NON-DESTRUCTIVE ULTRASONIC TESTING METHOD FOR DETERMINING BENDING STRENGTH PROPERTIES OF GMELINA WOOD (<em>GMELINA</em> <em>ARBOREA</em>)

Abstract

Non-destructive ultrasonic testing method for determining bending strength properties of gmelina wood (Gmelina arborea). The objective of this study was to investigate the usefulness of non-destructive ultrasonic testing  method  in  evaluating  wood strength and stiffness of gmelina (Gmelina arborea) from several positions in the tree, both vertically and horizontally. These tests were conducted on 72 small  clear  wood  specimens  of dimensions  5 x  5  x  76 cm. The effects of position of specimen in a tree could be identified with ultrasonic wave velocity (Vus).  The dynamic testing determined by ultrasonic method, Vus and dynamic modulus  of  elasticity  (MOEd),  were highly correlated with the static bending test (static modulus of elasticity and modulus of  rupture). The developed regression models were significant. Ultrasonic method seems  applicable in situations where static bending test is not feasible.