Measuring Methods for Three-Dimensional Residual Stresses with The Aid of Distribution Functions of Inherent Strain (Report II) : TL_yL_z-Method and T-Method for Measurement of 3-Dimensional Residual Stresses in Bead-on-plate Welds(Mechanics, Strength & Structural Design)
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A distribution function of inherent strains on long bead-on-plate welds, which has 3 unknown parameters for each inherent strain component, is proposed. With the aid of the proposed distribution function of inherent strains, the measurement of 3-dimensional residual stresses can be made with the following procedures: (1) 3 pieces of specimens T, L_y and L_z (named TL_yL_z-Method) are cut from the bead-on-plate weld and the inherent strain components are separated. (2) Measurements are performed on the specimens T, L_y and L_z. Then, the inherent strain zones and the 3 unknown parameters for each inherent strain component are estimated. (3) 3-dimensional residual stresses are computed by applying the inherent strains measured in step (2) in the original welded plate, whose stress is free. When inherent strain distributes through the entire thickness of plate, the 3-dimensional residual stresses can be measured only by slicing one piece of specimen T (named T-Method). To verify the TL_yL_z-Method and T-Method, numerical experiments and actual measurements were carried out respectively for mild steel and stainless steel bead-on-plate welds. The measured residual stresses by the new methods show very good accuracy compared with those computed by thermal elastic-plastic FEM analysis and direct measurements on the surfaces of the welded plate.
- Transactions of JWRI
Transactions of JWRI 23 (2), 239-247, 1994-12