Acoustic Analysis of Commercially Available Timber Species in Nigeria

Several acoustic techniques have been used to determine elastic and damping properties of trees, logs and beams\ud in different parts of the world but such acoustic data on timber are not available in standard form in Nigeria.\ud Ten species of locally occurring Nigerian timber (five hardwood species and five softwoods species) were\ud sampled and subjected to acoustic analysis using a „Portable Ultrasonic Non destructive Digital Indicating\ud Tester (PUNDIT), with a view to assessing the stiffness and strength characteristics of the timber species by\ud obtaining the velocity of ultrasonic longitudinal stress waves through the timber piece and hence calculating the\ud dynamic Modulus of Elasticity (MoE) of each species.\ud Results obtained showed that the velocity of acoustic waves through a timber piece and hence the dynamic\ud modulus of elasticity (MoE) of the piece is directly proportional to the strength of the wood. Of all the timber\ud species tested, the species with the highest MoE value (8.48GPa) was Mansonia (mansonia altissima) while that\ud with the lowest MoE value (1.64GPa) was Alstonia (alstonia booeneicongensis). This study thus provides for\ud the first time, valuable data on the strength characteristics of ten commercially available species of Nigerian\ud timber represented in terms of their dynamic MoE values