Numerical investigation of residual stresses in welded joints of cylindrical shell

Abstract

Welded cylinder structures such as pressure vessels and pipes for transportation have been applied in power stations, aerospace, and shipping industries. The study of weld-induced residual stress is vital in predicting the life of welded cylinder vessels. Depending upon the required diameter and length, they are welded by either circumferential welding or longitudinal welding. In the present work, a sequentially coupled thermal, structural analysis is carried out on circumferential and longitudinal butt weld joints of AH-36 cylinder components. The thermal field distribution and subsequent residual stresses during Gas Tungsten Arc Welding (GTAW) are studied. The moving heat source considered for analysis is based upon Goldak’s double ellipsoidal model. The weld-induced axial and hoop stresses are evaluated on both the outer and inner surfaces of the cylinder. The results for circumferential and longitudinal butt weld joints are compared. The magnitude of peak hoop and axial stresses in longitudinal butt weld joints are 45% and 95% higher than in circumferential butt weld joints. The developed analysis model, used to evaluate the thermal histories and residual stresses, is validated with experimental measurements.