scholarly journals A Novel Self-Deployable Solar Sail System Activated by Shape Memory Alloys

Aerospace ◽  
2019 ◽  
Vol 6 (7) ◽  
pp. 78 ◽  
Author(s):  
Gianluigi Bovesecchi ◽  
Sandra Corasaniti ◽  
Girolamo Costanza ◽  
Maria Elisa Tata
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Environmental Conditions ◽  
Solar Sail ◽  
Operating Conditions ◽  
Small Scale ◽  
Space Vehicles ◽  
Solar Sails ◽  
Suitable Material ◽  
Transfer Mechanisms

This work deals with the feasibility and reliability about the use of shape memory alloys (SMAs) as mechanical actuators for solar sail self-deployment instead of heavy and bulky mechanical booms. Solar sails exploit radiation pressure a as propulsion system for the exploration of the solar system. Sunlight is used to propel space vehicles by reflecting solar photons from a large and light-weight material, so that no propellant is required for primary propulsion. In this work, different small-scale solar sail prototypes (SSP) were studied, manufactured, and tested for bending and in three different environmental conditions to simulate as much as possible the real operating conditions where the solar sails work. Kapton is the most suitable material for sail production and, in the space missions till now, activated booms as deployment systems have always been used. In the present work for the activation of the SMA elements some visible lamps have been employed to simulate the solar radiation and time-temperature diagrams have been acquired for different sail geometries and environmental conditions. Heat transfer mechanisms have been discussed and the minimum distance from the sun allowing the full self-deployment of the sail have also been calculated.

A novel methodology for solar sail opening employing shape memory alloy elements

2018 ◽  
Vol 29 (9) ◽  
pp. 1793-1798 ◽  
Author(s):  
Girolamo Costanza ◽  
Maria Elisa Tata
Keyword(s):  
Shape Memory ◽  
Atmospheric Condition ◽  
Low Pressure ◽  
Small Scale ◽  
Space Vehicles ◽  
Halogen Lamp ◽  
Solar Sails ◽  
Suitable Material ◽  
Activation Times ◽  
Al Coating

Solar sails exploit the radiation pressure as propulsion system. Sunlight is used to propel space vehicles by reflecting solar photons from a large and lightweight material, so that no propellant is required for primary propulsion. Kapton seems to be the most suitable material for the sail production and in the space missions till now activated booms as deployment systems have always been used. In this work, an innovative self-deploying system based on NiTi shape memory wires has been designed and manufactured in a small-scale prototype. As kapton has always been employed with a thin Al coating on the surface of the sail, commercial pure Al thin sheets with thin adhesive kapton have been used in order to simulate the sail. The attention has been focused, in the deployment experiments performed in the laboratory, on the effect of different heating methods and different pressure conditions on the activation times. The folded configuration chosen has been deployed in atmospheric condition and in low pressure condition (0.05 bar) inside a oven connected to a rotary pump. For what concerns the heating methods, the attention has been focused on low-pressure oven ISCO NSV 9035 (1.3 kW) and on halogen lamp (1 kW) in order to obtain the self-deployment of the sail. Some comparisons between the two configurations in the different environmental conditions have been performed. In all cases, the full self-activation of the sail has been achieved.

scholarly journals Shape Memory Activated Self-Deployable Solar Sails: Small-Scale Prototypes Manufacturing and Planarity Analysis by 3D Laser Scanner

Actuators ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 38 ◽  
Author(s):  
Alberto Boschetto ◽  
Luana Bottini ◽  
Girolamo Costanza ◽  
Maria Elisa Tata
Keyword(s):  
Shape Memory ◽  
Laser Scanner ◽  
Solar Sail ◽  
Small Scale ◽  
Propulsive Force ◽  
Momentum Exchange ◽  
Solar Sails ◽  
Level Curves ◽  
Wolfram Mathematica ◽  
Critical Zones

Solar sails are propellantless systems where the propulsive force is given by the momentum exchange of reflecting photons. Thanks to the use of shape memory alloys for the self-actuation of the system, complexity of the structure itself has decreased and so has the weight of the whole structure. Four self-deploying systems based on the NiTi shape memory wires have been designed and manufactured in different configurations (wires disposal and folding number). The deployed solar sails surfaces have been acquired by a Nextengine 3D Laser Scanner based on the Multistripe Triangulation. 3D maps have been pre-processed through Geomagic Studio and then elaborated in the Wolfram Mathematica environment. The planarity degree has been evaluated as level curves from the regression plane highlighting marked differences between the four configurations and locating the vertices as the most critical zones. These results are useful in the optimization of the best folding solution both in the weight/surface reduction and in the planarity degree of the solar sail.

scholarly journals Design and Characterization of a Small-Scale Solar Sail Prototype by Integrating NiTi SMA and Carbon Fibre Composite

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Girolamo Costanza ◽  
Gabriele Leoncini ◽  
Fabrizio Quadrini ◽  
Maria Elisa Tata
Keyword(s):  
Carbon Fibre ◽  
Shape Memory ◽  
Fibre Composite ◽  
Weight Ratio ◽  
Solar Sail ◽  
Structure Design ◽  
Small Scale ◽  
Momentum Exchange ◽  
Carbon Fibre Composite ◽  
Solar Sails

Solar sails are propellantless systems where the propulsive force is given by the momentum exchange of reflecting photons. In this study, a self-deploying system based on NiTi shape memory wires and sheets has been designed and manufactured. A small-scale prototype of solar sail with carbon fibre loom has been developed. Different configurations have been tested to optimize material and structure design of the small-scale solar sail. In particular the attention has been focused on the surface/weight ratio and the deployment of the solar sail. By reducing weight and enlarging the surface, it is possible to obtain high values of characteristic acceleration that is one of the main parameters for a successful use of the solar sail as propulsion system. Thanks to the use of shape memory alloys for self-actuation of the system, complexity of the structure itself decreases. Moreover, sail deployment is simpler.

Micro pulling down growth of very thin shape memory alloys single crystals

2017 ◽  
Vol 10 (01) ◽  
pp. 1740003 ◽  
Author(s):  
I. López-Ferreño ◽  
J. San Juan ◽  
T. Breczewski ◽  
G. A. López ◽  
M. L. Nó
Keyword(s):  
Mechanical Properties ◽  
Shape Memory Alloys ◽  
Single Crystal ◽  
Shape Memory ◽  
Single Crystals ◽  
Functional Materials ◽  
Small Scale ◽  
Cylindrical Shape ◽  
Minimum Diameter ◽  
Wide Range

Shape memory alloys (SMAs) have attracted much attention in the last decades due to their thermo-mechanical properties such as superelasticity and shape memory effect. Among the different families of SMAs, Cu–Al–Ni alloys exhibit these properties in a wide range of temperatures including the temperature range of 100–200[Formula: see text]C, where there is a technological demand of these functional materials, and exhibit excellent behavior at small scale making them more competitive for applications in Micro Electro-Mechanical Systems (MEMS). However, polycrystalline alloys of Cu-based SMAs are very brittle so that they show their best thermo-mechanical properties in single-crystal state. Nowadays, conventional Bridgman and Czochralski methods are being applied to elaborate single-crystal rods up to a minimum diameter of 1[Formula: see text]mm, but no works have been reported for smaller diameters. With the aim of synthesizing very thin single-crystals, the Micro-Pulling Down ([Formula: see text]-PD) technique has been applied, for which the capillarity and surface tension between crucible and the melt play a critical role. The [Formula: see text]-PD method has been successfully applied to elaborate several cylindrical shape thin single-crystals down to 200[Formula: see text][Formula: see text]m in diameter. Finally, the martensitic transformation, which is responsible for the shape memory properties of these alloys, has been characterized for different single-crystals. The experimental results evidence the good quality of the grown single-crystals.

scholarly journals Deployment of Solar Sails by Joule Effect: Thermal Analysis and Experimental Results

Aerospace ◽  
2020 ◽  
Vol 7 (12) ◽  
pp. 180
Author(s):  
Gianluigi Bovesecchi ◽  
Sandra Corasaniti ◽  
Girolamo Costanza ◽  
Fabrizio Paolo Piferi ◽  
Maria Elisa Tata
Keyword(s):  
Thermal Analysis ◽  
Solar Sail ◽  
Electrical Circuit ◽  
Nickel Titanium ◽  
Design Parameters ◽  
Space Vehicles ◽  
The Sun ◽  
Solar Sails ◽  
Joule Effect ◽  
Electrical Circuits

Space vehicles may be propelled by solar sails exploiting the radiation pressure coming from the sun and applied on their surfaces. This work deals with the adoption of Nickel-Titanium Shape Memory Alloy (SMA) elements in the sail deployment mechanism activated by the Joule Effect, i.e., using the same SMA elements as a resistance within suitable designed electrical circuits. Mathematical models were analyzed for the thermal analysis by implementing algorithms for the evaluation of the temperature trend depending on the design parameters. Several solar sail prototypes were built up and tested with different number, size, and arrangement of the SMA elements, as well as the type of the selected electrical circuit. The main parameters were discussed in the tested configurations and advantages discussed as well.

Development and Testing of a Hybrid SMA/MR Passive Clutch

2014 ◽  
Author(s):  
Francesco Bucchi ◽  
Mohammad Elahinia ◽  
Paola Forte ◽  
Francesco Frendo
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Smart Materials ◽  
Permanent Magnets ◽  
Power Saving ◽  
Vacuum Pump ◽  
Operating Conditions ◽  
Key Factor ◽  
Low Torque ◽  
Water Pumps

The reduction of consumption and emissions is a key factor in modern vehicle design. The overall vehicle efficiency is pursued in several ways, including the reduction of consumption of the auxiliary devices (e.g. water pumps, oil pumps, vacuum pumps etc.). In this paper, using two different smart materials (i.e. magnetorheological fluids and shape memory alloys) a device aimed at disengaging the vacuum pump was developed. The conceived device is composed of a magnetorheological (MR) clutch excited by permanent magnets coaxially manufactured with a sliding spline sleeve moved by shape memory alloys (SMA) springs. In the MR clutch, the magnet can move under the effect of a passive pneumatic system. The magnetic field in the fluid varies with the magnets displacement and two steady positions are possible: the engaged clutch (ON) and the disengaged clutch (OFF). The torque in the ON configuration is high enough to drive the vacuum pump during normal operating conditions, whereas the low torque value in the OFF condition guarantees power saving up to 150 W. In particular operating conditions (i.e. at low environmental temperatures) the torque necessary to start the vacuum pump may exceed the maximum transmissible torque of the MR clutch. For this reason a sliding spline sleeve, led by two SMA springs which counteract the force of two traditional springs was developed. A dummy plain sliding sleeve with SMA and conventional springs was numerically developed and tested. The fairly good agreement of the results confirmed the feasibility of the combined SMA/MR device.

Martensitic Transformation in Submicron Cu-Al-Ni Pillar

2013 ◽  
Vol 1581 ◽  
Author(s):  
Lifeng Liu ◽  
Yumei Zhou ◽  
Lan Lv
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Single Crystal ◽  
Shape Memory ◽  
Sample Size ◽  
Small Scale ◽  
Bulk Materials ◽  
Stress Curve ◽  
Strain Stress

ABSTRACTThe transformation plateau on the strain-stress curve is the characteristic of superelasticity of bulk shape memory alloys upon tension/compression loading. However, recent studies show that such transformation plateau is hard to see when the sample size of shape memory alloys decreases to submicrons. In order to see what happened in such small scale samples during loading, in-situ compression test has been done with single crystal Cu-14.2Al-4.0Ni (wt %) submicron pillars. Our in-situ observation during compression demonstrates that the stress-induced martensitic transformation indeed occurs in submicron pillars, but is not suppressed. Furthermore, the transformation proceeds in a sequential nucleation-growth-nucleation dominated mode, but not the transient way like that in bulk materials. As a result, the stress keeps increasing throughout the transformation and no obvious transformation plateau can be detected. However, the underlying reason for such contrast transformation behaviors between our submicron pillars and bulk materials still needs further investigation.

Steady State Crack Growth in Shape Memory Alloys

2013 ◽  
Author(s):  
Selcuk Hazar ◽  
Wael Zaki ◽  
Ziad Moumni ◽  
Gunay Anlas
Keyword(s):  
Steady State ◽  
Stress Distribution ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Crack Growth ◽  
Crack Tip ◽  
Reverse Transformation ◽  
Small Scale ◽  
Local Algorithms ◽  
Non Local

Shape memory alloys experience phase transformation from austenite to martensite around crack tip. When the crack advances, martensitic transformation occurs at the tip and the energy that goes into transformation results in stable crack growth like in the case of plastic deformation. In literature, there are studies on steady-state crack growth in elasto-plastic materials with small scale yielding around crack tip that use stationary movement methods similar to non-local algorithms. In this work, Mode I steady-state crack growth in an edge cracked Nitinol plate is modeled using a non-local stationary movement method. The Zaki-Moumni (ZM) constitutive model is utilized for this purpose. The model is implemented in ABAQUS by means of a user-defined material subroutine (UMAT) to determine transformation zones around the crack tip. Steady-state crack growth is first simulated without considering reverse transformation to calculate the effect of transformation on stress distribution in the wake region, then reverse transformation is taken into account. Stress distribution and transformation regions calculated for both cases are compared to results obtained for the case of a static crack.

Application of SMA Actuators to Spacesuit Glove Mobility

2012 ◽  
Author(s):  
Grant Atkinson ◽  
Kenton Kirkpatrick ◽  
Darren Hartl ◽  
John Valasek
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Small Scale ◽  
Space Suit ◽  
Element Analysis ◽  
Advantages And Disadvantages ◽  
Glove Finger ◽  
Specific Shape ◽  
Actuator Design

A common problem with space suit systems is overly rigid gloves that resist astronaut finger motion and gripping. In this paper, the design of a mechanism is considered that exploits the small-scale nature of shape memory alloys for actuating glove fingers to assist hand gripping. The design problem is introduced by considering the objectives, constraints, and variables relevant to a spacesuit glove actuator design. Advantages and disadvantages of shape memory alloys for this application are presented. The selection of a specific shape memory alloy composition is considered, as well as specimen dimensions and connection configuration, based on ergonomic considerations. Mechanism actuation was then simulated using finite element analysis of a simulated glove-finger-actuator assembly. The results of this paper show that the designed shape memory alloy mechanism is feasible for assisting astronaut hand gripping.

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