Assessment of defects and mechanical properties of wood members using ultrasonic frequency analysis

Recognizing the limited value of the results from ultrasonic time-of-flight measurements, this paper emphasizes wave attenuation measurement in the frequency domain. The influence of travel distance, moisture content, and the presence of defects on wave attenuation are investigated using fast Fourier transforms of received ultrasonic through transmission signals. Our research results have revealed that the frequency domain analysis can significantly increase the sensitivity of predictions of modulus of elasticity, and strength of clear and defective wood, under controlled laboratory conditions.