Prediction of Internal Shear Capacity of Sugi CLT Panels

Cross-laminated timber (CLT) panels consist of several layers of lumber stacked crosswise and glued together on their faces. CLT panels are excellently applicable for timber buildings as slabs for horizontal structural members. Live load and dead load on CLT panels cause internal shear stress. Distribution of internal shear stress in CLT panels is affected by the modulus of elasticity of parallel layers. Rolling shear stress occurs in cross layers under shear force applied to CLT panels. Generally rolling shear strength is lower than the shear strength parallel to the grain. Few data of rolling shear strength of lumber exist. Internal shear capacity of several types of CLT panels was predicted by calculating the distribution of internal shear stress from the experimental rolling shear strength of sugi lumber. To verify the calculated shear capacity of several types of CLT cross sections, asymmetric four-point bending tests were carried out. The experimental shear capacity was found to be 12% lower than the average value of the rolling shear strength model for the lumber of the shear zone and was 16% higher than the minimum value of rolling shear strength model.