内压轴向位移载荷作用下波纹管多轴疲劳寿命预测

Prediction of multiaxial fatigue life of bellows under internal pressure and axial displacement load

以某工程用波纹管为研究对象,采用新提出的MSWT(Modified Smith-Watson-Topper)临界面模型预测了波纹管在内压-轴向位移作用下的多轴疲劳寿命。由于波纹管承受低周位移载荷时在波峰波谷处发生塑性变形,故以塑性应变幅与最大正应力重新组成一个新的损伤参量DP,并定义最大DP值所在的平面为疲劳破坏发生的临界面。利用Abaqus软件对波纹管进行数值模拟,基于数值分析结果,MSWT模型预测不同工况下波纹管的疲劳寿命分别为3388次与6059次,与试验结果吻合程度较好,可为波纹管的设计开发提供一定的参考。

In this study,the bellows for a project was chosen as the research object to investigate the multiaxial fatigue life of the bellows under combined loading conditions of internal pressure and axial displacement using a newly proposed Modified Smith-Watson-Topper(MSWT)critical plane model.Due to the occurrence of plastic deformation at the peaks and valleys of the bellows under low-cycle displacement loads,a new damage parameter,DP,composed of plastic strain amplitude and maximum normal stress,was formulated.The critical plane,where the maximum DP value occurs,was defined as the plane where fatigue failure takes place.Numerical simulations of the bellows were conducted using the Abaqus software.Based on the results of the numerical analysis,the MSWT model predicts fatigue life of bellows under different operating conditions to be 3388 cycles and 6059 cycles,which shows good agreement with experimental results.This provides a certain reference for the design and development of bellows.