The NHERI Lehigh Real-Time Cyber-Physical Systems Simulation Experimental Facility (EF) recently completed a series of large-scale tests on a 5-story mass timber structure. The test setup included a first-story subassembly comprised of a self-centering cross-laminated timber (CLT) rocking wall, floor diaphragm, gravity load system, and collector beams subjected to multi-directional loading. The experimental campaign featured monitoring of the rocking wall’s response using fiber optic sensors to measure shear and flexural wall deformations under bi-directional loading.
NHERI Lehigh collaborators from the Stevens Institute of Technology, Dr. Yi Bao and his students, installed fiber optic sensors on the CLT rocking wall. These sensors were used for structural monitoring and assessment of the response of the CLT rocking wall. The outcomes of this monitoring program are to study the shear and flexural wall deformations under bi-directional loading, and the long term creep performance of the wall. The results of the wall deformation monitoring will help engineers designing these walls understand the performance of the wall under natural hazard events. The results of the wall creep performance will help engineers understand the long term performance of the walls.
In addition, NHERI Lehigh collaborators from Southern Methodist University, Dr. Nicos Makris, and the University of Texas at Tyler, Dr. Kostas Kalfas, have performed tests at the NHERI Lehigh EF over the past few years studying the performance of pressurized sand dampers that they had developed. Dr. Liang Cao, NHERI Lehigh Research Scientist, designed the CLT rocking wall to couple it with the pressurized sand dampers for large-scale multi-directional seismic applications. These pressurized sand dampers were installed to dissipate energy in the CLT rocking wall when subjected to earthquake ground motion histories. The outcomes of these tests are to better understand the energy dissipation performance of these dampers when subjected to realistic, bi-directional loading. These outcomes will help to provide engineers interested in utilizing these dampers in a building with important data, and pave the way for technology transfer into industry.
The mass timber subassembly is a testbed with interchangeable components, making it an efficient and economical means to acquire data on response to bi-directional loading. This testbed is available to researchers and industry interested in conducting experiments on mass timber buildings. This collaborative research was partially funded by the operations and maintenance of the NHERI Lehigh EF sponsored by the National Science Foundation, and is located within the Advanced Technology for Large Structural Systems (ATLSS) Engineering Research Center.
This research builds upon previous work led by Dr. Alia Amer, Dr. Richard Sause, and Dr. James Ricles.