Study of Brazilian native wood 'Caryocar villosum' rolling shear properties to produce CLT panels.

Abstract

The utilization of Cross-Laminated Timber (CLT) in construction has surged for its sustainable nature and structural efficiency. However, existing research predominantly focuses on CLT production using softwood species, neglecting the potential of utilizing hardwoods. This study investigated rolling shear strength (f_rs) and stiffness (G_rs) 3-layer CLT elements made from Pequiá ("Caryocar villosum"). Experimental shear (vertical and inclined) and bending tests were conducted on different samples of specimens. Complementing the experimental work, numerical simulations using ABAQUS software were employed. Results indicated similar average resistances (f_rs) across different tests. The higher average stiffness (G_rs) was observed in vertical shear compared to inclined shear tests. The vertical shear test was deemed more suitable for determining stiffness. Furthermore, the panel’s average stiffness was found to be greater than the beam’s average stiffness. An analytical equation was developed for the three-layer panel, and it was effective in estimating the rolling shear stiffness from bending tests. Additionally, numerical modeling successfully identified the regions of highest stress concentration, where ruptures occurred in the samples tested experimentally. These ruptures mainly occurred due to the concentration of shear stresses in the central layer of the CLT samples, with the contribution of normal compression and tensile stresses.