Investigation on compression-springback behavior of metal semi-cylindrical shell in thermal environment

Abstract

The elastic-plastic deformation of materials provides limited displacement for metal gaskets, so as to ensure the sealing performance of flanges. In order to study the sealing performance of a novel metal gasket with a convex structure of a semi-cylindrical shell between two flanges, the compression-springback behavior of semi-cylindrical shell is investigated. By introducing the rebound and anti-coupled system consisting of the compressed body and the resilient body, meanwhile based on von Kármán nonlinear theory and Mises yield criterion, the incremental thermo-elastoplastic stress-strain constitutive relation of the semi-cylindrical shell is theoretically derived. Utilizing the finite difference method in space domain and nonlinear term iteration technique, the plastic stage problem including the semi-cylindrical shell and the sheet with flattening single-corrugated structure is solved. The influence factors of material properties, temperature, geometrical parameters of semi-cylindrical shells and cyclic loads are considered. Results show that the compression-springback behavior of nickel-based alloy is better than that of stainless steel in thermal environment, while the compression-springback behavior of stainless steel is closed to that of nickel-based alloy at room temperature. The width of semi-cylindrical shell and depth of base material significantly affect the compression-springback behavior of stainless steel. In addition, the cyclic load can cause the plastic hardening of stainless steel.