Failure criterion for adhesively bonded joints using Arcan?′s experimental method

摘要

Characterization of polymeric materials mechanical behavior requires some previous knowledge about their structure, which allows the choice of more appropriated models and methods. Polymeric materials, below their glass transition temperature (Tg), may be handled as perfect elastic solids, allowing the use of classic mechanics to characterize their behavior. Polymers above their Tg present a viscous contribution to mechanical behavior, which has to be taken into consideration by modeling it. Adhesively bonded joint, joining of different materials using a polymer as adhesive, adds to the mentioned requirements more parameters, such as surface roughness, adhesive thickness and different types of contributions to adhesively bonded joint strength. This work has the purpose of presenting a mechanical behavior characterization of adhesive bonded joints, concerning their average stress at rupture. A modified Arcan?′s device was used to obtain the average stress at rupture under different angles or loading conditions, such as pure shear 0?°, pure tensile strength 90?° and combined conditions. The experimental results were applied to a theoretical model, which takes into consideration the hydrostatic contribution to the mechanical behavior, called Drucker-Prager Model, which was initially developed to characterize soils.