Analysis of the moisture effect on the mechanical behaviour of an adhesively bonded joint under proportional multi-axial loads

Abstract

International audienceThe objective of the study is to identify the 3D behaviour of an adhesive in an assembly, and to take into account the effect of ageing in a marine environment. To that end, three different tests were employed. Gravimetric analyses were used to determine the water diffusion kinetics in the adhesive. Bulk tensile tests were performed to highlight the effects of humid ageing on the adhesive behaviour. Modified Arcan tests were performed for several ageing times to obtain the experimental database which was necessary to identify constitutive models. A Mahnken–Schlimmer type model was determined for the unaged state according to a procedure developed in a previous study. This identification used inverse techniques. It was based on the unaged modified Arcan results and on a coupling between an optimisation routine and finite-element analysis. Then, a global inverse identification procedure was developed. Its aim was to relate the unaged parameters to the moisture concentration and overcome the difficulties usually associated with ageing of bonded assemblies in a humid environment: a non-uniformity of the stress state and a gradient of mechanical properties in the adhesive. This procedure was similar to the one used in the first part but needed modified Arcan results for several ageing times. It also required an initial assumption for the evolution of the Mahnken–Schlimmer parameters with the moisture concentration

Prediction of Mechanical Behaviour of a Bulk Epoxy Adhesive in a Marine Environment

“…Bordes et al [11] also describe a partially coupled approach to predict long term behaviour during immersion, while other recent work includes that of Arnaud et al [25], who applied a Mahnken-Schlimmer model [26] with parameters identified on unaged and aged Arcan specimens. Leger et al [27] have also studied coupling effects; they examined temperature/humidity equivalence in a highly filled adhesive and modelled the influence on mechanical behaviour.…”