Experimental verification of shear analogy approach to predict bending stiffness for softwood and hardwood cross-laminated timber panels

Abstract

Lower grade material of three previously untested species (Eastern White Pine, Red Maple, and White Ash) were fabricated in Cross Laminated Timber (CLT) panels and tested to determine their mechanical properties. The results were compared to the ANSI/APA PRG-320 production standard for CLT. Both of the hardwood species met requirements for the V2 species group, but the softwood species did not. Next, the bending stiffness results were compared to bending stiffness predictions from the Shear Analogy approach as described in the US CLT Handbook. The Shear Analogy approach underpredicted the bending stiffness of the softwood CLT by less than 5%, and underpredicted the bending stiffness of the hardwood CLTs by about 25%. The difference in the hardwood prediction was reduced to about 15% by using published elastic moduli ratios. Average hardwood elastic moduli ratios for use with the Shear Analogy Method were proposed.