3D assessing of decay in oak using nondestructive ultrasonic technique

The ultrasonic wave velocity was used to detect decay extent and depth. An oak block (15×20×30 cm) with local decay was inspected in three main directions (longitudinal, radial and tangential). Ultrasonic wave velocities in three axis of decayed oak were incorporated into contour and color gradient plots along the wood profile for three direction inspections using SigmaPlot software. The specimen was dissected to compare the predicted internal condition to the actual internal condition. The results showed that the predicted internal condition by ultrasonic technique is in good agreement with the actual internal condition. Decreasing of ultrasonic wave velocity depends on depth and different stages of decay.