Peridynamic Modeling of Toughening Enhancement in Unidirectional Fiber-Reinforced Composites with Micro-Cracks

Abstract

The matrix component of composite structures is generally brittle. In any damage occurrence, fracture propagates rapidly through the structure. This study proposes a novel toughening enhancement model for unidirectional (UD) composites to overcome these damage-propagation issues. The toughening mechanism is established by introducing the so-called micro defects/cracks for increasing the toughness of the matrix constituent of the composite structure. Mechanical simulations are performed utilizing a non-local continuum formulation known as Peridynamics (PD). The PD formulation facilitates modeling material discontinuities such as complex crack/ defect formations with arbitrary size, orientation, and location features in composite structures. Here, the toughening enhancement models are established by allocating various micro-crack formations in three different fiber orientations (0 degrees, 45 degrees, 90 degrees) of UD composite plates. The toughening effects of micro-crack clusters are thoroughly analyzed by making comprehensive comparisons of the propagation speed of an initially introduced macro-crack and its tip strain energy density. As a result, various micro-crack distributions are established to provide an augmented toughness to the brittle composite materials, and their key features are assessed in detail.