Analysis of creep crack growth in bonded joints based on a Paris' law-like approach

Creep crack growth is one of the factors that could affect the durability of a bonded joint and compromise the safety of structures over long periods of time. However, numerical tools and test methods relating to creep crack growth in bonded joints are not widely available yet. In this work, a Creep Crack Growth Model (CCGM) is proposed for adhesively bonded joints. The model describes the relation between the crack growth rate and the energy release rate. The CCGM is fitted with results from Roller Wedge Driven creep crack growth (RWDC) tests and validated against the results obtained from tapered double cantilever beam (TDCB) tests with a constant load applied. Additionally, it is demonstrated that the proposed model can be introduced in a fatigue tool commercially available from the finite element method (FEM) code Abaqus to predict creep crack growth. The FEM results show that the phenomenological expression fitted from experimental tests results, which is used as input for the FEM tool, is reproduced with accuracy. Moreover, it is shown that the CCGM is capable of predicting creep crack growth rates when a different specimen geometry is used, thus demonstrating that the model correctly captures the physics of the problem.