Abstract
In this paper, a new method for the measurement of 3-dimensional residual stresses in fillet welds is developed using inherent strain, which is considered a source of residual stresses. As a procedure of the new method, firstly the inherent strains are determined from a few of measured elastic strains with the aid of a proposed inherent strain distribution function, then residual stresses are computed by performing elastic analysis when inherent strains are applied to the weld joints.
In the actual measurement, when three kinds of specimens T, Ly and Lz are cut from a fillet weld, the measuring method is called TLyLz-method ; when only one piece of specimen T is cut from the weld, the measuring method is called T-method.
Respectively using TLyLz-method and T-method, 3-dimenional residual stresses distributed on the transverse sections of a single-pass and a multipass T-type fillet welds are measured. The residual stresses measured by TLyLz-method and T-method show a good coincidence with the ones directly measured on the surfaces of the welded joints.
