Experimental and analytical study of Friction Connection for seismic retrofit with Cross‐Laminated Timber (CLT) panels

Abstract

Within the European project e-SAFE (Energy and Seismic AFfordable rEnovation solutions), this paper presents the experimental tests and modeling attempts for a class of Asymmetric Friction Connections (AFCs) tested in the laboratories of the Norwegian University of Life Sciences. The AFCs are part of the seismic retrofitting solution, called e-CLT, based on installing Cross-Laminated Timber (CLT) panels in reinforced concrete structures using friction connections. The authors carried out experimental tests on AFCs fixed with screws to a CLT panel to observe the contribution of timber to the total dissipation performance. The investigation is based on 20 cyclic test data with two different setups. The main one includes a CLT panel and screw connection, while the second one isolates the friction behaviour to evaluate the influence of the screw connection. A modified LuGre hysteresis model for friction is developed to simulate the experimental cyclic response of the tested specimen. The model possesses a direct physical meaning, and it explicitly depends on the slip force and the pre-slip stiffness.The optimized model is used to assess the performance of the AFC by varying the pre-slip stiffness and the slip force.

Cyclic Tests on an Innovative Friction Dissipative Device for Seismic Retrofit With CLT Panels

“…This section will give a brief overview of the experimental results; the complete outcome is presented in [8]. Figures 9 to 12 show results of the tests in term of forcedisplacement graphs.…”

“…In this prototype the free profile is composed of two separate pieces, connected by lateral bolts in elongated holes, which offer the additional benefit of vertical adjustability in the mounting phase [6], [7]. The third phase of testing, addressed in this paper, used a design called HYB (hybrid), which attempts to keep the positive aspects of STD and ALT: front mounting possibility and more straightforward L shape [8]. The HYB specimen, seen in Fig.…”

“…Figure 13: Scheme illustrating how the addition of more components to the friction connection influences the behaviour: a)single ideal friction connection; b)specimens tested on the steel setup in[5],[8]; c) specimens tested on the CLT setup in[8].…”

Mechanical Properties of Improved Multiple-Layers Viscoelastic Damper

“…Passive control systems are known as one of the most preferable solutions due to their advantages such as no need of electrical energy to work, simple design, construction, maintenance, easy installation, and low cost [9,10]. Viscoelastic dampers (VEDs) are very popular among passive energy dissipation devices.…”