Nonlinear dynamics of a rotordynamic nonsmooth shape memory alloy system

2013 ◽  
Vol 332 (3) ◽  
pp. 608-621 ◽  
Author(s):  
Leandro C. Silva ◽  
Marcelo A. Savi ◽  
Alberto Paiva
Keyword(s):  
Nonlinear Dynamics ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Alloy System

Computational thermodynamics of the CoNiGa high temperature shape memory alloy system

Calphad ◽  
2014 ◽  
Vol 45 ◽  
pp. 167-177 ◽  
Author(s):  
Arpita Chari ◽  
Ebubekir Dogan ◽  
Anjana Talapatra ◽  
Avinash. R. Chivukula ◽  
Andres Garay ◽  
...  
Keyword(s):  
High Temperature ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Alloy System ◽  
Computational Thermodynamics

Thermal Properties, Microstructure and Microhardness of Cu–Al–Co Shape Memory Alloy System

2014 ◽  
Vol 67 (4) ◽  
pp. 595-600 ◽  
Author(s):  
Yıldırım Aydoğdu ◽  
Ferdi Kürüm ◽  
Mediha Kök ◽  
Zehra Deniz Yakinci ◽  
Ayşe Aydoğdu
Keyword(s):  
Thermal Properties ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Alloy System

Nonlinear dynamics and chaos in a shape memory alloy pseudoelastic oscillator

2007 ◽  
Author(s):  
Luciano G. Machado ◽  
Dimitris C. Lagoudas ◽  
Marcelo A. Savi
Keyword(s):  
Nonlinear Dynamics ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Nonlinear Dynamics And Chaos

Design of a Multiple-Actuation Shape Memory Alloy Pipe Coupler: Material Development and Characterization

2012 ◽  
Author(s):  
Majid Tabesh ◽  
John Rohmer ◽  
James G. Boyd ◽  
Dimitris C. Lagoudas ◽  
Kadri C. Atli ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Contact Pressure ◽  
Niti Alloy ◽  
Internal Surface ◽  
Alloy System ◽  
Longitudinal Direction ◽  
The State ◽  
Pipe System ◽  
Material Development

Shape memory alloy (SMA) pipe couplers use the shape memory effect to apply a contact pressure onto the surface of the pipes to be coupled. In the current research, an SMA pipe coupler is designed, fabricated and tested. The thermally induced contact pressure depends on several factors such as the dimensions and properties of the coupler-pipe system. An in-house developed NiTi alloy system is considered for the coupler. The coupling pressure is measured using strain gages mounted on the internal surface of an elastic steel ring. Thermal actuation response of the coupler is determined under both stressed and stress-free conditions. In addition, the state of anisotropy is investigated in the coupler by characterizing samples in the longitudinal and transverse directions. Unlike the commercially available NiTiNb couplers, the NiTi coupler demonstrates a multiple actuation response and higher contact pressure. The state of anisotropy is investigated in the couplers by characterizing samples in the longitudinal and transverse directions. The results show no change in transformation temperatures with respect to two perpendicular transverse and longitudinal directions, however, the material can undergo higher transformation strains in the longitudinal direction.

Phase Equilibria and Phase Transition of the Ni–Fe–Ga Ferromagnetic Shape Memory Alloy System

2007 ◽  
Vol 38 (4) ◽  
pp. 767-776 ◽  
Author(s):  
Katsunari Oikawa ◽  
Toshihiro Omori ◽  
Yuji Sutou ◽  
Haruhiko Morito ◽  
Ryosuke Kainuma ◽  
...  
Keyword(s):  
Phase Transition ◽  
Shape Memory Alloy ◽  
Phase Equilibria ◽  
Shape Memory ◽  
Alloy System ◽  
Ferromagnetic Shape Memory Alloy ◽  
Ferromagnetic Shape Memory

Mitigation of Vertical and Horizontal Seismic Excitations on Bridges Utilizing Shape Memory Alloy System

2013 ◽  
Vol 831 ◽  
pp. 90-94 ◽  
Author(s):  
H. Aryan ◽  
M. Ghassemieh
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Three Dimensional ◽  
Time History ◽  
Alloy System ◽  
Practical Method ◽  
Nonlinear Time History Analysis ◽  
Vertical Acceleration ◽  
Three Dimensional Model ◽  
Seismic Excitations

Vertical seismic excitation has a tremendous effect on bridges and many researchers have pointed out bridges damages occurred during the past significant earthquakes which were direct results of ignoring vertical acceleration of ground motions. Many studies have emphasized the importance of extending practical methods to reduce effects of vertical acceleration of earthquakes besides effects of horizontal accelerations; but no practical method has proposed up to now. In this article, an innovative shape memory alloy system is proposed for bridges that can simultaneously controls effects of vertical and horizontal seismic excitations on bridge and reduce them. To evaluate the effectiveness of the shape memory alloy system, a nonlinear time history analysis is conducted on a detailed three-dimensional model of a multi-span simply supported bridge using a representative ground motion. The results show that the proposed new system is very effective for reducing effects of vertical and horizontal seismic excitations on bridges.

Promising ferromagnetic Ni–Co–Al shape memory alloy system

2001 ◽  
Vol 79 (20) ◽  
pp. 3290-3292 ◽  
Author(s):  
K. Oikawa ◽  
L. Wulff ◽  
T. Iijima ◽  
F. Gejima ◽  
T. Ohmori ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Alloy System

scholarly journals Multistrand, Fast Reaction, Shape Memory Alloy System for Uninhabited Aerial Vehicle Flight Control

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
M. Brennison ◽  
R. M. Barrett ◽  
L. Kerth
Keyword(s):  
Control System ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Flight Control ◽  
Alloy System ◽  
Open Loop ◽  
Flight Control System ◽  
Loop Design ◽  
Aerial Vehicle ◽  
Sma Actuator

This paper details an investigation of shape memory alloy (SMA) filaments which are used to drive a flight control system with precision control in a real flight environment. An antagonistic SMA actuator was developed with an integrated demodulator circuit from a JR NES 911 subscale UAV actuator. Most SMA actuator studies concentrate on modeling the open-loop characteristics of such a system with full actuator performance modeling. This paper is a bit different in that it is very practically oriented and centered on development of a flight-capable system which solves the most tricky, practical problems associated with using SMA filaments for aircraft flight control. By using well-tuned feedback loops, it is shown that intermediate SMA performance prediction is not appropriate for flight control system (FCS) design. Rather, capturing the peak behavior is far more important, along with appropriate feedback loop design. To prove the system, an SMA actuator was designed and installed in the fuselage of a 2 m uninhabited aerial vehicle (UAV) and used to control the rudder through slips and coordinated turns. The actuator was capable of 20 degrees of positive and negative deflection and was capable of 7.5 in-oz (5.29 N cm) of torque at a bandwidth of 2.8 Hz.

Influence of hysteresis loop shape on the nonlinear dynamics of shape memory alloy oscillator excited by non-ideal energy sources

2014 ◽  
Author(s):  
V. Piccirillo ◽  
A. M. Tusset ◽  
J. M. Balthazar ◽  
D. Bernardini ◽  
G. Rega
Keyword(s):  
Nonlinear Dynamics ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Hysteresis Loop ◽  
Energy Sources ◽  
Loop Shape
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