Adaptive hierarchical enrichment for delamination fracture using a decohesive zone model

Abstract

SUMMARYThe paper describes a method for modelling delamination in ÿbre-reinforced composite structures with the aid of a decohesive zone model and interface elements. Unless a ÿne mesh is provided, the resulting load=de ection responses are very non-smooth and the iterative non-linear solution procedure may fail. To overcome this problem, the elements around the softening process zone are enriched with hierarchical polynomial functions. The enriched zones change as the analysis proceeds and the cracks propagate. This procedure is implemented using a technique which continually modiÿes the boundary conditions.

A Survey of Computational Models for Adhesion

“…Even when there is no physical instability present, the corresponding computational formulation can still become unstable if the FE discretization Survey of Computational Adhesion 97 is too coarse [129,130]. Essentially, the FE discretization needs to be sufficiently fine in order to capture the separation law properly.…”

“…Essentially, the FE discretization needs to be sufficiently fine in order to capture the separation law properly. An efficient way to achieve this, is to enrich the surface discretization such as is considered by [129,131,132,130,133,134,135,136]. It is useful to classify interface models according to the following four sections:…”

Enriched contact finite elements for stable peeling computations

“…(2) If one body is rigid, the sum and index k are dropped; this is considered in the following FE description. (3) In Equation (5), the first term is written as an integral over the current configuration of the bodies, B k , while the second term is written as an integral of the reference configuration of the bodies B 0k .…”

“…There is also a standardized peeling test used to analyze the properties of adhesives and adherents. Peeling is often compared to fracturing and therefore finite element (FE)-based cohesive fracture models are often considered in peeling computations [1][2][3][4]. A challenge in the computation of peeling problems are the large peeling stresses that can occur in a very narrow zone at the peeling front.…”

An enriched cohesive zone model for delamination in brittle interfaces

“…Elimination or at least reduction of the oscillations observed in the global load-displacement behavior of systems involving brittle interfaces without mesh refinement, will enhance the efficiency and robustness of CZMs. Local enrichment of the elements in the vicinity of the softening process zone with hierarchical polynomial shape functions is considered a means to reduce these oscillations [34].…”