Numerical and Experimental Study of Residual Stress in Welded Joints with and without Constraint

Abstract

The knowledge of the residual stresses generated on the welding processes implies special relevancy in welded structures and components, because during his service life they will be working at several loading conditions that associated to the pre-existing residual stresses fields they can lead to a catastrophic failure. In this context, the present work has the purpose to study the residual stresses field generated in joints welded by the FCAW (Flux Cored Arc Welding) process, of ASTM A 131 grade A steel, used in ship construction, by X-ray diffraction, using the sin²ψ technique. It was realized a comparative study of the changes in the stress fields when adopted restrictions in order to maintain the design of the joint, as such a numerical computational analysis by the finite element method, with the results of the experimental analysis. The majority of residual stresses results had demonstrated qualitative similarity in their nature between the model and the experimental work in the heat affected region and welded zone. The Vickers microhardness analysis and microstructural characterization by optical microscopy had complemented the present work.

Key-words:
Welding; Residual stresses; Constraint grades; X-ray diffraction; Finite element method