Cross-Laminated Timber Plates: Evaluation and Verification of Homogenized Elastic Properties

Cross-laminated solid wood panels are used in timber structures as load bearing plates and shear panels. Since timber is a relatively soft construction material, the design of such structures is driven by serviceability criteria. Therefore, accurate elastic properties are required. In this paper a fully automated procedure to determine global elastic properties of full-scale cross-laminated wood panels is developed. Experimental modal analysis is used to determine resonance frequencies and mode shapes of rectangular wooden specimens. An analytical model based on Reddy's higher order plate theory is applied to calculate natural frequencies and mode shapes numerically. Corresponding frequencies are allocated using the modal assurance criterion. All three shear moduli and the two in-plane stiffness moduli are identified successfully by minimizing the difference between measured and estimated resonance frequencies in a total least squares sense. By comparing resonance frequencies and additionally by a static bending experiment, it is shown that the global mechanical behavior of the specimen is accurately described using an orthotropic, homogenized, linear elastic material behavior.