Reliability of a dual-curable adhesive bond

Abstract

This project aims at evaluating the reliability of a dual-curable adhesive bonded joint used in optical applications. The delamination at the interface adhesive-substrate is one of the most critical failure modes: once a crack is initiated, it propagates catastrophically even at small loads. The fracture toughness is tested statically and cyclically using state of the art methods. In addition, the use of an electrodynamic shaker to increase the collected data is analyzed: testing on the shaker permits testing several samples at a time and is a flexible tool to vary the applied load and frequency. An accurate determination of the material properties and the curing mechanisms is necessary to transfer load capacity values into strength values. It has been shown that the adhesive can be considered as linear visco-elastic up to 10% of the maximum strain. The samples for the shaker can be manufactured reproducibly and a first test gives promising results for the application of this instrument for the study of crack initiation and propagation on several geometries.