Development and experimental validation of self-centering buckling-restrained braces with shape memory alloy

Miller, David J.

Permalink

https://hdl.handle.net/2142/26052 Copy

Description

Title

Development and experimental validation of self-centering buckling-restrained braces with shape memory alloy

Author(s)

Miller, David J.

Issue Date

2011-08-25T22:11:00Z

Director of Research (if dissertation) or Advisor (if thesis)

Fahnestock, Larry A.

Department of Study

Civil & Environmental Eng

Discipline

Civil Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• steel frames
• seismic effects
• self-centering
• shape memory alloy
• energy dissipation
• residual drift
• performance-based design
• buckling-restrained braces

Abstract

Although conventional earthquake-resisting structural systems provide adequate life safety when properly designed, they often rely on significant structural damage to dissipate the seismic energy. The structural damage and the residual drift that may result from the inelastic response can make a building difficult, if not financially unreasonable, to repair after an earthquake. As a result, development of systems that return to their initial position (i.e., “self-center”) following an earthquake and minimize structural damage is a crucial need. The research presented in this thesis aims to address this need by creating an innovative self-centering brace for advanced seismic performance. In the present study, the seismic behavior and performance of self-centering buckling-restrained braces (SC-BRBs) using shape memory alloys (SMAs) is investigated. The SC-BRBs consist of a typical BRB component, which provides energy dissipation, and pre-tensioned superelastic NiTi shape memory alloy rods, which provide self-centering. The SMA rods are attached to the BRB portion of the brace using a set of concentric tubes and free-floating anchorage plates that cause the SMA rods to elongate when the brace is both in tension and compression. Using a five-story building as context, half-scale SC-BRBs are designed and fabricated for experimental validation. To characterize hysteretic response, the braces are subjected to a cyclic loading protocol adapted from the AISC Seismic Provisions for Structural Steel Buildings. The results of the experiments are used to validate an SC-BRB model in OpenSEES, which is used to conduct further parametric studies of SC-BRB behavior.

Graduation Semester

2011-08

Permalink

http://hdl.handle.net/2142/26052

Copyright and License Information

Copyright 2011 David J. Miller

Owning Collections