PHYSICAL AND MECHANICAL PROPERTIES OF SOME CHILEAN SOFTWOODS AND HARDWOODS USING ULTRASOUND

The non-destructive techniques are a very important tool in the process of wood characterization and evaluation. In this work, the objective is the evaluation of physical and mechanical properties of some native Chilean wood species by using the ultrasound techniques and their comparision with the results of typical mechanical tests. The selected woods were four hardwoods: tepa (Laureliopsis philipiana), olivillo (Aextoxicon punctatum), laurel (Laurelia sempervirens) and lenga (Nothofagus pumilio) and two softwoods: alerce (Fitzroya cupressoides) and manio (Podocarpus nubigena). The equipment used were two types of ultrasound generators: Steinkamp BP5 and Panametric Epoch XT. The results shown a higher anisotropy for hardwoods than for softwoods, and a relatively symmetry for transversal wave propagation velocities and for shear modulus of elasticity, along the principal directions of the tree. At the same time the mean values of Young modulus of elasticity (MOE) obtained by using the ultrasound equipments were a 25-47 % higher than the same modulus measured by mechanical tests.