Dynamic determination of the modulus of elasticity of maritime pine cross-laminated panels using vibration methods

This paper describes the preliminary results of an ongoing research activity involving Maritime Pine Cross-Laminated Timber (CLT) panels, aimed to exploit the potentialities of this native species of Sardinia. The modulus of elasticity (MOE) is a key parameter for grading wooden products and evaluating the overall mechanical properties of panels. Free Vibration tests can be an effective method to assess the dynamic MOE of wooden products; the method is based on the direct measurement of the first vibration mode frequency of the specimens and the indirect determination of the elastic parameters. The present work shows a straightforward approach to evaluate the dynamic MOE of cross-laminated panels by choosing suitable boundary conditions depending on the specimen sizes. For this purpose, various experimental tests were conducted on different configurations aiming to evaluate the dynamic MOE for the considered cases. Furthermore, the relationship between global vibrational behaviour of panels and original boards MOE has been investigated. The dynamic MOE obtained by vibration testing method has been compared with the static MOE evaluated by bending tests in order to find a correlation. A linear relationship between dynamic and static MOE was found, with the dynamic MOE being slightly higher than the static MOE, as expected. The dependence of the correlation upon the applied methodology was determined and regression equations were derived and are provided in the paper.