Table 1.

Properties of materials. The speed of sound in the longitudinal direction c and the mass density ρ were measured. Nominal values of the damping factor d (equal to tan δ for a loss angle of δ) were obtained from Green et al. (1999), Rosenhain 2003 and Ehsani et al. (2004). All measurements were taken at approximately 25°C. As with most timber species, P. radiata shows great variation in material properties (Green et al. 1999).

material	speed of sound c (m s−1)	density ρ (kg m−3)	damping factor d
aluminium	5040±103	2700±28	10−4
Pinus radiata	4930±100	420±30	10−2
EPDM rubber	45±1	504	10−1