Characterisation and Simulation of Structural Adhesives

The analysis of adhesive bonded joints and structures relies on accurate materials data and mathematical models. In the present study the goal was to develop a method for simulating accurately, using LS-Dyna, the behaviour of aluminium structures bonded with a single part, heat curing epoxy adhesive. This required a structure with known boundary conditions and for which the substrates deformed in a predictable manner. A suitable specimen, formed from two folded aluminium tubes bonded into a T-shape, had been developed by Ford Research Center, Aachen. The MAT 169 material card was selected as a method that showed promise for use in the simulation of bonded joints. A test programme was developed to characterise the adhesive for use with the MAT 169 material card, using tests from the British Standards catalogue. These data were then used to analyse the T-shaped structure under quasi static loading. The results of tests and analysis of the T-shaped structures were used to assess the accuracy of the adhesive characterisation and suitability of the MAT 169 material card. A parametric study was then carried out to determine the robustness of the solutions. Once it had been established that a robust solution had been reached the results from the parametric study were used to develop an optimised set of input data for the adhesive.