Due to the extensive use of adhesive materials in structural bonding on one hand and the lack of a unified design tool for failure prediction in such structures on the other hand, development of failure prediction techniques has received much interest in recent years. A series of rupture elements have been developed and used to representing the process of failure initiation and propagation in elastic and elasto-plastic continua. The rupture elements form a line of crack bridging elements along the assumed crack extension path and are integrated into a 2-D finite element model. The user-defined elements are incorporated into the analysis using subroutine UEL called by ABAQUS finite element commercial code. Pre-cracked compact tension, C(T), specimens of bulk adhesive E27 and double cantilever beam, DCB, specimens with Aluminium substrates and a 1mm thick adhesive E27 binding layer have been used in an extensive fracture testing programme and the results are used to validate the predictive models. The proposed models are then discussed in the framework of conventional fracture mechanics and compared with the well-established linear elastic fracture mechanics (LEFM) and elasto-plastic or “non-linear” fracture mechanics (NLFM) procedures.

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