Experimental evaluation of mechanical properties of softwood using acoustic methods

Abstract

This paper presents an evaluation of the acoustic ultrasound and stress wave methods for investigating the mechanical properties of wood and the factors that can affect the results, such as the type of device used, the wood species (Scots pine, Norway spruce, Silver fir), the cardinal direction relative to the direction of the plant growth, and the longitudinal measuring position in the trunk (the height of the trunk). The experiments were done using planks of selected species, with the aim of establishing the extent to which the values of the basic mechanical properties of wood could be predicted. These properties included compression strength parallel to the grain (MORL), modulus of elasticity in compression parallel to the grain (MOEL), modulus of elasticity perpendicular to the grain (MOER), compression strength perpendicular to the grain (MORR), hardness in the particular anatomical directions (HardR, HardT, and HardL), and density.