Innovative Superelastic Isolation Device

Attanasi, Gabriele; Auricchio, Ferdinando

doi:10.1080/13632469.2011.562406

Cited by 39 publications

(29 citation statements)

References 22 publications

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“…The field of application of such a flexible device type is very large. The main interest at the base of this study was related to civil engineering application as a lateral restraining system (see Ref 2,3,9), because the superelastic spring is characterized by a large displacement capability and nonlinear-recentering force. Nevertheless all the applications for which superelastic recentering effect and a relatively large displacement capability is attractive can take advantage of this device configuration.…”

Section: Discussionmentioning

confidence: 99%

Theoretical and Experimental Investigation on SMA Superelastic Springs

Attanasi

Auricchio

Urbano

2011

J. of Materi Eng and Perform

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The mechanical behavior of superelastic springs is investigated in this study. The goal is to evaluate the device response and to exploit the material superelastic behavior, main concerns being material and geometrical response nonlinearity. The investigation is made of two parts, i.e., an experimental campaign and a numerical model proposal. Experimental tests have been performed on superelastic SMA coil springs considering load history in tension and compression for three different spring geometrical configurations. Tested specimens experience a maximum elongation larger than the original spring axis length. The response is not symmetric and under compression it is affected by buckling instability. Nevertheless, experimental results show a very good superelastic behavior with no damage and with negligible residual displacements. Numerical analyses have been performed to reproduce the experimental campaign results. A simple finite element model is proposed. Experimental and numerical result agreement is very good. The numerical model turns out to be a powerful design tool even for the very complex geometrical and material nonlinear conditions under investigation. Hence, it is proposed as a useful tool for spring design validation and response prediction.

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Section: Discussionmentioning

confidence: 99%

Theoretical and Experimental Investigation on SMA Superelastic Springs

Attanasi

Auricchio

Urbano

2011

J. of Materi Eng and Perform

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“…The behaviors of the SMA helical spring can be modeled using solid finite elements incorporating the stress-strain constitutive relationship of SMA material [12,13]. But it is generally impractical for nonlinear time history analysis of a complete engineering structure through such refined simulation method.…”

Section: Mechanical Model Of Sma Spring Restrainermentioning

confidence: 99%

“…For example, Speicher et al [11] developed a tension/compression damper making use of SMA helical springs, which provide stable recentering and damping characteristics. Attanasi and Auricchio [12] proposed conceptual design of an innovative restorable isolation system in which a sliding bearing is coupled with superelastic SMA helical springs that function for recentering purposes.…”

Section: Introductionmentioning

confidence: 99%

Performance of Seismic Restrainer with SMA Springs for Sliding Isolation of Single-Layer Spherical Lattice Shells

Peng

Wang

2016

Shock and Vibration

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The seismic response of a single-layer spherical lattice shell controlled by restorable sliding isolator is studied under different seismic excitations. The isolation system consists of flat steel-Teflon sliding isolators and superelastic SMA spring restrainers. The NiTi-SMA is used to fabricate helical spring for recentering control of the isolation system. In the first step of this investigation, the configuration scheme and functioning mechanism of a novel SMA spring restrainer are introduced briefly. Then, realistic mechanical behavior of large-scale superelastic NiTi helical spring is studied through a set of cyclic experimental tests. According to the obtained hysteresis loops, a mechanical model combining multilinear model and hysteresis model is developed to simulate the overall response of the SMA-based seismic restrainer. Besides, the sliding isolator is evaluated using a bilinear force-displacement hysteresis model. Finally, a 60 m span single-layer spherical lattice shell with substructure is modeled with finite element program. Nonlinear time history analyses of the controlled and uncontrolled lattice shell are performed considering multidimensional seismic inputs. The study shows that the seismic response of the controlled lattice shell can be effectively reduced by using isolation and control devices. Furthermore, the seismic response of the isolation system such as peak displacement and residual displacement can be effectively controlled by using the developed SMA spring restrainers.

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“…Wilde et al [9] developed a new base isolation device consisting of elastomeric bearings with two SMA bars working in tension and compression. Attanasi and Auricchio [10] proposed a base isolation device composed of a flat sliding bearing and eight SMA helical springs in a radial configuration. A theoretical damping ratio of approximately 9% was indicated.…”

Section: Introductionmentioning

confidence: 99%

“…The same problem was studied in more depth by Andrawes and DesRoches [2], who considered SMA restrainers and compared the efficiency of this solution with steel cables, metallic dampers and visco-elastic dampers. In general, SMA based solutions showed favourable performance with regard to the Structures 3 (2015) [1][2][3][4][5][6][7][8][9][10][11][12] mitigation of residual displacements, influenced by its re-centring properties.…”

Section: Introductionmentioning

confidence: 99%