Relationship between density and ultrasonic velocity in Brazilian tropical woods

In this study, the effect of density on the velocity of an ultrasonic wave in wood is investigated. The aim of the present study was to analyze the influence of density on the longitudinal velocity of an ultrasonic wave, propagated in the longitudinal direction. Experiments were conducted on 5 cm × 5 cm × 5 cm wood specimens selected from the following species: pinus caribea (Pinus caribea var. caribea), eucalyptus citriodora (Eucalyptus citriodora), eucalyptus grandis (Eucalyptus grandis), cupiúba (Goupia glabra) and jatobá (Hymenaea sp.). The relationship between density and velocity was analyzed in two different manners: between and within species. The results obtained between species indicated that ultrasonic velocity tends to increase with increasing density. The results obtained within species also showed an increasing trend in ultrasonic velocity as density increased, but the relationship was not as significant as it was for between species.