Delamination propagation under cyclic loading. Delamination Behaviour of Composites, 485–513
Publisher SummaryThe increased use of advanced composite laminates in primary structures of commercial aircraft requires a thorough understanding of the inelastic response of composites under general loading conditions. One of the most relevant mechanisms that contribute to the loss of stiffness and to the structural collapse of composite structures is delamination. Besides degrading the structural integrity of composites, delamination is also difficult to detect using traditional non-destructive inspection methods. The majority of the analytical and experimental investigations of delamination have been focused on the study of delamination growth under quasi-static loads. However, under cyclic loading, delamination might grow up to a critical size for loads well below the critical load for quasi-static loading conditions. Currently, the design methodologies barely consider the possibility of interlaminar crack growth under fatigue loading, being more oriented to prevent fatigue damage by assuring that a stress or strain threshold for delamination onset is not exceeded. This approach is evolving towards more powerful physically based analyses implemented in advanced computational models. This is a result of the industrial interest to partially replace the experimental tests required to certify new composite components (qualification of materials, design allowables, sub-components and full components) by virtual (numerical) tools able to simulate the inelastic response of the composite materials up to structural failure.
انتشار delamination تحت بار چرخهای. delamination رفتار کامپوزیت ها، ۴۸۵ - ۴۸۵