Extended phase field modeling of interface debonding and bulk cracking in realistic 3D printed fiber reinforced composites

In this work, we shall implement a novel modeling approach to simulate interface debonding and bulk cracking in realistic 3D printed fiber reinforced composites. The materials are firstly manufactured with the Selective Laser Sintering of PA12 polymer powder embedding glass fibers and additive particles. An in-situ compression test on a cylindrical sample is conducted. X-ray Computed Tomography (XRCT) technique is employed to obtain experimental fracture images and to provide a complete 3D description of the morphology of each component for constructing a completely Realistic 3D microstructure mesh Model (R3M). Meanwhile, an Extended Phase Field Model (EPFM) is presented considering gradient plasticity and interfacial debonding mechanisms. Following that, numerical simulations are conducted, by using the EPFM and R3M, to investigate the fracture behavior in the fiber reinforced composite. In contrast to existing works, a qualitative comparison of fracture phenomena in experiments and simulations is conducted. Anisotropic behavior of the 3D printed fiber reinforced composite is observed both in the experiments and simulations. Our results reveal that the EPFM can well capture the experimental damage phenomena, including fiber/matrix debonding, fiber breaking and pore connecting in 3D printed fiber reinforced composites, by employing the R3M where the microstructure directly arises from the experimental XRCT.