Search

A method is developed to predict numerically the damage of composite laminates with more plies under low velocity impact loading. The Puck criterion for 3D stress states is adopted to model the intralaminar damage including matrix cracking and fiber breakage, and to obtain the orientation of the fracture plane due to matrix failure. According to interlaminar delamination mechanism, a new delamination criterion is proposed. The influence of transverse and through-thickness normal stress, interlaminar shear stress and damage conditions of adjacent plies on delamination is considered. In order to quickly and efficiently predict the impact-induced damage of composite laminates with more plies, an approach, which can predict the specific damage of several plies in a single solid element, is proposed by interpolation on the strains of element integration points. Moreover, the proposed model can predict specific failure modes. A good agreement between the predicted delamination shapes and sizes and the experimental results shows correctness of the developed numerical method for predicting low velocity impact damage on composite laminates. [ABSTRACT FROM AUTHOR]

In current design methodologies for composite aircraft structures, design parameters are considered as deterministic variables while their random are ignored. In fact, many parameters affect aircraft structures safety, and some of them have obvious random features which can not be ignored. Therefore a probabilistic design methodology must be developed with the consideration of main random variables. However, probabilistic design methodologies have been gradually developed and used for composite structure design. Six popular probabilistic design methodologies are discussed in details and their benefits and potential problems are summarized. Finally, the issues to be adressed are recognized in the probabilistic design of composite structures, which provides some helpful suggestions for further study. [ABSTRACT FROM AUTHOR]