DESIGN OF SINGLE LAP JOINTS WITH MILD STEEL ADHERENDS

Abstract

Adhesively bonded single lap joints are a candidate structure fastening technique to riveted, welded and bolted joints, attaining a better load transfer and more uniform stress distributions. It is quite important to establish a relationship between static strength of a single lap joint and design parameters such as geometrical parameters, material response, type of loading and etc. This paper presents a conceptual design methodology for single lap joints with mild steel adherend S255 considering geometrical and material parameters. In order to perform this task, ductile (Veropal Super HE-20) and brittle (Carboresin) two component structural epoxy adhesives are implemented to examine influence of material behavior. Single lap joints are manufactured at various overlap lengths and undergone simple uni-axial tensile tests to identify static tensile strengths. Then a numerical model is created in a commercial finite element package program (ABAQUS™) to make a comparison between experimental and numerical failure loads, which implements well-known maximum value criteria for both adhesive and adherend failure. The results express that the material response and overlap length plays a substantial role in the design stage of bonded structures up to a certain point. Consequently, strength of a single lap joint is no longer dependent on increase of overlap length at which the failure mechanism is dictated by adherend yielding.