A Continuum Damage Model for Fatigue and Its Integration Scheme

Abstract

The objective of this paper is to develop a continuum damage model for fatigue prediction. A viscodamage model, which can rigorously handle damage anisotropy, distinct tensile and compressive damage behavior, and damage deactivation, is developed to produce stress-dependent fatigue damage evolution. An affine formulation governing damage evolution, and a closed-form formulation of the constitutive relations is derived based on the viscodamage model. An adaptive stepsize control and cycle jump time integration scheme is proposed and implemented to improve the present model’s efficiency in cyclic loading conditions. Through uniaxial cyclic loading simulations, the present model and time integration scheme is found to be capable of reliably and efficiently producing cyclic damage evolution. This model can be further calibrated to facilitate both uniaxial and multiaxial fatigue analysis in composite materials.