Experimental Investigation and Finite-Element Modeling of an Aluminum Energy Dissipater for Cross-Laminated Timber Walls under Reverse Cyclic Loading

Abstract

Cross-laminated timber (CLT) panels with unbonded post-tensioning and a rocking mechanism can be used as a robust lateral load–resisting system (LLRS). The seismic performance of these systems can be improved further by incorporating external sacrificial energy dissipating elements. The additional damping provided by the energy dissipaters reduces the structural displacement demand during a design-level earthquake, and the unbonded post-tensioning provides recentering ability. This study developed a surface mountable, easily replaceable sacrificial oval metallic element specific to the CLT walls using aluminum was. This connector contributes to the wall system lateral load capacity. Laboratory testing of the aluminum connectors under cyclic shear loading was performed to characterize the force–displacement behavior and energy dissipating capacity. A detailed three-dimensional (3D) finite-element analysis (FEA) of aluminum connectors was carried out to replicate the observed experimental behavior. The experimental results, analytical modeling, and design equations for connector force–displacement response based on first principles are presented in this paper. The test results showed that the O-connectors can be used as an effective energy-dissipating element with equivalent damping ratio varying between 20% and 40%. The simplified design equations calculated the response within 90% of the measured values.