Mechanical characterization of a pre-fabricated connection system for cross laminated timber structures in seismic regions

This paper focuses on the point-to-point X-RAD connection system for the construction of cross laminated timber buildings in earthquake prone areas. Tests on X-RAD connectors subjected to shear-tension and shear-compression loading configurations are presented as supplement to the experimental data provided in previously published research. Tests aimed at characterizing the behavior of timber walls assembled with the system and loaded by lateral force are also reported. A capacity domain that allows for quick safety checks for any given load combination on the connector was derived from the experimental outcomes and is presented herein. An extremely simplified, yet effective numerical approach (the connector behavior is reproduced by 3-link elements) is proposed and compared with the experimental evidence. The 3-link model was able to reproduce with sufficient accuracy both, the elastic and post-elastic response of the walls. In the discussion section, particular attention is given to the system capability of dissipating energy and exhibiting ductile behavior.