Numerical and experimental investigation of the residual stress distribution in shell-tube pressure vessels weld joint

Tube-sheet to tube weld joint is a critical section in shell-tube pressure vessels. The leakage and failure are two common problems that happen in this joint. The tensile residual stresses associated with welding can play a major role in the mentioned problems. In the present study, residual stresses distribution is investigated by Finite Element Method and experimental tests. The joint includes a circumferential fillet weld in one pass by Gas Tungsten Arc Welding process. The thermo-mechanical behavior of the joint is simulated by a 2D axisymmetric model using a subroutine developed in ANSYS software. The thermography Method used to thermal analysis verification and the Whole Drilling Strain Gauge under Post Weld Heat Treatment used to mechanical analysis verification. The numerical and experimental results show that the residual stress as von Mises criteria is about 105 MPa and as stress intensity criteria is about 115 MPa in root of Tube-sheet to tube weld joint. Maximum defference between numerical and experimental results, in thermal analysis and mechanical analysis, is about 11% and 18% respectively.