NUMERICAL MODELLING OF ROCKING CLT SHEARWALL CONSIDERING THE WALL-TO-FLOOR INTERACTIONS

The rocking behavior of cross-laminated timber (CLT) shearwalls is the primary kinematic motion that enhances energy dissipation in platform-type CLT building systems. During rocking, the vertical wall system inevitably interacts with horizontal floor system. At large lateral displacement, localized damage due to crushed fibers can occur to the rocking toe of wall and the face of floor This interaction affects the forces transferred to the connectors and subsequently influences the kinematic motion of the shearwall. However, many studies on the CLT shearwalls overlook the wall-to-floor interactions, either by treating shearwall as independent component of the seismic force resisting system or by employing a rigid diaphragm assumption. To achieve a realistic simulation of the rocking CLT shearwall, this paper first develops a beam-spring model that incorporates the nonlinear characteristics of connectors. The single- and coupledpanel wall models are validated against experimental results. To examine effects of different numerical representations of the wall-to-floor interactions, the beam-spring shearwall is integrated into a 3D model of a two-story conceptually designed coupled CLT shearwall system. Modal analysis has confirmed a reduced fundamental period of the shearwall system when adopting the rigid diaphragm. Furthermore, nonlinear dynamic analysis reveals significant differences in global lateral displacement and resistance, which can be attributed to the varying deformation demands, energy dissipation, and failure hierarchy of connectors.