The invention discloses a
weld seam fatigue life calculation method based on
total strain energy density. The method mainly comprises the steps that 1, the weld-seam
total strain energy density, a life function equation and a fatigue strength coefficient, a fatigue strength index, a cyclic strengthening coefficient and a cyclic strain hardening index which are needed by half-cycle
life stress and a strain function equation are acquired through a welded joint fatigue test; 2, the
weld seam structure is simulated through a shell unit module, the stress-
strain response of the
weld seam structure under the cyclic load action is calculated through a multi-
load step method, and a stress-strain hysteretic curve is output; 3, the
total strain energy density is calculated according to the stress-
strain response, and the hot point fatigue life and a damage value of a weld
toe of the weld seam are calculated by combining the energy density with the life function equation. According to the method, contribution of elastic-plastic stress and strain to the
fatigue damage is comprehensively taken into account, scalar quantities are taken as damage parameters, the position and direction problems related to vectors are effectively avoided, the calculation precision is improved, and the time is saved.