Fracture mechanics-based method for prediction of safety factors of adhesive bondings

The increasing pressure on reducing costs has lead to light-metal designs which demand diverse joining techniques, such as adhesives, riveting, screwing and welding. Over the last years the adhesive joint technology has seen a significant increase in interest, due to remarkable advantages compared to other joining techniques. The growing usage of adhesive joints i.e. in the automotive industry also leads to increased demand for simulation methods for structure, crash and fatigue analyses of bonded components. The awakened interest is reflected by the growing number of CAE-based methods for durability designs of bonded components. The lecture introduces a fracture mechanics-based method to predict the durability of bonded metal components applying on the J-integral solution approach, which is implemented in the modern, process-oriented software nCode DesignLife of HBM. Inputs of the analysis are results of a standard FE solver, material fatigue data and cyclic loading. The energy release rate is determined at the crack tip, where a concentration of local plastic deformation is observed. Based on these conditions the line integral (J-integral approach) could be employ to the combination of adhesive and bonded metal components. In the conventional analytical way the combination can be regarded as a layered composite. The theoretical principles of the method were developed in a research project in UK.

 

The Author

Stephan Vervoort
Senior Application Engineer
Hottinger Baldwin Messtechnik GmbH
nCode Products