Optimization of shape memory alloy braces for concentrically braced steel braced frames

Abstract

Expanding the use of smart braced frames to govern the seismic response of structures by providing ductility and elasticity has been hampered and delayed by cost indexes. The braces in frames comprise two segments of expensive shape memory alloys (SMAs) and high-strength steel with high stiffness. These smart materials can reduce seismic damage by providing stiffness, yielding, and phase shifting. In this study, the length of the SMA segments in three- and six-story frames (applied either at all floors or as part of a dual system) was increased to determine the optimal length at a constant period. Performance levels and fragility curves were obtained to evaluate the seismic behavior of the optimized frame. The response modification factor determined based on the static pushover, incremental nonlinear dynamic analysis, and linear dynamic analysis suggests the ductility and over-strength of the optimized frame. The probability of being in or exceeding each damage state was determined with a Monte Carlo analysis and was acceptable and in accordance with previous deterministic analysis results.

Structural Performance of Single and Double-Section CBF Braces with Different Lengths Under Cyclic Loading

“…Li et al [15] conducted the nonlinear dynamic analysis of the three-and six-story CBFs. Babaei and Zarfam [16] applied Shape Memory Alloys (SMA), which have super elastic and high damping characteristics, as the brace component to enhance CBF's performance. Panjaitan et al [17] studied three specimens of CBF braces, i.e., single braces (BR1), double braces with batten plates (BR2), and double braces with lacing (BR3).…”

A Comprehensive Evaluation of Tuned Vertical Isolation System for Seismic Risk Mitigation

“…In the realm of seismic behavior and risk assessment, providing second layer of control to the system also leads to a significant stride in addressing uncertainties inherent in seismic events (Karimi Ghaleh Jough & Ghasemzadeh, 2023). The dynamic and unpredictable nature of seismic behavior necessitates a nuanced understanding of uncertainties, a focal point explored in many researches (Babaei & Zarfam, 2019;Karimi Ghaleh Jough & Beheshti Aval, 2018;Karimi Ghaleh Jough & Şensoy, 2020;Karimi Ghaleh Jough et al, 2021;Dithurson et al 2023).…”