Comparative Composite Fatigue Damage Models for Life Prediction of Laminated Composite Structures

摘要

Two approaches have been compared in this paper for the failure prediction ofrncomposite laminate. The first approach is based on a progressive damage model, withrnthe application of LaRC04 as the damage initiation criterion and softening curves torndescribe damage evolution. Failure strain is calculated elementwise based on a meshrncharacteristic length in order to ensure its energy dissipation independence of the meshrnsize. The fatigue damage is evaluated based on stress states and S-N curves, which willrnbe added to the damage calculated from the static balance analysis. The secondrnapproach is a hybrid continuum damage and discrete crack representation of therncomposite matrix failure. While the fatigue damage is computed the same way as inrnthe first approach,, a phantom pair element technique is applied to explicitlyrncharacterize the matrix cracking induced displacement discontinuities but the fiberrnfailure is still simulated via a continuum damage approach. Also, the delamination inrnthe second approach is modeled through the element stiffness degradation.