The Strength of Metal Joints, Made with Synthetic Resins: A Study of the Influence of the Geometry of Lap Joints on their Strength

The use of synthetic resins as adhesives for metals or other non‐porous materials, in which there is increasing interest for structural and production reasons, imposes certain restrictions on the components bonded and the type of joint used. In the following paper the general points applicable to adhesive joints are first considered. A large number of strength measurements on simple light alloy lap joints made with ‘Araldite’ by the Eidg. Materialprüfungs und Versuchsanstalt (E.M.P.A.) are used to analyse the manner in which the breaking load under tensile shear loading depends on the geometry of the test specimen. It can be shown that in this special case, which is however of importance in practice, there is an optimum utilization both of the adhesive and of the metal, whose yield point determines the choice of sheet thickness and overlap. The use of synthetic resins as adhesives for metals and other non‐porous materials opens up numerous new developments and possibilities in a whole range of industries. Although comparatively new it has already found many practical applications which steadily increase.