Design and analysis of mechanically laminated timber beams using shear keys.

摘要

Small timber layers can be mechanically laminated into a larger timber cross-section using shear keys to prevent slip between the layers. These mechanically laminated beams are commonly referred to as keyed beams, and their use has a strong historical precedence. Current building codes and design standards do not provide adequate guidelines for the analysis and design of keyed beams.;This project examined the applicability of an interlayer slip model to predict the partially composite behavior of the keyed beams. Solutions to the interlayer slip model for common loading configurations were developed, as were stiffness parameters for the semi-rigid wooden shear keys used to provide composite action.;Small scale testing was conducted on the wooden shear key components to verify the stiffness parameters. Full-scale testing of yellow poplar keyed beams using white oak and Parallam PSL shear keys was also performed to verify the interlayer slip model's ability to predict the strength and stiffness of specific specimens. A comparison to historical keyed beam test data was also conducted.;The interlayer stiffness model, as well as the analytical shear key stiffness parameters, was able to accurately predict both the behavior for the full-scale keyed beams tested specifically for this research as well as the historic keyed beam behavior. Shear key configuration, moisture content, and clamping connector stiffness all played significant roles in the actual keyed beam stiffness.