Modeling of a Shape Memory Alloy Beam and its Stochastic Chaos

2013 ◽  
Vol 479-480 ◽  
pp. 215-219
Author(s):  
Gen Ge ◽  
Jia Xu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Nonlinear Damping ◽  
Nonlinear Characteristic ◽  
Van Der Pol ◽  
Simply Supported ◽  
Stochastic Chaos ◽  
Strain Stress ◽  
Stress Relation ◽  
Hysteretic Cycle

The van-der-pol hysteretic cycle was applied to describe the hysteretic nonlinear characteristic of the strain-stress relation of a shape memory alloy (SMA). A new model with nonlinear damping of a simply supported SMA beam was proposed. The Criterions determining the stochastic chaos is obtained by the random Melnikov approach. The numerical results show the effectiveness of the theoretical analysis. Clear fractal boundaries of the system's safe basin is observed.

scholarly journals Response of a Shape Memory Alloy Beam Model under Narrow Band Noise Excitation

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Gen Ge
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Narrow Band ◽  
Multiple Scale ◽  
Nonlinear Damping ◽  
Beam Model ◽  
Narrow Band Noise ◽  
Band Noise ◽  
The Stability ◽  
The Moment

To describe the hysteretic nonlinear characteristic of the strain-stress relation of shape memory alloy (SMA), a Van-der-Pol hysteretic cycle is applied to simulate the hysteretic loops. Then, the model of a simply supported SMA beam subject to transverse narrow band noise excitation with nonlinear damping was proposed. The deterministic and the stochastic responses are studied, respectively, applying the multiple scale method. The stability of the steady state responses is analyzed by Floquet theory and the moment method. The numerical simulation results quite agree with the theoretical analysis.

Performance-based seismic loss assessment of isolated simply-supported highway bridges retrofitted with different shape memory alloy cable restrainers in a life-cycle context

2020 ◽  
Vol 31 (8) ◽  
pp. 1053-1075 ◽  
Author(s):  
Shuai Li ◽  
Farshad Hedayati Dezfuli ◽  
Jingquan Wang ◽  
M Shahria Alam
Keyword(s):  
Life Cycle ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Highway Bridges ◽  
Niti Shape Memory Alloy ◽  
Widespread Application ◽  
Simply Supported ◽  
Seismic Loss ◽  
Structural Applications

Shape memory alloy cables have emerged as an alternative to conventional steel cable restrainers for preventing the bridge spans from unseating during an extreme earthquake. Feasibility of high-cost NiTi shape memory alloy restrainers in retrofitting the bridges has been numerically investigated, and promising results have been published; however, considering the economic impacts, the effect of different types of shape memory alloy such as Cu-based and Fe-based shape memory alloy restrainers has not been discussed yet. The objective of this study is to address this problem in detail in order to propose the most cost-effective shape memory alloy restrainer suitable for bridge engineering applications. Seismic fragility and life-cycle loss (both direct and indirect) assessments are analytically performed on an isolated simply-supported highway bridge retrofitted by four types of shape memory alloy restrainers (i.e. NiTi, FeNiCoAlTaB, CuAlMn, and FeMnAlNi). Results showed that for all retrofitted bridges performed in the range of design displacement, the effect of type of shape memory alloy is significant on the damage probability and long-term seismic loss of the bridges. All the bridges retrofitted with shape memory alloy restrainers have a very low probability of collapse (less than 7%). It is also found that the bridge retrofitted with Fe-based shape memory alloy restrainers (SMA-II and SMA-IV) performed better as compared to the other cases. Compared to the bridge without restrainers and with NiTi shape memory alloy restrainers, Fe-based shape memory alloy restrainers can reduce the long-term loss by about 87% and 11%, respectively, at the design earthquake event specified in CHBDC-2014. The probabilistic risk analysis of highway bridges retrofitted with shape memory alloy restrainers can aid in paving the way toward widespread application of such smart materials in structural applications.

Structure and mobility of martensite variant interfaces in a Cu-Zn-AI shape memory alloy

2003 ◽  
Vol 112 ◽  
pp. 519-522 ◽  
Author(s):  
W. Cai ◽  
J. X. Zhang ◽  
Y. F. Zheng ◽  
L. C. Zhao
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Martensite Variant
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