MECHANICAL PROPERTIES AND FAILURE BEHAVIOUR OF YEW AND SPRUCE DETERMITED WITH A COMPACT TENSION TEST AND DIGITAL IMAGE CORRELATION

摘要

While the longitudinal mechanical behaviour of Common yew is relatively well known, only limited information is available about its behaviour when the load direction is oriented perpendicular to the grain. Thus in this study, a compact tension test was performed on small yew specimens (and on spruce as a reference species) for four different crack orientations. The experiment was supplemented by a digital image correlation system to analyse the strain in fracture process zones on the surface of the samples. Various relevant mechanical parameters (critical load, initial stiffness and fracture toughness) were determined and evaluated. Better mechanical properties were obtained for yew as a result of its higher raw density compared with spruce. Several further characteristics were interpreted against the background of structure-property relationships.