Integrated computational framework for modeling chopped fiber composites at the mesoscale

A new microstructure reconstruction algorithm, fully integrated with a non-iterative meshing algorithm named CISAMR, is introduced for synthesizing finite element (FE) models of chopped fiber composite (CFC) microstructures. This automated computational framework enables generating densely-packed CFC microstructures with desired statistical descriptors such as the volume fraction, diameter distribution, and spatial arrangement of fibers. The reconstruction process involves two main phases, starting with a virtual packing algorithm relying on Non-Uniform Rational B-Splines (NURBS) representation of fiber centerlines to efficiently detect/eliminate overlapping fibers. An explicit dynamic FE compression simulation is then pursued to increase the fiber volume fraction by modeling them as rigid shells and taking into account contact forces between fibers during the simulation. The shape/location of fibers excessively close to domain boundaries or intersecting them at sharp angles are then slightly modified in the resulting microstructure to ensure the construction of a high-quality conforming mesh using parallel CISAMR. Several example problems are provided to show the ability of this modeling framework for synthesizing and simulating the linear elastic response of polymer matrix CFCs with embedded glass fibers. We also demonstrate the application of high-fidelity FE models generated using CISAMR for simulating the nonlinear failure response of such composites. (c) 2022 Elsevier B.V. All rights reserved.