Axial – Shear interaction on CLT hold-down connections – Experimental investigation. (1st April 2018)

• Record Type: Journal Article
• Authors: Pozza, Luca; Ferracuti, Barbara; Massari, Milena; Savoia, Marco
• Is Part Of: Engineering structures. Volume 160(2018)
• Page Start: 95
• Page End: 110
• Publication Date: 2018-04-01
• Subjects: CLT connection -- Hold-down -- Axial-shear interaction -- Coupled action; α slope of force-displacement branch between 0.1–0.4 Fmax according to EN 12512 -- β slope of hardening branch for EN 12512 – method "b" -- β* slope of hardening branch for EEH method -- µ ductility -- ρm mean wood density -- νeq equivalent hysteretic dissipation damping coefficient -- fh wood embedding strength -- fh_m mean value of wood embedding strength -- ftu_m mean value of ultimate tensile strength of nail -- Fax analytical axial withdrawal capacity of nail -- Fmax maximum force of connection from tests -- Fv analytical load-carrying capacity of the connection -- Fu ultimate force -- Fy yielding force -- ΔF strength degradation -- d nail diameter -- dFmax maximum force displacement for monotonic and cyclic experimental curves -- dFu ultimate displacement for monotonic and cyclic experimental curves -- dy yielding displacement for monotonic and cyclic experimental curves -- k1, k2, k3 elastic post elastic and softening branch stiffness of the tri-linear approximation -- kser initial stiffness for steel-to-timber connections according to Eurocode 5 -- kUL unloading stiffness from tests according to EN 26891 -- leff profiled length of the nail shank -- My fastener yielding moment -- My_m mean value of fastener yielding moment -- n number of nails -- Rv mean analytical load-carrying capacity of a single nail -- Rax mean "rope effect" capacity of a single nail -- t1 penetration depth of the nail; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2018.01.021
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Tension-shear interaction in hold-down was never investigated until now. Results from a specifically designed experimental campaign are presented. Experimental results has been analysed using specific linearization criteria. Results allow to outline tension – shear interaction in hold-down connections. Dissipative capacity of hold-down connection has been extensively investigated. Abstract: Nowadays, the design of CLT wall connections is based on the hypothesis that hold-down connections are subjected only to tension and angle-brackets only to shear. Nevertheless, experimental investigations on CLT walls under seismic action highlighted that hold-downs may be subjected also to significant lateral displacement, and then to a tension-shear coupled action. The aim of this work is to experimentally investigate the axial-shear interaction in typical hold-down connections. To this purpose, an extensive experimental campaign was conducted with a specific setup allowing to impose prescribed levels of lateral displacement and varying the axial displacement in a monotonic or cyclic way. The test results on 15 specimens are presented here and critically discussed in terms of load–displacement curves, strength, stiffness, energy dissipation, strength degradation and ductility. Moreover, two different approaches for the definition of the connection's yielding limit are used, according to a tri-linear approximation of the experimental load–displacement curve. Forces and stiffnesses provided by these methods are compared with those predicted by code provisions.