Analysis of a wooden specimen's mechanical properties through acoustic measurements in the very near field

Abstract

This paper presents the method for prediction of some basic mechanical parameters of a wood specimen by using simple instrumentation. The standard acoustic method for assessment of modulus of elasticity using the impulse excitation is extended by using a recording in the very near field. In this way, visualization of vibration patterns of the analyzed sample was accomplished for all modes below 5 kHz. This enables detection of signals with a good signal-to-noise ratio over a wide frequency range which is then used for loss factor assessment.