Notch Effects on the Fracture Behaviour of Orthotropic Materials

Abstract

During the last fifty years, composite materials have known a large development in the range of aeronautics and space. To make use of these materials, it has been necessary to consider the different joining techniques. When using fasteners such as pins or bolts, it requires holes and notches, which are sources of stress concentration. Of course, gluing techniques are more convenient, if applicable, but stress concentration is still present at the bond line toe. As a matter of fact, all these problems are also present in timber structures, where joining techniques mainly need holes and notches. This work presents the notch effect in orthotropic materials, with a special application to timber. Experimental work and finite element calculations are reported, showing a strong effect of the orthotropy of the mechanical properties on the stress gradient.