Recent advancements on the phase field approach to brittle fracture for heterogeneous materials and structures

Abstract

Recent advancements on the variational approach to fracture for the prediction of complex crack patterns in heterogeneous materials and composite structures is herein proposed, as a result of the frontier research activities undertaken in the FP7 ERC Starting Grant project CA2PVM which focuses on the development of computational methods for the durability and the reliability assessment of photovoltaic laminates. From the methodological viewpoint, the phase field approach to describe the propagation of brittle fracture in the bulk has been coupled for the very first time with the cohesive zone model to depict interface crack growth events, for 2D isotropic and anisotropic constitutive laws, and also for 3D finite elasticity. After a summary of the key aspects underlying the theoretical formulation and the finite element implementation using a monolithic fully implicit solution scheme, an overview of the main technological applications involving layered shells, interface mechanical problems and polycrystalline materials is provided. The examples are selected to show the capability of the proposed approach to investigate complex phenomena such as crack deflection vs. crack penetration at an interface, intergranular vs. transgranular crack growth in polycrystals, and interlayer vs. translayer failure in laminates.

Phase‐field modeling of brittle fracture along the thickness direction of plates and shells

“…A comprehensive overview of the existing phase-field fracture formulations considering monotonic loads is presented in Reference 13, see also the references therein. Due to its diffuse modeling approach which has the advantage that no remeshing at discontinuities is necessary, the phase-field approach to fracture has been applied to a broad range of problems such as fracture including inelastic deformations, 14,15 viscoelastic materials, 16,17 interface failure, 18,19 heterogeneous materials, 20,21 dynamic loading, 22,23 fatigue failure, [24][25][26] or fracture with anisotropy. 27,28 The phase-field approach to fracture has been applied to plates and shells in many different ways, focusing on various aspects.…”

Comparison of peridynamic and phase-field models for dynamic brittle fracture in glassy materials

“…For brittle fracture, this regularization is obtained using a variational approach for the classical Griffith energy balance. The phase-field (damage) variable, introduced as an extra degree of freedom per node in a finite element (FE) discretization, allows one to approximate the fracture paths [34]. By solving an energy minimization problem, damage evolution (and implicitly, cracks) are modeled without the need for remeshing [34].…”

“…The phase-field (damage) variable, introduced as an extra degree of freedom per node in a finite element (FE) discretization, allows one to approximate the fracture paths [34]. By solving an energy minimization problem, damage evolution (and implicitly, cracks) are modeled without the need for remeshing [34]. Quasi-static simulations of brittle fracture with PFM have shown some excellent match with experiments [35,36], but also some crack features (in thermally driven cracks, for example) not seen experimentally [37].…”