Experimental investigation and seismic analysis of a novel self-centering piston-based bracing archetype with polyurethane cores. (15th May 2023)

• Record Type: Journal Article
• Authors: Issa, Anas; Rahgozar, Navid; Alam, M. Shahria
• Is Part Of: Engineering structures. Volume 283(2023)
• Publication Date: 2023-05-15
• Subjects: Piston-Based bracing -- Polyurethane cylindrical core -- Self-centering -- Experimental investigation -- Seismic analysis; 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.2023.115735
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: A novel Self-Centering Piston-Based Bracing Element with Polyurethane Cores (PBPCs) has been introduced. The general mechanics, analytical formulas, and preliminary design procedure of PBPCs are presented. The PBPC shows self-centering response with negligible deformations after consecutive displacement histories. Effects of pre-compression level, loading rate, and successive compression cycles on its flag-shaped response are evaluated. An increase in hysteretic damping ratios was obtained by reducing the pre-compression strain level. Abstract: This paper introduces a novel self-centering Piston-based Bracing with Polyurethane Cores (PBPC) as a passive seismic control device. Frames fitted with such bracing elements will be able to mitigate the loss of life, post-earthquake repair costs, and downtime recovery after a major seismic event. The proposed earthquake-resistant archetype integrates a steel shaft, steel tubes, and hollow and solid polyurethane (PU) cylindrical cores. The PU cylinders are activated using a bracing shaft and dissipate seismic energy with a self-centering response. A set of unidirectional cyclic tests were conducted on a scaled PBPC specimen to quantify the effects of pre-compression force level, loading rate, and past loading history. The pre-compressed force curtailed the undesirable viscoelastic deformation and the energy dissipation capacity of PU cores. The non– and pre-compressed PBPC elements exhibited large deformability and adequate energy dissipation; nonetheless, they recovered their initial conditions with stable flag-shaped hysteresis loops following successive compression cycles. Additionally, a new material model was developed in OpenSees software for PBPC and a comparative seismic analysis was conducted. The simulation outcomes supported by experimental data proved the efficiency of the frame fitted with PBPCs in mitigating damage compared with a buckling-restrained braced frame.