GEOMETRICALLY NONLINEAR DISCRETE CRACK MODELING IN LAMINATED COMPOSITES

Abstract

The failure process of composites involves multiple damage mechanisms and modeling them faithfully is important to the design of composite structures. Floating node method is able to simulate matrix cracks explicitly and their interactions with delaminations. In this work, we first formulate a two-dimensional geometrically nonlinear floating node method and then extend it to three-dimensional applications, in which a discontinuous solid shell element is developed to alleviate locking problems. Fiber damage model is further integrated into this method for the prediction of the whole failure process. Typical failure patterns including the shear cracking and induced delaminations in composite beams, delamination shapes bounded by matrix cracks in composite plates under impact, brittle and push-out collapse modes of open-hole laminates under compression have been accurately predicted. Finally, as material properties may contain inherent statistical uncertainties, we develop computationally cheaper surrogate models to obtain stochastic structural responses.