Durability of Underwater-Made Butt Steel Adhesive Joints under Laboratory Conditions: Theoretical Model

Abstract

Epoxide resins are widely employed as adhesives and are being increasingly used in engineering industries. However, adhesively bonded components may suffer significant loss in strength when exposed to environmental attack. The most severe threat is water, and adhesive joint strength decay can be accelerated if externally applied stresses are present. In this work an attempt has been made to develop a model to predict the theoretical durability of butt mild steel joints made underwater. The model was based on experimentally obtained data using double-torsion underwater-made joints and ambient air-made double-torsion and butt joints. All joints were subjected to similar conditions, i.e., static stresses in the presence of water. The first step in developing a test method and model for predicting the environmental fracture data of butt joints made underwater has been proposed that was independent of the detailed butt joint geometry. The model appeared to be successful and accounted for the phenomenon of crack tip blunting that occurs in the adhesives. This is the first time such a model is reported in the literature that may be useful when all variables are included.