Quantifying the effect of profile design on flexural stiffness in cellular cross-laminated timber: a numerical exploration and experimental verification

The utilization of engineered wood products is becoming more and more important when it comes to carbon sequestration and sustainable building. Among them, Cross-laminated timber (CLT) has emerged as a popular mass timber product, offering enhanced structural properties and environmental benefits. This study investigates the potential of incorporating small-diameter trees as corrugated wood-strand composite panels into CLT, developing a cellular cross-laminated timber (CCLT). A systematic investigation was carried out to assess the impact of core geometry on the flexural stiffness of CCLT panels utilizing the finite element method. Six cases involving combinations of fixed and variable geometrical parameters were examined to determine the effect of each geometrical parameter. The findings revealed a substantial positive effect of corrugation depth, while bond length and unit cell length exhibited a negative influence on bending stiffness. Other geometric characteristics play a minor, supportive role. Considering the insights derived from the parametric study and considering manufacturing constraints, a corrugated geometry was designed and fabricated using an aluminum matched-die mold. The CCLT panels, constructed using these corrugated panels, were evaluated against predictions from a finite element model, demonstrating close agreement. Moreover, the CCLT exhibited a higher value of normalized modulus of elasticity by density compared to conventional CLT.