Displacement-Based Seismic Design and Assessment of Friction-Dissipating Light-Timber Frames Coupled with a Self-Centering CLT Wall

Abstract

A dual structural system for low-to-medium-rise buildings is examined, comprising light-timber frames (LTF) coupled with a cross-laminated timber (CLT) wall. To enhance the energy-dissipating capacity of LTF featuring pinching behavior, friction sheathing-to-frame connections have been proposed in place of conventional nail connectors. The resulting friction LTFs (FLTF) exhibit sustainably rich hysteresis loops that significantly enhance energy dissipation capacity. Nevertheless, the friction-dissipating mechanism leads to nonuniform story drift distributions and residual drifts in multistory FLTF buildings. To address this issue, a CLT wall with self-centering hold-down connections is coupled to the multistory FLTF building for imposing uniform story drifts and for reducing residual drifts. A direct displacement-based design (DDBD) approach is employed to design the dual CLT-FLTF system and ensure (i.e., impose) uniform seismic demand across the height of the building. Nonlinear-time-history analysis (NTHA) and incremental dynamic analysis (IDA) show that the DDBD approach can lead to safe designs and effectively control the displacements of the proposed dual system.