Non-destructive testing of wood defects for Korean pine in northeast China based on ultrasonic technology

The wood samples were tested by the technique of ultrasonic, and the testing results were analyzed by using the statistic software of SPSS. The results showed that the length, density and knots of wood, the sizes of holes and numbers of holes have significant influence on propagation parameters and dynamic modulus of elasticity. If there are holes in the propagation path, the propagation time will be longer, and the propagation velocity and wood modulus will decrease accordingly. The studying results of this paper will provide a sound background for the application of ultrasonic technique in detecting the inner defects of wood products and other wooden structures, and also offer important reference for testing the inner defects of old trees and ancient buildings.