Analysis of Plane Displacement of Pressure Vessels with Defects

Abstract

Aiming at the problem that the internal defects of the pressure vessel are not easy to detect, the out-of-plane displacement method is used to study it. The out-of-plane displacement field of circular flat plate heads with defects is obtained by the method of elastic theory analysis and compared with the finite element method to verify the accuracy of the finite element method. Based on the finite element method, the effects of vessel material, pressure load, defect shape, and defect size on the first-order out-of-plane displacement derivative are studied. The results show that the material of the container has little effect on the out-of-plane displacement. The first derivative of out-of-plane displacement increases linearly with the increase of pressure, and this relationship will not change with the increase of pressure. With the increase of defect aspect ratio, the maximum value of the first derivative of out-of-plane displacement increases gradually. When δ ˃ 9, the defect is detectable. The research results lay a theoretical foundation for the internal defect detection of pressure vessels based on digital speckle shearing interferometry.