Bamboo lightweight shear walls: modeling and identification of sheathing-to-framing connections for seismic response analysis

The need for enhancing the sustainability of civil constructions has originated an increasing interest in the use of engineered bamboo-based products within the building sector. Nonetheless, while the static response of bamboo-made structures has been largely investigated, experimental and numerical researches concerning the response under dynamic loads are limited. Therefore, the present work deals with the assessment of the seismic behavior of modern bamboo lightweight shear walls, with focus on the energy dissipation ensured by sheathing-to-framing connections. Initially, a short discussion about architectural, sustainability and manufacturing issues related to the use of bamboo in modern civil constructions is provided. Then, the experimental cyclic response of fasteners employed within glued laminated bamboo (glubam) shear walls is simulated by using a suitable phenomenological model whose parameters are identified through a soft computing-based numerical technique. A parametric finite element model developed within OpenSees is thus employed to assess the global seismic response of the wall. A comparison between the response of glubam-and timber-based shear walls is finally provided. This highlights that the main parameter dictating their global behavior is the local non-linear behavior of the single fastener when the cross-section size of the framing elements allows the full exploitation of its capacity and plastic deformation. The numerical simulations well agree with the main evidence carried out from the available experimental data. Particularly, it is found that glubam lightweight shear walls usually exhibit larger capacity and reduced ductility with respect to equivalent timber walls.