Elastic constants of Pinus radiata D. Don by means of ultrasound transmission techniques.

This work consists in applying the crystals theory and mechanical waves propagation in wood. The wood when is considered as a body of orthotropic symmetry satisfies Hooke's law in it's tensor form. Therefore, from the dynamical point of view the elastic constant are expressed by means of Christoffel's equation and can be determined using the ultrasound wave propagation of different polarization through wood. To obtain the constants is necessary the measurement of longitudinal and shear waves in different directions. The experiment results show that in some cases the exact shear wave velocities are very difficult to measure due to waves superposition. In this work, the elastic constants (three moduli of elasticity and three shear moduli) Pinus radiata D. Don growing in Chile by ultrasound trasmission techniques are estimated.