Evaluation of Seismic Response of Concrete Structures Reinforced by Shape Memory Alloys (Technical Note)

Shape memory alloys (SMAs) are a remarkable class of metals that can offer high strength, large energy dissipation through hysteretic behavior, extraordinary strain capacity (up to 8%) with full shape recovery to zero residual strain, and a high resistance to corrosion and fatigue—aspects that are all desirable from an earthquake engineering perspective. Their various physical characteristics result from solid-solid transformation between austenite and martensite phases of the alloy that may be induced by stress or temperature. The most commercially successful SMA is a binary alloy of nickel and titanium (NiTi). Although SMAs are expensive relative to most other materials used in seismic engineering, in certain forms their capacity for high energy loss per unit volume means that comparatively small quantities can be made to be especially effective, for example when used in wire form as part of a seismic bracing system. This state-of-the-art paper presents current materials science aspects, material models, and mechanical behavior of SMAs relevant to seismic engineering, and examines the current state of design of SMA-based seismic response modification devices and their use in buildings and bridges. SMA-based devices offer promising advantages for development of next-generation seismic protection systems.

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Shape memory alloys and offering superelastic property opportunity in reinforced concrete structures

Archives of Materials Science and Engineering ◽

10.5604/01.3001.0010.1553 ◽

2017 ◽

Vol 85 (1) ◽

pp. 5-13 ◽

Cited By ~ 1

Author(s):

M. Hosseini ◽

P. Beiranvand ◽

A. Dehestani ◽

K. Dehestani

Keyword(s):

Reinforced Concrete ◽

Shape Memory Alloy ◽

Shape Memory Alloys ◽

Elastic Property ◽

Shape Memory ◽

Concrete Structures ◽

Elastic Behaviour ◽

Concrete Column ◽

Reinforced Concrete Structures ◽

Reinforced Concrete Column

Purpose: The effect of shape memory and super-elastic property are two exclusive features in shape memory alloys. To exploit the properties of shape memory effect, alloy needs to be heated, but super-elastic property in these alloys will be proposed automatically in case suitable conditions. Design/methodology/approach: In this study, with simulating short-square reinforced concrete column experimental model in software ANSYS and in multi-level and increasing process, longitudinal armatures with shape memory alloy material will replace steel armatures with super-elastic behavior will be investigated with making shape memory alloy kind as variable (copper and nickel-based alloys), the opportunity of super-elastic property emergence in these alloys and with playing the role of longitudinal armature in reinforced concrete column. Findings: It can generally be said that memory alloy will achieve to goal that its created stresses will be located among stress of beginning direct phase and stress of finishing direct phase and whatever these stresses are closer to finishing direct phase, alloy will have more efficiency to propose its super-elastic property. Research limitations/implications: In case of using shape memory alloys as longitudinal armatures in reinforced concrete structures considering them buried in concrete, exploitation of shape memory property will have its particular problems that these problems won’t happen about the super-elastic property. Considering the high rate of strain capacity (3 to 8%) in memory alloys with super-elastic behaviour and the limitation of this capacity in concrete, conditions are necessary to be prepared in a way that memory alloy has the opportunity to propose super-elastic property. Originality/value: Except shape memory alloy that has proposing super-elastic behaviour in concrete structures and is investigated in this study, other factors such as the rate of resistance characteristic of pressure of concrete and mechanical characteristics of steel armatures are effective in this case as well that can be good subjects for investigation.

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