Investigation on the Cyclic Response of Superelastic Shape Memory Alloy (SMA) Slit Damper Devices Simulated by Quasi-Static Finite Element (FE) Analyses

Abstract

In this paper, the superelastic shape memory alloy (SMA) slit damper system as an alternative design approach for steel structures is intended to be evaluated with respect to inelastic behavior simulated by refined finite element (FE) analyses. Although the steel slit dampers conventionally used for aseismic design are able to dissipate a considerable amount of energy generated by the plastic yielding of the base materials, large permanent deformation may occur in the entire structure. After strong seismic events, extra damage repair costs are required to restore the original configuration and to replace defective devices with new ones. Innovative slit dampers fabricated by superelastic SMAs that automatically recover their initial conditions only by the removal of stresses without heat treatment are introduced with a view toward mitigating the problem of permanent deformation. The cyclically tested FE models are calibrated to experimental results for the purpose of predicting accurate behavior. This study also focuses on the material constitutive model that is able to reproduce the inherent behavior of superelastic SMA materials by taking phase transformation between austenite and martensite into consideration. The responses of SMA slit dampers are compared to those of steel slit dampers. Axial stress and strain components are also investigated on the FE models under cyclic loading in an effort to validate the adequacy of FE modeling and then to compare between two slit damper systems. It can be shown that SMA slit dampers exhibit many structural advantages in terms of ultimate strength, moderate energy dissipation and recentering capability.

Finite Element Analysis for the Self-Loosening Behavior of the Bolted Joint with a Superelastic Shape Memory Alloy

“…Similar to the decrease of dissipation energy of a uniaxial cycle loading test, that of an SMA bolt also shows an obvious quick decrease to a stable value after a certain number of cycles. The remarkable decrease of dissipation energy means that the damping capability of superelastic NiTi SMA, which was also discussed in [ 46 ], degrades with the residual martensite accumulation and finally causes the functional failure of the NiTi SMA bolt.…”

11.55: Development of a 2‐dof model simulating the dynamic response of special truss moment frames with shape memory alloy bars as dissipation devices in the special segment

“…2. Schematic stress-strain curve of the superelastic effect of SMAs [11] Superelastic shape memory alloys have several advantages that make them ideal candidates for applications in seismic resistant design, such as large stiffness at large strains, re-centering capability, excellent fatigue and corrosion resistance, low elastic anisotropy and resistance to repeatable cyclic loading. The present paper, among other features, offers a constitutive model based on Graesser and Cozzarelli's model, which describes the behavior of superelastic NiTi SMA bars, accounting for their rate-dependent nature.…”

Constitutive modeling of cyclic behavior in shape memory alloys

“…: +98-34-31312406; Fax: +98-34-31312202; E-mail: r.mehrabi@vru.ac.ir subject of study in recent years (Saadat, Salichs et al 2002). Using the superelastic SMAs as a seismic damper allows researchers to investigate the effects of loading frequency and history dependent on the energy dissipation (Song, Ma et al 2006;Hu 2014). Some important characteristics of superelastic shape memory alloys such as hysteresis damping, excellent fatigue properties in cyclic loads, and strain hardening make them among the popular materials used in seismic resistant applications.…”