的试验样本点,通过VC窗口程序更改APDL编译的宏文件,自动完成虚拟试验过程,获得结构响应的一组样本点;基于响应面方法建立极限状态方程,分析可靠性灵敏度,为活塞杆的设计提供理论指导。

英文摘要：

Three factors including stress amplitude,stress concentration and additional moment,are main reasons causing fatigue fracture of the piston rod of compressor.Common theoretical calculation can＇t availably resolve the problem for strength of piston rod under multi-factor coupling,so a method for virtual reliability test was proposed.ANSYS and C＋＋ were used to build virtual test platform;the stress distribution formula of piston rod thread was deduced in accordance to the deformation compatibility principle of elastic mechanics in order to verify the validity of virtual test platform;the testing sample points of random parameters were designed based on central composite method,and the VC program of dialog box was used to modify macro file compiled by APDL to finish virtual test automatically and get a group of sample points of structure response;the limit state equation was given based on response surface method to analyze both the reliability and sensitivity,thus providing theoretically a reference for the design of piston rod.