超高压阀体自增强及疲劳寿命分析

The Research of Autofrettage and Fatigue Life on Ultrahigh Pressure Valve

分析了高压阀门在发展中遇到的问题,选用某高压阀门阀体作为研究对象,对其进行了有限元静力学分析,找到了结构的薄弱之处。依据材料的包辛格效应,对阀体的自增强过程进行仿真分析,并对自增强过程中阀体的应力进行了分析,从阀壁内部应力的角度说明自增强能改善阀体的应力分布状态。通过对比自增强处理过的阀体与未经自增强处理的阀体在80 MPa下的应力分布图可知,前者应力分布更加均匀,应力最大值较小,改变了内表面应力最大的状态。通过疲劳分析可知,自增强处理能提高阀体的疲劳寿命达11倍之多。

After analyzing the problems encountered in the development of the high pressure valve,we selected a high pressure valve body as the study object,which was simulated and analyzed by applying the finite element software.As a result,the weakness of the structure was found.According to the Bauchinger effect of the material,the autofrettage process of the valve body was simulated.Then,the stress of the body was researched,which demonstrated that the autofrettage can improve the stress distribution.Meanwhile,under 80 MPa operating pressure,the result of numerical simulation shows that the autofrettage valve body has a more homogeneous stress distribution and smaller peak stress.Moreover,the autofrettage process changes the state that the maximal stress is located in the internal surface.Furthermore,the fatigue analysis shows that the fatigue life of the autofrettage valve body is improved by 11 times.