Initial Fatigue Life Estimation of Welded Structural Components

Abstract

Numerical modelling of welding process of two cylindrical tubes subjected to cyclic loads of constant amplitude is presented. For that purpose the Finite Element Method (FEM) was used for determination of thermo-mechanical behaviour and evaluation of welded joint residual stresses. In this investigation an efficient computation method for initial fatigue life estimation of welded structural components has been developed. Computation method with corresponding computation procedure is based on finite element numerical simulations of the thermal and stress analyses. As measure of fatigue resistance of welded structural elements, estimated values of low cycle fatigue life were used. Estimation of damages up to crack initiation in the welded joints of two cylindrical tubes was performed using SWT (Smith-Watson-Topper) relations. Present computation results are compared with corresponding experimental results of welded structural components. Obtained computation results of initial fatigue life estimation of welded structural element are in good agreement with experimental results.