FINITE-ELEMENT ANALYSIS OF CRACK-GROWTH LIFE PREDICTION UNDER COMPLEXLOAD HISTORY

This paper presents an innovative methodology for predicting the remai ning crack growth life, To simulate the true load history effect, the present paper investigates the effect of various load sequences and th e crack closure model is used to consider the residual stress effect d uring fatigue crack growth. The stress-intensity factor, which is comp uted by a comprehensive finite element computer code, ABAQUS, is corre cted to an effective stress intensity factor when the crack closure mo del is considered. Using the Paris equation, the fatigue crack growth rate under different load sequences can be calculated. The crack growt h coefficient in the Paris equation, C, obtained from usually constant amplitude fatigue tests in which residual stress effects are not incl uded, has to be modified to C0 with the crack closure model using the present method. Also, the predicted results are compared with the expe rimental fatigue test results. The methodology has been proven to be v ery efficient and accurate.