Study on welding residual stress redistribution of AH36 marine high strength steel considering the crack propagation

Abstract

Fatigue fracture is the main failure mode of ship structures. The redistribution of welding residual stresses during crack propagation has a great influence on fatigue life. In this paper, the welding residual stress redistribution law of AH36 marine high strength steel under crack propagation condition is studied. The initial welding residual stress is calculated by the finite element method. The life-death element method is used to study the redistribution of welding residual stress under the given crack size, and the results are compared with the calculation results of the welding residual stress redistribution formula proposed by Terada to verify the feasibility of the finite element method. On this basis, the redistribution of welding residual stresses in the crack propagation along the weld direction was studied, and the influence of crack propagation with different shapes on the redistribution of welding residual stresses was further studied and the redistribution of transverse welding residual stresses during crack propagation was obtained. The calculation method can lay the foundation for the prediction of structural fatigue crack propagation considering the welding residual stress redistribution in subsequent studies.