An anisotropic large displacement cohesive zone model for fibrillar and crazing interfaces

Abstract

a b s t r a c tA new cohesive zone model to describe fracture of interfaces with a microstructurs made of fibrils with statistically distributed in-plane and out-of-plane orientations is proposed. The elementary forcedisplacement relation of each fibril is considered to obey the peeling theory of a tape, although other refined constitutive relations could be invoked for the adhesive constitutive response without any lack of generality. The proposed consistent 2D and 3D interface finite element formulations for large displacements account for both the mechanical and the geometrical tangent stiffness matrices, required for implicit solution schemes. After a preliminary discussion on model parameters identification, it is shown that by tailoring the spatial density of fibrils at different orientations can be a way to realize innovative interfaces enhancing adhesion or decohesion, depending on the need. For instance, it can be possible to realize microstructured adhesives to facilitate debonding of the glass cover in photovoltaic modules to simplify recycling purposes. Moreover, the use of probability distribution functions describing the density of fibrils at different orientations is a very effective approach for modeling the anisotropy in the mechanical bonding between paper tissues and for simulating the complex process of crazing in amorphous polymers.

Revisiting the problem of a crack impinging on an interface:A modeling framework for the interaction between the phase field approach for brittle fracture and the interface cohesive zone model

“…In addition to the previous considerations, the development of numerical methods (especially finite element (FE)-based formulations) to predict fracture onset, propagation and branching in engineering components has been a matter of intensive research during the last decades, to tackle problems that cannot be solved by analytical methods. Most of the extensively used techniques to trigger quasi-brittle and ductile fracture events fall into the following general categories: (i) Continuum Damage Mechanics (CDM) models accounting for a smeared crack representation [19], which in their local version suffer from mesh dependency that has been partially alleviated by using integral-based non-local and gradient enhanced procedures [20,21,22,23,24]; (ii) extended FE strategies with nodal kinematic enrichment (extended-FEM, X-FEM) that rely on Partition of Unity Methods (PUM) [25,26,27] and element enrichment formulations (enhanced-FEM, E-FEM) [28,29,30,31]; (iii) adaptive insertion of cohesive interface elements during the computation or their prior embedding along all the finite element edges [32,33,34,35,36,37,38]; (iv) thick-level set approaches [39,40]. Although these strategies have been successfully applied to many different fracture mechanics problems, they all present limitations with regard to predicting crack initiation, crack branching, and crack coalescence for multiple fronts.…”

Crack Patterns in Heterogenous Rocks Using a Combined Phase Field-Cohesive Interface Modeling Approach: A Numerical Study

“…where N is a matrix including the element shape functions of the displacement field andB d = NL stands for the compatibility operator of the displacement field associated with the interface. The transformation of the global gap vector into the local setting referred to the interface [38,41] is conducted via the rotation matrix R from Equation (35) leading to the local gap vector g loc , given by:…”

“…Adaptive insertion of interface-like cohesive elements within the delimiting edges of the existing mesh, using extrinsic or intrinsic representations of the cohesive law [35][36][37][38][39][40][41].…”

A variational approach with embedded roughness for adhesive contact problems

“…At the interface, we assume to have conforming finite element discretizations for the continua in terms of the interpolation of the displacement field and the spatial discretization scheme. Consequently, we can introduce a special interface finite element with eMbedded Profile for Joint Roughness (MPJR interface finite element) whose kinematics departs from the formulation of interface elements used in nonlinear fracture mechanics for cohesive crack growth (Ortiz and Pandolfi, 1999;Wriggers, 2011, 2012;Reinoso and Paggi, 2014;Paggi and Reinoso, 2015), and it is further specialized for the present contact/adhesive problem with a non-planar interface.…”