Effect of Adhesive Layer Thickness on the Shear Strength of Adhesively Bonded Steel Joints in Wet Environment

Abstract

The paper presents the static strength of adhesively bonded steel joints aged in deionized water at a temperature of 60°C for 15 days at various adhesive thicknesses from 0.1 mm to 0.5 mm. Water uptake and the bulk adhesive tensile properties after aged in the same environment as the joints were also presented. It has been shown that water diffusion into the adhesive is non Fickian. The absorbed water in the adhesive significantly decreases the mechanical properties and it affects the static strength of the bonded steel joints. The effect of water is shown to be significant when the adhesive thickness is thicker than 0.2 mm as the static strength decreases sharply. This information is useful when designing the adhesive joints using thick adhesive layer exposed in moist environment.