Design and experimental analysis of a smart bearing using shape memory alloy springs

Among many rotating machinery vibration sources, there is one due to resonance, when the machine operation frequency crosses the natural frequency region. This study proposes a smart bearing that employs shape memory alloy NiTi helical springs for vibration-level reduction. This smart bearing is capable of dynamically changing its stiffness during machine acceleration or deceleration, keeping its natural frequency far from resonance. Activated by Joule effect and cooled by forced air convection, the prototype installed in horizontal rotating machinery reaches reduction of vibration amplitude of about 63% (root mean square) and 73% (Peak) at critical speed, with response time between 12–15 s. Compared with the results of the reference articles, satisfactory amplitude reduction and better response time were observed.

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An experimental investigation into the deployment of 3-D, finned wing and shape memory alloy vortex generators in a forced air convection heat pipe fin stack

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2011.03.015 ◽

2011 ◽

Vol 31 (14-15) ◽

pp. 2230-2240 ◽

Cited By ~ 24

Author(s):

M.S. Aris ◽

R. McGlen ◽

I. Owen ◽

C.J. Sutcliffe

Keyword(s):

Experimental Investigation ◽

Shape Memory Alloy ◽

Shape Memory ◽

Heat Pipe ◽

Vortex Generators ◽

Convection Heat ◽

Air Convection ◽

Forced Air

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Toward Low-Cost Highly Portable Tactile Displays with Shape Memory Alloys

Applied Bionics and Biomechanics ◽

10.1155/2007/543472 ◽

2007 ◽

Vol 4 (2) ◽

pp. 57-70 ◽

Cited By ~ 2

Author(s):

R. Velázquez ◽

E. E. Pissaloux ◽

M. Hafez ◽

J. Szewczyk

Keyword(s):

Shape Memory ◽

Active Element ◽

Low Cost ◽

Tactile Display ◽

Helical Springs ◽

Niti Sma ◽

Air Convection ◽

Tactile Displays ◽

Forced Air ◽

Visually Disabled

This paper presents a new concept of low-cost, high-resolution, lightweight, compact and highly portable tactile display. The prototype consists of an array of 8 × 8 upward/downward independent moveable pins based on shape memory alloy (SMA) technology. Each tactile actuator consists of an antagonist arranged pair of miniature NiTi SMA helical springs capable of developing a 300 mN pull force at 1.5 Hz bandwidth by using simple forced-air convection. The proposed concept allows the development of 200 g weight tactile instruments of compact dimensions which can be easily carried by a visually disabled user. A detailed technical description of the SMA active element, tactile actuator and tactile display is presented and discussed. Preliminary perceptual results confirm the effectiveness of the display on information transmission.

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Nickel–titanium shape memory alloy mechanical components produced by investment casting

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x18799197 ◽

2018 ◽

Vol 29 (19) ◽

pp. 3748-3757 ◽

Cited By ~ 6

Author(s):

Jackson de Brito Simões ◽

Carlos José de Araújo

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Investment Casting ◽

Mechanical Characterization ◽

Nickel Titanium ◽

Compression Tests ◽

Thermoelastic Martensitic Transformation ◽

Scanning Calorimetry ◽

Helical Springs ◽

Mechanical Components

This work aimed to produce mechanical components of nickel–titanium shape memory alloys using investment casting processes. Then, in order to validate processing, different designs of nickel–titanium shape memory alloy components as staple implants, Belleville springs, meshes, helical springs, screws and hexagonal honeycombs were produced and submitted to thermal and mechanical characterization. Thermoelastic martensitic transformation of the nickel–titanium shape memory alloy parts was determined by differential scanning calorimetry and electrical resistance with temperature, while the superelastic behaviour was verified by cyclic tensile and compression tests. It has been demonstrated that the employed investment casting processes are suitable to manufacture nickel–titanium shape memory alloy mechanical components with simple and complicated designs as well as functional properties related to phase transformation and superelasticity.

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Flexible Fingers Based on Shape Memory Alloy Actuated Modules

Machines ◽

10.3390/machines7020040 ◽

2019 ◽

Vol 7 (2) ◽

pp. 40 ◽

Cited By ~ 2

Author(s):

Daniela Maffiodo ◽

Terenziano Raparelli

Keyword(s):

Mathematical Model ◽

Shape Memory Alloy ◽

Shape Memory ◽

Basic Concept ◽

Experimental Tests ◽

Simple Mathematical Model ◽

Joule Effect ◽

Antagonistic Action ◽

Preliminary Results

To meet the needs of present-day robotics, a family of gripping flexible fingers has been designed. Each of them consists of a number of independent and flexible modules that can be assembled in different configurations. Each module consists of a body with a flexible central rod and three longitudinally positioned shape memory alloy (SMA) wires. When heated by the Joule effect, one to two SMA wires shorten, allowing the module to bend. The return to undeformed conditions is achieved in calm air and is guaranteed by the elastic bias force exerted by the central rod. This article presents the basic concept of the module and a simple mathematical model for the design of the device. Experimental tests were carried out on three prototypes with bodies made of different materials. The results of these tests confirm the need to reduce the antagonistic action of the inactive SMA wires and led to the realization of a fourth prototype equipped with an additional SMA wire-driven locking/unlocking device for these wires. The preliminary results of this last prototype are encouraging.

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A combined analytical, numerical, and experimental study of shape-memory-alloy helical springs

International Journal of Solids and Structures ◽

10.1016/j.ijsolstr.2010.10.026 ◽

2011 ◽

Vol 48 (3-4) ◽

pp. 611-624 ◽

Cited By ~ 57

Author(s):

Reza Mirzaeifar ◽

Reginald DesRoches ◽

Arash Yavari

Keyword(s):

Experimental Study ◽

Shape Memory Alloy ◽

Shape Memory ◽

Helical Springs

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Shape Memory Alloy Based Rotational Actuator

Volume 4B: Dynamics, Vibration, and Control ◽

10.1115/imece2018-87646 ◽

2018 ◽

Author(s):

Nick Hofmann ◽

Michael P. Hennessey

Keyword(s):

Shape Memory ◽

Rotational Motion ◽

Thermal Analyses ◽

Peak Torque ◽

Advanced Materials ◽

Constant Torque ◽

Heating And Cooling ◽

Air Convection ◽

Technological Developments ◽

Forced Air

Due to recent technological developments in advanced materials, the integration of shape memory alloys (SMAs) into new machines and mechanisms is becoming more common and it offers tremendous potential for the future. Using currently available properties of common SMA materials, the paper’s contribution is to: Study through dynamic simulation the potential offered by SMA springs to serve as the basis for rotary actuation. In the process, the SMA displaces a rocker arm rotating about an axis to induce rotational motion of a driveshaft, in effect converting a force into rotational motion. When embedded in a cycle with heating & cooling phases and a resetting mechanism, unidirectional rotational motion can be achieved. Regarding heating and cooling cycles, forced air convection is used to reduce thermal cycle cooling and is calculated via transient thermal analyses. Using typical parameter values for the representative design considered, through forced air convection, cooling cycles are reduced from approximately 30 seconds (natural) to 5.5 seconds (forced) and as a result, a complete system cycle can occur in 10 seconds, with the applied inertial load of 2.0 kg-m2. Using MATLAB and Simulink, a nonlinear 3rd order dynamic system model was created and simulations were performed. One complicating factor concerned angular limits and the necessary thermal cycling, which was solved through appropriate sequencing and resetting of integrators for different phases. Simulation results for the design considered show that a peak torque of 1.72 N-m is possible and that relatively smooth motion and approximately constant torque output is also possible through the addition of a few more rocker arm systems, properly commutated. Lastly, the design analysis framework and results may inspire future realization of actual devices.

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Analysis of Time Response of Shape Memory Alloy Actuators Modular System

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.147-149.726 ◽

2009 ◽

Vol 147-149 ◽

pp. 726-731

Author(s):

Dan Mândru ◽

Ion Lungu ◽

Simona Noveanu ◽

Mihai Olimpiu Tătar

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Heating Time ◽

Time Response ◽

Modular System ◽

Resistive Heating ◽

Helical Springs ◽

Active Elements ◽

Compact Design

The first part of the paper treats the general problems concerning the shape memory alloy actuators and their operation principle. Then, our work referring to the developing a modular family of linear and rotational actuators, realized in many typo dimensions, in a compact design, with facile connection with the actuated mechanisms and supplying module is presented. The active elements of these actuators are shape memory alloy wires, ribbons and helical springs. The influence of the geometry of the active elements on the time response is studied. The most important solutions to reduce the resistive heating time of active elements and to improve the time response on cooling are identified.

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