PNNL

Abstract

Two key shortcomings of many current ultrasonic nondestructive evaluation (NDE) techniques for wood products are the reliance on empirical correlations and the neglect of valuable waveform information. This study examined the feasibility of using fundamental physical relationships along with advanced signal analysis to nondestructively evaluate elastic material properties in natural fiber-based composite panels. An ultrasonic tone burst system was used to excite and receive antisymmetric plate waves in a variety of fiber-based composite panels. Dispersion curves were constructed exhibiting the variation of antisymmetric phase velocity with frequency. Based on fundamental plate wave propagation theory, flexural and transverse shear rigidity values were obtained from the dispersion curves. Excellent agreement of was obtained between NDE and mechanical testing for most panels. This fundamental research advances the state-of-the-art of wood composite panel NDE by providing a more thorough understanding of plate wave propagation and presenting a technique for direct measurement of elastic material properties.