Methods for Residual Life Estimation of Welded Joints

摘要

A calculational model to solve the problems about welded joints life has been formulated in this paper. A welded joint in this model is considered to be an inhomogeneous as to its physical-mechanical properties deformed solid with a lack of fusion, which develops under cyclic loading. An equation for determining the fatigue crack growth rate was obtained from the energy balance of fatigue fracture of a joint inhomogeneous material and reversible elastic-plastic fracture of the process zone at this defect tip. A direction of crack propagation with respect to the initial defect location plane is determined from the condition that this direction provides the maximum crack growth rate. The proposed model has been used to evaluate the residual life of butt- and T-joints and a good agreement of the calculation and experimental data has been shown.