A study of composite laminates failure using an anisotropic gradient-enhanced damage mean-field homogenization model

Abstract

The failure of carbon fiber reinforced epoxy laminates is studied using an anisotropic gradient-enhanced continuum damage model embedded in a mean-field homogenization scheme. In each ply, a homogenized material law is used to capture the intra-laminar failure. The anisotropy of the homogenized material model results from the homogenization method and from the reformulation of the non-local continuum damage theory to account for the material anisotropy. As a result the damage propagation direction in each ply is predicted with accuracy as compared to the experimental results, while the problems of losing uniqueness and strain localization, which occur in classical finite element simulations when strain softening of materials is involved, can be avoided. To model the delamination process, the hybrid discontinuous Galerkin/extrinsic cohesive law method is introduced at the ply interfaces. This hybrid method avoids the need to propagate topological changes in the mesh with the propagation of the delamination while it preserves the consistency and stability in the un-cracked interfaces. As a demonstration, open-hole coupons with different stacking sequences are studied numerically and experimentally. Both the intra-and inter-laminar failure patterns are shown to be well captured by the computational framework.

An incremental-secant mean-field homogenization method with second statistical moments for elasto-plastic composite materials

“…(103-104), the multi-scale numerical model does not lose the solution uniqueness upon strain-softening of the composite material, and the solution remains mesh-independent as demonstrated in [28,29]. As a result, macro-scale composite laminates can be studied using the non-local damage-enhanced MFH and the strain localisation can be captured in the different plies [29,53] lamination model as detailed in [53], allows modeling the failure of coupon tests. The configuration after total failure is illustrated for both the numerical (in which case damage reaches one) and experimental tests in Fig.…”

“…• As the residual stress is neglected in this formalism, the second statistical moment estimations of the von Mises predictor (35) and of the current yield stress (53), are assumed to read…”

A micromechanics‐based inverse study for stochastic order reduction of elastic UD fiber reinforced composites analyses

“…As an assumption, the microscale material properties are assumed not to suffer from uncertainties. A similar material system has been identified and used in the works of Wu et al, 25,38 in which the elastic properties of the matrix and fibers are as follows. GPa.…”

“…• For a given realization of C M with a known v I , we solve the optimization problem stated by Equations (34) and (38) to obtain the corresponding material parameters , ,Ê 0 , and̂0 of the M-T model.…”

“…Conducting multiscale simulations using the M-T model has several advantages, ie, the homogenized response of the composite material is obtained at a low computational cost even for nonlinear simulations; complicated anisotropic damage evolutions usually considered in the case of damage simulations are replaced by simple isotropic damage laws in the phases 37,38 ; and finally, although the detailed information provided by the full-field simulations is lost; a certain amount of qualitative information is kept by the micromechanics model in the sense of volume average. These advantages make the stochastic M-T model an efficient ROM to achieve a full process from microstructure analysis to statistical evaluation of composite structures.…”