基于ANSYS的压力容器表面凹坑缺陷安全评定分析

Safety Assessment Analysis of Pressure Vessel Surface Pit Defect Based on ANSYS

采用通用有限元程序ANSYS建立了移动式压力容器筒体外壁表面凹坑(轴向和周向)的有限元模型。结合筒体表面凹坑的应力理论计算,研究探讨了在恒定内压下,筒体表面凹坑缺陷处的应力分布与凹坑几何尺寸之间的关系。以第三强度理论作为仿真终止判据,获取凹坑各几何参量的阈值,利用MATLAB对阈值进行最小二乘拟合,绘制出凹坑缺陷的安全评估参考曲线。拟合结果表明:轴向和周向凹坑对筒体局部结构强度的影响不同,对应的安全评估参考曲线存在区别。

Finite element models of pits（ axial and circumferential ） on transportable pressure vessel cylin-der wall surface are established by ANSYS. Combined with theoretical stress calculation of the cylinder surface pits, the relationship between stress distribution around pits of cylinder surface and pits geometry is analyzed un-der a constant internal pressure. The thresholds of geometry are acquired by taking the third strength theory as simulation terminated criterion, and safety assessment reference curves are drawn through least squares fitting carried out on the threshold with MATLAB. The results show that axial and circumferential pits have different impacts on local structure strength of the cylinder, and the corresponding safety assessment reference curves are various.