Platelet critical length for Prepreg Platelet Molded Composites

Abstract

This work presents a comprehensive evaluation of platelet critical length in Prepreg Platelet Molded Composites (PPMCs), addressing the complex failure mechanisms in these material systems. An array of overlaid platelets is loaded under uniaxial tension while evaluating the failure mechanism as a function of platelet length. The research identifies two primary failure mechanisms: interface failure and platelet failure, which are distinctly dependent on platelet length. The transition between the dominant failure modes occurs at a critical platelet length, marking a critical juncture in the PPMC performance. This study offers insights into the stress transfer mechanisms within an array of platelets leading to failure. To evaluate the critical length, a continuum-based damage model for the platelets and a cohesive zone-based damage model for the platelet interfaces was implemented in a Finite Element Analysis (FEA) framework. The cohesive based interface allows for mode-I and mode-II failure types, with the approach being validated through benchmark studies of Double Cantilever Beam (DCB) and End-Noted Flexure (ENF) simulations. The central idea of the paper posits that the length of platelets impacts the mechanical properties and performance of PPMCs. It details the complex stress transfer mechanisms in PPMCs and their relation to the dominant failure mechanisms.