Experimental and analytical studies of the fracture behaviour of engineering adhesives and adhesive joints under impact loading

Abstract

Modern structural adhesives are extensively used in the aerospace, automobile and other industries where the resistance to impact loading is of paramount importance. Impact testing of homogeneous materials where a notched specimen is subjected to a known impulse is well established. The object of such tests is usually to determine a parameter, such as the fracture energy, G_c, which characterises failure of the material and which is independent of the detailed geometry of the specimen. Such a parameter may then be readily used in material selection and design studies. The present paper first considers the impact fracture of “bulk” model engineering adhesives and, in particular, considers the possible dynamic effects which can arise during impact testing and lead to inaccurate values of the impact resistance of the material being measured.