Prediction of Residual Stresses in Welded T- and I-Joints Using Inherent Strains

Abstract

In order to develop a predicting method of residual stresses in fillet welded T- and I-joints, a concept of inherent strain, being regarded as a source of the residual stresses, was introduced. With the proposed method, the residual stress of an interested weldment may be predicted by performing an elastic analysis, in which the inherent strain is replaced to equivalent distributed loads. The inherent strain distributions in various welded T- and I-joints were investigated by numerical simulations. The results showed that the inherent strains distributing in flange side and in web side of the several joints are almost the same. The inherent strains vary not only with the average temperature rise due to welding, but with the geometric ratio of the joints. Being simplified by a trapezoid curve, the inherent strain distribution in a fillet weld was expressed by formulas, in which heat input, material properties, and geometric dimensions were taken into account. Welding residual stresses in T- and I-joints, predicted by the proposed method employing the derived formulas, were compared with those obtained by thermal elasto-plastic analysis, and good agreement was recognized. The validity of the proposed method was also confirmed by experiments.

Evaluation of residual stresses and strains using the Eigenstrain Reconstruction Method

“…This means that no residual stress arises within the component if there is no incompatible strain, even e.g. under a thermal cycle generating uniform heating (Yuan and Ueda, 1996). Therefore, we believe that the term inherent strain can be used interchangeably with the term eigenstrain.…”

Analysis of welding distortion due to narrow-gap welding of upper port plug

“…Ueda and co-workers [10,11] studied the characteristic distributions of inherent strains in butt, T and I joints, and employed them to predict welding residual stress.…”

“…For seeking practical methods to predict welding residual stress and residual distortion, many numerical simulation procedures [10][11][12][13][14] were developed in the past decades. Ueda and co-workers [10,11] studied the characteristic distributions of inherent strains in butt, T and I joints, and employed them to predict welding residual stress.…”

Influence of tacking sequence on residual stress and distortion of single sided fillet submerged arc welded joint

“…Hibbitt and Marcal (1973) developed a numerical model for the welding of a large structure by subsequent loading to the structure for high strength steels. Ueda and Yuan (1993), Yuan and Ueda (1996) studied the characteristic distributions of inherent strains in butt, T and I joints, and successfully employed them to predict welding residual stress. Teng et al (2001) had investigated the residual stresses and distortion of T joint fillet welds using two dimensional finite element analysis.…”