A Continuum Damage Mechanics Model for Fiber Reinforced Composites

Abstract

Continuum damage mechanics has been proven to be a valuable tool for the determination of material deterioration of composites. Within this framework, a continuum damage model for determination of effective response of fiber reinforced composites is presented. It is assumed that damage evolves on planes with normal orthogonal to the fiber direction and thus is capable of describing the matrix dominated failure of composites. The approach is based on a tensorial representation of damage and on a coordinate-free determination of thermodynamic and dissipative potentials. To simplify the expression of the thermodynamic potential, certain damage tensor components are used to describe the initial material anisotropy. Furthermore, dissipative potentials are formulated which are assumed to be isotropic functions of the thermodynamic forces associated with damage tensors. Parameters for the CDM model are determined using a microscale homogenization method, in which a representative cell of the periodic microstructure consists of fibers, matrix, and two crack fields which are parallel to the fiber direction and evolve independently. The assumption of two independent crack fields in an initially transversely isotropic media makes the material behaviour monoclinic. A representative cell is discretized by the finite element method and the CDM model is fitted by the least squares method to the results obtained. It is concluded from the obtained results that the proposed damage model is capable of describing elastic properties of the damage material. Finally, the CDM model is implemented into the general purpose finite element program ABAQUS in order to capture the effective response of composites. The proposed approach is illustrated by simulating damage growth at the meso-level by calculating the response of a unidirectional laminate loaded in tension. The obtained results show that the essential aspects of the mechanical behaviour of a continuous fiber composite loaded in tension can be captured by the present damage model.

Continuum damage mechanics-based finite-volume homogenization of unidirectional elastoplastic fiber-reinforced composites

“…Due to the present emphasis on sustainability and efficiency in modern structural systems, damage evolution in heterogeneous media continues to garner a lot of attention. Microcracks, phase debonding, and separation are just a few of the local damage and failure processes that can occur in heterogeneous media with significant microstructure-induced stress fluctuations and gradients (Chen et al., 2021a; Isometsä and Sjölind, 1999; Marcin et al., 2010; Praud et al., 2020). Substantial efforts have been devoted to quantifying each of these damage types, their evolution with regard to load, strain, time, number of cycles, and other factors, as well as their impact on stiffness, nonlinear mechanical response, remaining life, and other factors.…”

“…In contrast with CZM, the CDM model takes into account different damage modes, such as matrix cracks and fiber-matrix debonding, based on the well-known principle of effective stress (Chatzigeorgiou et al., 2018; Isometsä and Sjölind, 1999; Krairi and Doghri, 2014; Lemaitre and Chaboche, 1994; Praud et al., 2017) by degrading the material moduli in terms of continuum damage scalar variable. Material strength or fracture mechanics failure criteria can be utilized to detect damage initiation.…”

Damage mechanism characterization of ±35° and ±55° FW composite tubes using acoustic emission method

“…For this purpose, the finite element (FE) analysis was used to enhance the accuracy of multiscale modeling (Jin et al., 2020; Wei et al., 2022; Wu et al., 2019). Furthermore, continuum damage mechanics (CDM) (Gao and Wang, 2021; Isometsä and Sjölind, 1999; Ribeiro et al., 2012) and micromechanical damage models (Liu et al., 2020; Zhu et al., 2021) have been used successfully. In order to identify the main types of damage in composite materials, i.e., fiber failure, transverse failure, fiber/matrix debonding, and delamination, the acoustic emission (AE) method is an effective technique (Pan et al., 2022).…”

On Continuum Damage Modeling of Fiber Reinforced Viscoelastic Composites with Microcracks in terms of Invariants

“…Continuum damage mechanics (CDM) has been proven to be a valuable tool for the determination of properties deterioration due to microcracks of composites. In continuum damage mechanics (CDM) models, families of damage are represented as continuous internal state variables, and concepts of irreversible thermodynamics are used in deriving constitutive equations [20]. A number of models of damage behavior of fiber reinforced composites are based on the methods of continuum damage mechanics (CDM).…”