Cyclic tensile of refurbish NiTi reinforcement bar for seismic mitigation

1st International Postgraduate Conference on Mechanical Engineering

工业技术（总论）;机械制造

Hamid, Nubailah Abd^1 ; Adnan, Azlan^2

Faculty of Civil Engineering, Department of Civil Engineering, Universiti Teknologi Mara, Shah Alam

40450, Malaysia^1

Faculty of Civil Engineering, Department of Civil Engineering, Universiti Teknologi Malaysia, Universiti Teknologi, Skudai

81310, Malaysia^2

关键词: Hysteretic behavior;    Inelastic deformation;    Low energy dissipations;    Martensite phase transformation;    Mechanical properties at ambient temperature;    NiTi shape memory alloys;    Permanent deformations;    Seismic resistant design;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/469/1/012118/pdf
DOI  :  10.1088/1757-899X/469/1/012118

学科分类：工业工程学

来源: IOP

【 摘 要 】

This research highlighting the novel properties of pseudo-elastic Ni-Ti bar owing to their ability to reverse macroscopically inelastic deformation during earthquake known as recentering capability and large elastic strain capacity which originated from the reversible austenite to martensite phase transformation. Hence, this paper presented and evaluates the cyclic properties of pseudo elastic Ni-Ti shape memory alloys to assess their prospective use for seismic applications to be exploited as seismic resistant design and retrofit. In addition, the correlation of hysteretic behavior of Ni-Ti alloy in terms of cyclic loading number and history, mechanical properties at ambient temperature, equivalent damping, energy dissipation and recovery stress were evaluate. The NiTi bar with weight percentage of Ti-43.98 at. % Ni 56.02 and diameter of 8 mm. The tensile cyclic test obtained demonstrated a rounded loading curve based on a 0.2% offset. The as received bar exhibited superior pseudo-elastic behaviour and recentering through repeated cycling without significant degradation or permanent deformation but low energy dissipation due to narrow hysteresis while the steel rebar shows vice versa. Experimental results show potential for the use of SMAs in seismic applications and provide areas for continued research. It was conclude that the as-received pseudo elastic Ni-Ti bar is suitable use for seismic mitigation despite of their ability to undergo cyclical strains is 6% which is greater than 5%, with minimal residual strain, 0.15% which is less than 1%.