Stochastic computational modeling of the fracturing behavior in discontinuous fiber composite structures

Abstract

In this study, we numerically investigate the mode I intra-laminar fracture and size effect of Discontinuous Fiber Composites (DFCs) as a function of the platelet sizes and the structure thicknesses. First, the complex 3D mesostructures of DFCs are generated using a random platelet generation algorithm. The algorithm explicitly generates stacks of platelets into pre-defined partitions. Each partition stores unique platelet orientation and associated thickness. The partitioned morphology is transferred to a Finite Element (FE) model. The in-plane damage mechanisms are captured by a quasibrittle failure criterion whereas the out-of-plane inter-platelet damage is captured by cohesive elements. The stochastic FE model is calibrated using size effect experiments of a single platelet size and thickness. After the calibration, the model captures the effects of different platelet sizes as well as the change in thickness. Additionally, the model provides unique insights on the change in damage mechanisms of DFCs with respect to the platelet morphology. By simulating different mesostructures, we can further extend the effects of platelet sizes and the thicknesses beyond the experimental results.