A. Firstauthor, Ž. Božić, B.B. Thirdauthor 29th International Workshop on Computational Mechanics of Materials Dubrovnik, September 15-18, 2019 IWCMM29 THE EFFECT OF RESIDUAL STRESSES ON FATIGUE CRACK GROWTH IN WELDED STIFFENED PANELS A. Firstauthor, Ž. Božić, B.B. Thirdauthor University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Ivana Lučića 5, Zagreb, Croatia, zeljko.bozic@fsb.hr The crack growth rate in welded stiffened panels can be significantly affected by the residual stresses which are introduced by the welding process. Well known power law models were employed to simulate fatigue life for a welded stiffened panel specimen damaged with a central crack. Stress intensity factor values (SIF) were obtained in finite element (FE) analyses by a linear superposition of the SIF values due to the applied load and due to weld residual stresses. The FE models included idealized, rectangular or triangular, residual stress distribution profiles.   FE mesh of the stiffened panel specimen The stiffened panel specimen made of mild steel commonly used in ship structures and manufactured by electric arc welding processes, was subjected fatigue testing with constant amplitude loading until failure occurred. The Elber and Schijve power law models were employed to simulate fatigue life for the welded stiffened panel specimen, taking into account the effect of residual stresses introduced during the welding process. The FEM models included typical idealized residual stress distribution patterns such as rectangular and triangular distributions. Rectangular residual stress distribution Triangular residual stress distribution