Investigating De-Bonding Using an Impact Loaded Blister Test

This article delves into the critical issue of de-bonding in adhesively bonded systems under impact loading, focusing on the automotive industry's increasing adoption of adhesive joining methods. It extends the application of the Shaft Loaded Blister Test (SLBT) to create an Impact Loaded Blister Test (ILBT), designed to evaluate de-bonding under high loading rates. The study reviews existing literature on de-bonding under various loading rates and compares different testing methods such as the Double Cantilever Beam (DCB) and End Notched Flexure (ENF) tests. The ILBT involves a two-layer system of PMMA bonded to steel, subjected to impact loading using a polycarbonate loading bar. High-speed imaging captures the de-bonding process, while strain gauges and a high-speed camera synchronously record load, load-point displacement, and blister radius histories. The energy release rate (ERR) is calculated using a simplified axisymmetric analysis, and finite element simulations with embedded cohesive zone elements determine the traction-separation law parameters. The study highlights the ILBT's advantages over other tests, including the absence of edge effects and the ability to achieve high displacement rates. The results demonstrate the ILBT's potential for studying adhesive joint failures under impact-like conditions, making it a promising technique for further research in the field.