Behavior of cross-laminated timber diaphragm connections with self-tapping screws

Experimental and Numerical Characterization of Monotonic and Cyclic Performance of Cross-Laminated Timber Dowel-Type Connections

“…Cross-laminated timber (CLT) emerged for the first time in the early 1990s in Europe and afterwards gained its popularity all over the world as a structural component in residential and nonresidential buildings (Brandner et al 2016). During the last two decades, CLT has become more popular among structural engineers due to not only its suitability for low-rise and midrise buildings but also for its potential to be used in high-rise construction given that CLT has more strength, stiffness, and dimensional stability compared to conventional structural wood elements (e.g., lumber) (Sullivan et al 2018). In addition, CLT is an environmentally friendly, sustainable, cost-efficient, light-weight, and easy to assemble material compared to steel and concrete (Hossain et al 2016).…”

“…Ductile connections are needed to provide energy dissipation given the rigid structure of the CLT. Therefore, mechanical fasteners (nails and screws) have been widely used for CLT panel to CLT panel connections (Reynolds et al 2017;Ringhofer et al 2018;Sullivan et al 2018), while ductile dowel-type fasteners, used in brackets, (Popovski and Karacabeyli 2011) have also been used as seismic resistance connections.…”

“…The vast majority of studies have focused on hold down or bracket connections, which are mostly used in low-rise buildings (Flatscher et al 2014;Gavric et al 2011Gavric et al , 2015aLatour and Rizzano 2015;Mahdavifar et al 2018;Pozza et al 2018;Schneider et al 2013Schneider et al , 2015. Additional studies have investigated CLT shear connections such as SS, HL, BJ, and HL connections were found to exhibit a higher loading capacity and ductility compared to SS connections with the same fastener type, fastener spacing, and CLT species and layers (Sullivan et al 2018). Although change in fasteners configuration in shear connections in terms of inclination and spacing can increase stiffness or ductility, increase in both cannot happen simultaneously (Loss et al 2018).…”

“…Recent studies found that the National Design Standard (NDS) (AWC 2015) and European Code [EN1995-1-1 2004 (CEN 2004)] relations for estimating the capacity of SS and HL are conservative (in the case of HL they are highly conservative), which led to a safety factor higher than the target safety factor (Sullivan et al 2018).…”

In-plane elastic flexibility of cross laminated timber floor diaphragms

“…As is often the case in timber structures, strength and deformation characteristics of diaphragms are strongly dependent on connection behaviour. Typically, adjacent CLT panels at either wall-wall or wall-floor interfaces are connected by screws, and both loaddeformation behaviour and ultimate load capacity has been studied for various alignments of screw and panel [12,13,14,15,16]. Loss and Frangi [17] and Loss et al [18] investigate in-plane behavior of CLT floors in steel-timber hybrid structures through experimental tests on both connections and full diaphragms, and show significant contributions to deformation from steel-steel, steel-timber and timber-timber connections.…”