Small-scale cross-laminated timber panels: bending performance through analytical, numerical, and experimental approaches

Abstract Cross-laminated timber (CLT) is an engineered wood product that has gained increasing attention in structural applications due to its sustainability and mechanical efficiency. In Brazil, however, experimental research on CLT remains limited, mainly because few laboratories are able to manufacture panels at the dimensions required by current testing standards. This study investigates the bending behavior of laboratory-scale CLT panels as a practical alternative for mechanical characterization and model validation. Small-scale CLT panels with three and five layers were manufactured using Pinus elliottii wood and a monocomponent polyurethane structural adhesive. Four-point bending tests were performed to obtain load–displacement responses, modulus of elasticity (MOE), modulus of rupture (MOR), and failure modes. In addition to the experimental investigation, the bending stiffness was evaluated using analytical models based on beam and laminate theories, and a three-dimensional finite element model was developed to numerically reproduce the experimental response. The three- and five-layer CLT panels achieved average MOE values of approximately 8.871 GPa and 6.977 GPa, respectively, while the corresponding average MOR values were 53.61 MPa and 42.89 MPa. Failure was predominantly brittle and initiated in the tensile layers. Comparisons between experimental results and analytical and numerical predictions showed consistent trends in bending stiffness and load–displacement behavior, with quantitative differences depending on the adopted modeling approach. The results indicate that laboratory-scale CLT panels can reproduce stiffness trends and dominant failure mechanisms reported for structurally sized CLT elements with comparable configurations, supporting their applicability for preliminary experimental and numerical investigations with reduced material and equipment demands.