Modeling of fatigue damage evolution on the basis of the kinetic concept of strength

On the basis of the kinetic theory of strength, a new approach to the modeling of material degradation in cyclic loading has been suggested. Assuming that not stress changes, but acting stresses cause the damage growth in materials under fatigue conditions, we applied the kinetic theory of strength to model the material degradation. The damage growth per cycle, the effect of the loading frequency on the lifetime and on the stiffness reduction in composites were determined analytically. It has been shown that the number of cycles to failure increases almost linearly and the damage growth per cycle decreases with increasing the loading frequency.