Damage In Adhesive Layer Research Articles

Investigation of effective parameters on composite patch debonding under static and cyclic loading using cohesive elements

The major addressed issue in this paper is investigation of impressive parameters on initiation and propagation of debonding in the adhesive layer when it occurs concurrently with the growth of an initial crack in a single-side repaired aluminum panels by composite patches under cyclic loading. Using the softening behavior of thin layer solid like interface elements, debonding is modeled between the composite patch layer adjacent to the aluminum panel as a function of loading condition and stress field. A user element routine and two damage model routines were developed to include the interface element and to simulate the distribution of damage in adhesive layer under static and cyclic loading. Fatigue crack growth in aluminum panel was also modeled using a simple approach developed by the authors. It is shown that, it is possible to decrease the debonding propagation by implementing appropriate composite patch and adhesive dimensional and material properties.

Fatigue Debonding Analysis of Repaired Aluminium Panels by Composite Patch using Interface Elements

Repaired panels with composite patches subjected to fatigue loading may fail due to the progressive debonding between the composite patch and aluminium panel. The objective of this paper is to study the initiation and propagation of a possible fatigue debonding in the adhesive layer while the crack also growths in the panel for single-side repaired aluminium panels. For this purpose three dimensional finite elements method with a thin layer solid like interface element is employed. Fracture mechanics approach is used for the analysis of crack growth in aluminium panel and the interface elements with fatigue constitutive law for mixed mode debonding growth in the adhesive layer. A user element routine and a damage model material routine were developed to include the interface element and to simulate the initiation and propagation of damage in adhesive layer under cyclic loading. It is shown that, the debonding propagation and crack growth rate of the repaired panels depend on the composite patch material and interface bonding properties significantly. It is also shown that using of patch material with higher elastic module leads to the faster damage or debonding growth in the adhesive layer during the fatigue loading.