MOISTURE DURABILITY PREDICTION OF ADHESIVELY BONDED JOINTS USING ACRYLIC ADHESIVES

摘要

Adhesives are increasingly being used in structural engineering applications, but a problem frequently encountered is that the mechanical properties of bonded joints, may rapidly deteriorate upon exposure of the joint to aggressive environmental conditions involving heat and humidity. Moisture durability is one of the most important factors of the reliability of adhesively bonded structure. Moisture diffusion to adhesive layer can be calculated by Fick's diffusion law. However, the relationship between the adhesive strength and calculated moisture distribution is not cleared. In this study, the finite element method (FEM) was applied to acrylic adhesive layer of the tensile butt joints that was tested by humidity exposure for 5 days in 90% relative humidity at 80C. The time dependent distribution of moisture in adhesive layer was calculated. Analytical moisture content distribution was compared with failure mode of butt joints.