Estimation of weld induced residual stresses in thin cylinders using indirect coupling method

Abstract

Abstract For the idea to launch utility-based design values of distortions in ship sections a extended term objective is to specify an optimal welding techniques and to optimize distortion also to minimize residual stresses due to welding. It involves multifarious physical experience. The latent utility of FEM calculation and easy systematic and parametric terminology is established by means of a number of examples. imprecision start partially from thermal deformations due to cutting, welding and partly as dimensional difference due to human aspects and this boosts the production expenses. The objective of the current work is to simulate some typical welding joints. This included establishing an arbitrary movable heat source, measurements of the temperature distribution in a steel cylinders, calculation of equivalent shrinkage force by inherent strain method measurement of distortions and stresses and finite element analysis by ANSYS. The purpose of the simulation or calculation is to obtain values for in plane reduction and out of plane buckle. For the calculation a 3-D model of a cylinder assuming a 3-D stress field works quite well. The heat source can be moved in straight lines along the cylinder or moving in circumferential direction, by use of the developed simplified APDL subroutine. The FEM results are here in general lower than those experimentally measured. The distortion and stress patterns are fair. Computational welding Simulations are not fully established as a science but almost sufficiently developed to be applied to various simplified problems in the heavy industry. The study has shown the advantage of using the inherent strain method for a welding simulation tool, for simple models which can be used as benchmarks.