Shape Memory Epoxy Foams: New Materials for Aerospace Applications

2012 ◽  
Vol 706-709 ◽  
pp. 165-172 ◽  
Author(s):  
Loredana Santo
Keyword(s):  
Shape Memory ◽  
Space Shuttle ◽  
Compression Tests ◽  
New Materials ◽  
Deployable Structures ◽  
Aerospace Application ◽  
New Class ◽  
Aerospace Applications ◽  
Foaming Process ◽  
Structural Parts

In this paper, shape memory epoxy foams, obtained by the new solid-state foaming process for thermosetting resin powder, are investigated. Foaming experiments in different configurations, compression tests, constrained stress recovery tests, and density measurements are discussed. The interesting results seem to be very promising for the aerospace application of shape memory epoxy foams as light actuators, structural parts with reduced size during shipping, and expandable/deployable structures. Finally, an attractive experiment is introduced. It is designed for the next Space Shuttle STS-134/ULF-6 in I-25/26, on April 2011, with the aim to study the behavior of this new class of materials in microgravity.

Recent Developments in the Field of Shape Memory Epoxy Foams

2014 ◽  
Vol 783-786 ◽  
pp. 2523-2530 ◽  
Author(s):  
Loredana Santo
Keyword(s):  
Shape Memory ◽  
Space Station ◽  
Heating System ◽  
Deployable Structures ◽  
New Class ◽  
Aerospace Applications ◽  
Recent Developments ◽  
The Difference ◽  
Structural Parts ◽  
Micro Gravity

Shape memory epoxy foams are a new class of materials for aerospace applications as light actuators, structural parts with reduced size during transport, and expandable/deployable structures. They were tested in an experiment onboard of the International Space Station in May 2011 (Shuttle Mission STS 134) and in April 2013, on board the BION-M1 capsule through the Soyuz-2 launch vehicle, with the aim to study the behavior in microgravity for future applications. The experiments were performed by an autonomous device which was in turn composed of control and heating system, battery pack and data acquisition system. Micro-gravity does not affect the ability of the foams to recover their shape but it poses limits for the heating system design because of the difference in heat transfer on earth and on orbit. This could be very significant for the behaviour of complex multi-functional structures in which shape memory epoxy foams are integrated. In this work, the main results of the experiments in microgravity are discussed and some results of tests on ground are shown in order to evaluate new possible developments in the field.

scholarly journals Shape Memory Composites for Self-deployable Structures in Aerospace Applications

2014 ◽  
Vol 88 ◽  
pp. 42-47 ◽  
Author(s):  
Loredana Santo ◽  
Fabrizio Quadrini ◽  
Antonio Accettura ◽  
Walter Villadei
Keyword(s):  
Shape Memory ◽  
Deployable Structures ◽  
Aerospace Applications ◽  
Shape Memory Composites

scholarly journals Thermally-Induced Shape-Memory Behavior of Degradable Gelatin-Based Networks

2021 ◽  
Vol 22 (11) ◽  
pp. 5892
Author(s):  
Axel T. Neffe ◽  
Candy Löwenberg ◽  
Konstanze K. Julich-Gruner ◽  
Marc Behl ◽  
Andreas Lendlein
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Recovery ◽  
Polymer Networks ◽  
Water Soluble ◽  
Compression Tests ◽  
Thermally Induced ◽  
Thermomechanical Process ◽  
Triple Helices

Shape-memory hydrogels (SMH) are multifunctional, actively-moving polymers of interest in biomedicine. In loosely crosslinked polymer networks, gelatin chains may form triple helices, which can act as temporary net points in SMH, depending on the presence of salts. Here, we show programming and initiation of the shape-memory effect of such networks based on a thermomechanical process compatible with the physiological environment. The SMH were synthesized by reaction of glycidylmethacrylated gelatin with oligo(ethylene glycol) (OEG) α,ω-dithiols of varying crosslinker length and amount. Triple helicalization of gelatin chains is shown directly by wide-angle X-ray scattering and indirectly via the mechanical behavior at different temperatures. The ability to form triple helices increased with the molar mass of the crosslinker. Hydrogels had storage moduli of 0.27–23 kPa and Young’s moduli of 215–360 kPa at 4 °C. The hydrogels were hydrolytically degradable, with full degradation to water-soluble products within one week at 37 °C and pH = 7.4. A thermally-induced shape-memory effect is demonstrated in bending as well as in compression tests, in which shape recovery with excellent shape-recovery rates Rr close to 100% were observed. In the future, the material presented here could be applied, e.g., as self-anchoring devices mechanically resembling the extracellular matrix.

B2 Intermetallic Compounds of Zr. New Class of the Shape Memory Alloys

1995 ◽  
Vol 05 (C8) ◽  
pp. C8-1103-C8-1108 ◽  
Author(s):  
Yu.N. Koval ◽  
G.S. Firstov ◽  
J.V. Humbeeck ◽  
L. Delaey ◽  
W.Y. Jang
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Intermetallic Compounds ◽  
New Class

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

2018 ◽  
Vol 29 (19) ◽  
pp. 3748-3757 ◽  
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.

scholarly journals Shape-Memory-Recovery Characteristics of Microcellular Foamed Thermoplastic Polyurethane

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 351
Author(s):  
Chang-Seok Yun ◽  
Joo Seong Sohn ◽  
Sung Woon Cha
Keyword(s):  
Shape Memory ◽  
Cell Density ◽  
Shape Recovery ◽  
Structural Changes ◽  
Thermoplastic Polyurethane ◽  
Testing Machine ◽  
Base Material ◽  
Memory Mechanism ◽  
Foaming Process ◽  
Dog Bone

We investigated the shape-recovery characteristics of thermoplastic polyurethane (TPU) with a microcellular foaming process (MCP). Additionally, we investigated the correlation between changes in the microstructure and the shape-recovery characteristics of the polymers. TPU was selected as the base material, and the shape-recovery characteristics were confirmed using a universal testing machine, by manufacturing dog-bone-type injection-molded specimens. TPUs are reticular polymers with both soft and hard segments. In this study, we investigated the shape-memory mechanism of foamed polymers by maximizing the shape-memory properties of these polymers through a physical foaming process. Toward this end, TPU specimens were prepared by varying the gas pressure, foaming temperature, and type of foaming gas in the batch MCP. The effects of internal structural changes were investigated. These experimental variables affected the microstructure and shape-recovery characteristics of the foamed polymer. The generated cell density changed, which affected the shape-recovery characteristics. In general, a higher cell density corresponded to a higher shape-recovery ratio.

Shape memory polymers and their composites in aerospace applications: a review

2014 ◽  
Vol 23 (2) ◽  
pp. 023001 ◽  
Author(s):  
Yanju Liu ◽  
Haiyang Du ◽  
Liwu Liu ◽  
Jinsong Leng
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymers ◽  
Aerospace Applications

Using Multiscale Modeling to Predict Material Response of Polymeric Materials

2009 ◽  
Author(s):  
Richard V. Beblo ◽  
Lisa Mauck Weiland
Keyword(s):  
Shape Memory ◽  
Multiscale Modeling ◽  
Shape Memory Polymer ◽  
Polymeric Materials ◽  
Scale Model ◽  
Molecular Formula ◽  
Thermal Stimulus ◽  
Rotational Isomeric State ◽  
New Class ◽  
Constraint Theory

Presented is a multiscale modeling method applied to light activated shape memory polymers (LASMP). LASMP are a new class of shape memory polymer (SMP) being developed for applications where a thermal stimulus is undesired. Rotational Isomeric State (RIS) theory is used to build a molecular scale model of the polymer chain yielding a list of distances between the predicted cross-link locations, or r-values. The r-values are then fit with Johnson probability density functions and used with Boltzmann statistical mechanics to predict stress as a function of strain of the phantom network. Junction constraint theory is then used to calculate the stress contribution due to interactions with neighboring chains, resulting in previously unattainable numerically accurate Young’s modulus predictions based on the molecular formula of the polymer. The system is modular in nature and thus lends itself well to being adapted for specific applications. The results of the model are presented with experimental data for confirmation of correctness along with discussion of the potential of the model to be used to computationally adjust the chemical composition of LASMP to achieve specified material characteristics, greatly reducing the time and resources required for formula development.

Sign in / Sign up

Export Citation Format

Share Document