How to find the perfect application pattern for adhesively bonded joints?

Abstract

Adhesive bonding has become increasingly popular in the manufacturing industry due to its many advantages. However, the need to completely fill the joint gap with adhesive for optimum force transfer remains a significant challenge. To ensure full gap filling and therefore joint integrity, safety critical applications often require the adhesive to flow beyond the bonded edges. Due to inadequate design of this process, the adhesive volume that escapes is often more than 30–50% of the adhesive volume. This current practice represents a suboptimal way of proceeding, which the current paper may mitigate.As a result, excessive amounts of adhesive are typically applied due to the lack of suitable models for predicting the flow and final distribution of the adhesive, including the excess amount. This limitation has hindered progress in adhesive bonding technology, and urgent action is needed to address this issue.This paper offers a solution to the significant challenge of predicting adhesive flow and distribution in manufacturing applications. The authors have developed and validated a model that allows the simulation of these complex processes. The paper goes further to present initial application patterns aimed at minimising adhesive waste while ensuring the full filling of the overlap. To achieve this, the authors employ a procedure that involves an advanced reverse squeeze flow simulation to derive an optimal application pattern from a simple initial design. It turns out that a wide range of different final distributions can be produced by a variety of initial star-shaped forms. This paper represents a significant contribution to adhesive bonding technology for anyone interested in manufacturing efficiency.

Keywords

• Adhesive bonding
• Joint gap
• Adhesive flow
• Reverse squeeze flow simulation
• Bonding optimisation
• Inverse modelling