Experimental and theoretical evaluation of the behavior of a shape memory alloy Belleville washer under different operating conditions

2002 ◽  
Author(s):  
C. Labrecque ◽  
M. Braunovic ◽  
P. Terriault ◽  
F. Trochu ◽  
M. Schetky
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Operating Conditions ◽  
Theoretical Evaluation

Force transmissibility characteristics of a pseudoelastic oscillator

2019 ◽  
Vol 31 (3) ◽  
pp. 349-363 ◽  
Author(s):  
Sebin Jose ◽  
Goutam Chakraborty ◽  
Ranjan Bhattacharyya
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Cooling Rate ◽  
Operating Conditions ◽  
Vibration Isolator ◽  
Resonant Frequencies ◽  
Single Degree Of Freedom ◽  
Thermomechanical Behaviour ◽  
Rigid Mass ◽  
Force Transmissibility

The force transmissibility characteristics of a passive vibration isolator in the form of shape memory alloy bar are investigated. The shape memory alloy bar, together with a rigid mass, constitutes a single-degree-of-freedom system. The force isolation ability of the oscillator is evaluated for both isothermal and convective environmental conditions. The transmissibility curve of an isothermal pseudoelastic oscillator displays single and double jumps depending upon the forcing amplitude. The shape memory alloy oscillator with coupled thermomechanical behaviour depends on the cooling rate near resonant frequencies. Increased cooling rate reduces both peak amplitude and the resonant frequency of the transmissibility curve. The force isolation provided by shape memory alloy oscillator is independent of the operating conditions.

A Shape Memory Alloy-Based Morphing Axial Fan Blade: Part II — Blade Shape and CFD Analyses

2015 ◽  
Author(s):  
Alessio Suman ◽  
Annalisa Fortini ◽  
Nicola Aldi ◽  
Mattia Merlin ◽  
Michele Pinelli
Keyword(s):  
Wind Tunnel ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Fluid Dynamic ◽  
Rotational Velocity ◽  
Strong Relationship ◽  
Operating Conditions ◽  
Automotive Application ◽  
Axial Fan ◽  
Fan Performance

The ability of a morphing blade to change its geometry according to the different operating conditions represents a challenging approach for the optimization of turbomachinery performance. In this paper experimental and CFD numerical analyses on a morphing blade for a heavy-duty automotive cooling axial fan are proposed. Starting from the experimental results proposed in the first part of this work, a morphing blade, made of Shape Memory Alloy (SMA) strips embedded in a polymeric structure, was thoroughly tested. In order to assess the ability of the strips to reach a progressive and smooth shape changing evolution, several experiments were performed in a purpose-built wind tunnel. The morphing blade changed its shape as the strips were thermally activated by means of air stream flow. The bending deformation evolution with the increasing number of thermal cycles was evaluated by digital image analysis techniques. After the analyses in the wind tunnel CFD numerical simulations of a partially shrouded fan composed of five morphing blades were performed in order to highlight the evolution of the fan performance according to air temperature conditions. In particular, the capability of the blade activation was evaluated by the comparison between the fan performance with non-activated blades and with activated blades. The results show a progressive stabilization of the shape memory behavior after the first cycle. The blade deformation led to a significant improvement in fan performance at a constant rotational velocity. The CFD numerical simulation points out the differences in the overall performance and of three-dimensional fluid dynamic behavior of the fan. This innovative concept is aimed at realizing a sensorless smart fan control, permitting (i) an energy saving that leads to fuel saving in the automotive application fields and (ii) an increase in engine life thanks to a strong relationship between the engine thermal request and the cooling fan performance.

A Shape Memory Alloy-Based Morphing Axial Fan Blade—Part II: Blade Shape and Computational Fluid Dynamics Analyses

2015 ◽  
Vol 138 (6) ◽  
Author(s):  
Alessio Suman ◽  
Annalisa Fortini ◽  
Nicola Aldi ◽  
Mattia Merlin ◽  
Michele Pinelli
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Tunnel ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Fluid Dynamic ◽  
Operating Conditions ◽  
Automotive Application ◽  
Axial Fan ◽  
Fan Performance

The ability of a morphing blade to change its geometry according to the different operating conditions represents a challenging approach for the optimization of turbomachinery performance. In this paper, experimental and computational fluid dynamics (CFD) numerical analyses on a morphing blade for a heavy-duty automotive cooling axial fan are proposed. Starting from the experimental results proposed in the first part of this work, a morphing blade, made of shape memory alloy (SMA) strips embedded in a polymeric structure, was thoroughly tested. In order to assess the ability of the strips to reach a progressive and smooth shape changing evolution, several experiments were performed in a purpose-built wind tunnel. The morphing blade changed its shape as the strips were thermally activated by means of air stream flow. The bending deformation evolution with the increasing number of thermal cycles was evaluated by digital image analysis techniques. After the analyses in the wind tunnel, CFD numerical simulations of a partially shrouded fan composed of five morphing blades were performed in order to highlight the evolution of the fan performance according to air temperature conditions. In particular, the capability of the blade activation was evaluated by the comparison between the fan performance with nonactivated blades and with activated blades. The results show a progressive stabilization of the shape memory behavior after the first cycle. The blade deformation led to a significant improvement in the fan performance at a constant rotational velocity. The CFD numerical simulation points out the differences in the overall performance and of three-dimensional fluid dynamic behavior of the fan. This innovative concept is aimed at realizing a sensorless smart fan control, permitting (i) an energy saving that leads to fuel saving in the automotive application fields and (ii) an increase in engine life, thanks to a strong relationship between the engine thermal request and the cooling fan performance.

Failures of Mechanical Springs

2021 ◽  
pp. 402-414
Author(s):  
Dana J. Medlin
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Fatigue Failure ◽  
Failure Mechanisms ◽  
Operating Conditions ◽  
Material Defects ◽  
Common Causes ◽  
Mechanical Components ◽  
Fatigue Failures

Abstract Mechanical springs are used in mechanical components to exert force, provide flexibility, and absorb or store energy. This article provides an overview of the operating conditions of mechanical springs. Common failure mechanisms and processes involved in the examination of spring failures are also discussed. In addition, the article discusses common causes of failures and presents examples of specific spring failures, describes fatigue failures that resulted from these types of material defects, and demonstrates how improper fabrication can result in premature fatigue failure. It also covers failures of shape memory alloy springs and failures caused by corrosion and operating conditions.

scholarly journals Design and performance analysis of hydraulic switching valve driven by magnetic shape memory alloy

2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110169
Author(s):  
Hu Shi ◽  
Zhaoying Liu ◽  
Haitao Wang ◽  
Xuesong Mei
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Simulation Analysis ◽  
Dynamic Performance ◽  
Fast Response ◽  
Operating Conditions ◽  
Step Response ◽  
Magnetic Shape Memory ◽  
Switching Valve ◽  
Magnetic Shape Memory Alloy

In this paper, the hydraulic switching valve is designed and its dynamic performance is investigated through proposing a fast response actuator with magnetic shape memory alloy (MSMA) to drive the valve. MSMA actuator with spring return is designed and a double-layered coil is constructed to achieve compactness of electromagnetic case. The dynamic characteristics of the MSMA actuator are analyzed and the step response characteristics is tested. Hydraulic switching valve with MSMA actuator is designed with poppet type. Pressure and velocity field in the flow channel under different valve opening and different inlet and outlet pressure differences are analyzed in COMSOL Multiphysics software. The dynamics of the valve poppet during opening and closing process is modeled mathematically, and simulation analysis are conducted in AMESim software to analyze the response of valve under step and square wave signals. The step response of output flow rate and pressure-flow characteristic under different operating conditions are obtained through experiment. The results show that the MSMA based valve can achieve fast response with opening time of 5 ms at the pressure difference of 1 MPa, providing a theoretical support for the development of hydraulic switching valve with high performance actuator driven by MSMA.

Analysis of long wind turbine blades with shape memory alloy wires in super-elastic phase

2018 ◽  
Vol 29 (15) ◽  
pp. 3108-3123 ◽  
Author(s):  
Rodrigo Nicoletti ◽  
Robert Liebich
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Wind Profile ◽  
Turbine Blades ◽  
Wind Turbine Blade ◽  
Operating Conditions ◽  
Hysteretic Behavior ◽  
Alloy Material

In this work, shape memory alloy wires are modeled and included in the model of a wind turbine blade, in order to numerically study their effect on blade vibrations under operating conditions. The blade is modeled using finite elements considering flapwise, edgewise, and torsional motion subjected to the effects of rotation and to a normal wind profile. The shape memory alloy wires are modeled in the super-elastic phase, thus presenting a hysteresis loop as a function of strain and ambient temperature. Such a hysteretic behavior of the shape memory alloy material adds damping to the structure that it is attached to. The numerical results show that inserting shape memory alloy wires in the wind turbine blade presents drawbacks, because the excitation level of the normal wind profile is not big enough for the blade to present significant strain. Hence, the hysteresis loops in the shape memory alloy material mounted on the blade have small areas which, consequently, reduce the amount of damping added to the blade. Besides, the added damping is restricted to the upper 30% of the blade (area of higher strain in the blade).

PROGRESS ON THE DEVELOPMENT OF SHAPE-MEMORY-ALLOY METACOMPOSITES

2021 ◽  
Author(s):  
DUSAN MILOSAVLJEVIC ◽  
QIANLONG ZHANG ◽  
MARCO MOSENEDER ◽  
HONGFEI ZHU ◽  
NORA LECIS ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Composite Structures ◽  
Dynamic Properties ◽  
Research Effort ◽  
Mechanical Energy ◽  
Engineering Application ◽  
Operating Conditions ◽  
Development Effort

Shape memory alloys (SMA) have long been explored as a semi-passive approach to mechanical energy dissipation particularly, but not exclusively, for application to vibration control. More recently, the integration of SMAs in composite materials has opened the opportunity to synthesize tunable composite structures exhibiting significantly enhanced energy dissipation characteristics and a certain degree of adaptability to different operating conditions. Despite the significant progress in the development and manufacturing of SMAs over the past several decades, the cost of common Ni-based alloys has remained an important factor hindering their widespread engineering application. The long-term goal of this research effort is to model, design, and fabricate shape-memory-alloy (SMA) meta-composites employing lower volume fractions of a more affordable Cu-based alloy, while still enabling enhanced and tunable dynamic properties. This paper summarizes recent progress in the development of the meta-composite platform and focuses on aspects involving both numerical modeling and fabrication of SMA materials. On the modeling side, particular emphasis is given to assess the ability to tune the dynamic performance of continuous SMA structures by exploiting the different phases and transformations of the alloy. On the other side, the material development effort focuses on the identification of the optimal chemical composition, mechanical and heat treatment processes. A combination of numerical and experimental results is presented to illustrate capabilities and opportunities presented by this material platform.

scholarly journals Influence of Structural Parameters of Shape Memory Alloy Corrugated Gaskets on the Contact Pressure of Bolted Flange Joints

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Liang He ◽  
Xiaofeng Lu ◽  
Xiaolei Zhu ◽  
Qing Chen
Keyword(s):  
Finite Element ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Contact Pressure ◽  
Structural Parameters ◽  
Maximum Error ◽  
Operating Conditions ◽  
Element Analysis ◽  
Mechanical Coupling ◽  
Bolted Flange

Shape memory alloy corrugated gaskets (SMA-CGs) can adapt to fluctuating working conditions due to their pseudoelasticity (PE) and shape memory effect (SME), which make them excellent sealing components. In this study, the deformation mechanism of SMA-CGs was examined according to their structural properties under installation and operating conditions to establish an SMA-CG thermal-mechanical coupling model with the finite element analysis (FEA) method, which has been verified through experimentation. Based on this, a thermal-mechanical coupling FEA model was built for a bolted flange joint with SMA-CG. The influence of the SMA-CG structure parameters on compression-rebound mechanical properties was also studied under installation and operating conditions. The conclusions are as follows: a thermal-mechanical coupling finite element analysis method was established for NiTi alloy corrugated structures. Through comparison with the experimental results, the maximum error of the maximum compression load was 5.78%, the maximum error of the rebound rate was 8.85%, and the maximum error of the maximum compaction force in the heat recovery stage was 12.2%, all of which were within the <15% acceptable error range of engineering fields. According to the related experiments and finite element results, the maximum compressive force of gasket thermal recovery after unloading was not less than 40% of the initial maximum compressive load. The application of shape memory alloy to corrugated gasket significantly improved its ability in coping with fluctuating load temperatures. The contact pressure of corrugation increased with the increase of sheet thickness (T) and corrugated gasket height (H) under installation and operating conditions, showing a decreasing trend with the increase of pitch (P), of which the order of factors influencing the average contact pressure of corrugated gasket was sheet T > H > P, and when structural parameters of SMA-CG were T = 0.6 mm, H = 4 mm, and P = 2.5 mm, the contact pressure of corrugated gasket was the highest under operating conditions.

Use of shape memory alloy for active shock control bump application

2021 ◽  
pp. 1045389X2110386
Author(s):  
Jinhao Qiu ◽  
Lin Hao ◽  
Hongli Ji ◽  
Chen Zhang ◽  
Rui Nie
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Mechanical Response ◽  
Shape Change ◽  
Operating Conditions ◽  
Training Procedure ◽  
Scanning Calorimetry ◽  
Mechanical Responses ◽  
Shock Control Bump ◽  
Shock Control

A shape memory alloy (SMA) with composition of Ni50.1Ti49.9 (at. %) was used for fabrication of a 3-D bump structure intended for use as an active shock control bump (SCB) into a transonic wing. This kind of bump is a variable-geometry structure designed to reduce the drag induced by shock wave ensure wing’s aerodynamic performance over the entire range of operating conditions. To meet this target, the SMA bump requires to exhibit two-way shape memory effect (TWSME) so that it can yield continuous shape change by properly changing the driving temperature. Result from differential scanning calorimetry was first presented to provide material’s phase transformation temperatures. To obtain the TWSME, a thermo-mechanical training procedure was proposed and a set of training devices were designed for training SMA bump. The SMA bump in this paper is trained to have a relatively flat shape in high temperature and can swell up when cooling. After more than 80 times training, the TWSME of the material tends to be stable. Then the thermo-mechanical responses of the SMA bump which is subjected to about 100 times training was tested. The result shows that the trained SMA bump can generate about 1.2 mm maximum recoverable deformation during martensitic transformation, which is about 3% of the ratio of the deformation region. Finally, the influence of external load on the thermo-mechanical response of the trained SMA bump were also studied.

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