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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 299 for “"Shape Memory"”.
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NOVEL SHAPE MEMORY AND MULTI-SHAPE MEMORY POLYMERS FOR BIOMATERIAL APPLICATIONS
… natural environment. In this work, advanced shape memory polymers (SMPs) that respond to non-thermal triggers and multi-shape memory materials capable of multiple topographical transitions were developed for advanced active cell culture platforms. </p> <p> The first part of this dissertation …
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Granular Shape Memory Ceramics
Shape memory ceramics (SMCs) are burgeoning functional materials based on zirconia with a reversible, stress-inducible martensitic phase transformation. Compared to metallic shape memory alloys, SMCs have broader operating temperatures, higher critical stresses, and larger mechanical hysteresis …
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Nitinol-reinforced shape-memory polymers
Reinforced shape-memory polymers have been developed from an acrylate based thermoset shape-memory polymer and nitinol wires. A rectangular shape-memory polymer measuring approximately 1 by 2 by 0.1 inches has a ten fold increase in actuation force under three-point bending when reinforced with two …
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Shape memory ceramics in small volumes
Shape memory ceramics rely on martensitic transformations which are similar to those found in metallic shape memory materials, but ceramics offer several advantages over metals such as higher operating temperatures and larger transformation stresses. However, polycrystalline shape memory ceramics …
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Size Effects in Shape Memory Ceramics
Bulk shape memory ceramics (SMCs) are attractive for their high transformation temperatures and transformation stresses compared to shape memory metals but exhibit transformation-induced cracking due to mismatch stresses arising at the grain boundaries. Current strategies for mitigating cracking in …
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Prestressing Concrete with Shape Memory Alloy Fibers
… large, straight members. During the last decade, shape memory alloys (SMA) have become more prevalent in engineering and civil engineering applications. The shape memory effect refers to the contraction of the SMA when it is heated to its austenite phase. When a prestrain is induced in the SMA, it …
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Shape memory ceramic actuation of adaptive structures
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1995.
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Orthopaedic applications of ferromagnetic shape memory alloys
Ferromagnetic shape memory alloys (FSMAs) are a new class of magnetic field-actuated active materials with no current commercial applications. By applying a magnetic field of around 0.4 T, they can exert a stress of approximately 1.5 MPa, exhibiting a strain of up to 6%. This thesis evaluates their …
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Shape Memory Alloys for small scale actuation
Shape Memory Alloys (SMAs), materials that can undergo a fully recoverable strain change due to a thermal cycle, and which can be produced in a form that is superelastic are only utilized limitedly. In this thesis, I investigated the relationship between the material properties of shape memory …
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Advancing Architecture through Shape Memory Alloy Actuators
This thesis explores the integration of Shape Memory Alloy (SMA) actuators into architectural design, proposing a comprehensive knowledge framework that bridges material science, responsive technologies, and architectural theory. Motivated by the ontological and experiential implications of kinetic …
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The constitutive modeling of shape memory alloys
… thermomechanical constitutive model for shape memory alloys based on basic concepts of thermodynamics and phase transformation kinetics. Compared with other developed constitutive relations, this thermomechanical constitutive relation not only reflects the physical essence of shape memory …
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Functionalized Shape Memory Alloy Microfilament Twisted Yarn Structures
… devices. Of the smart material technologies, shape memory alloys (SMA) exhibit significant strain recoverability, large actuation deformations and forces, and multipurpose damping abilities through thermally dependent solid-state phase transformations. Monofilament-based SMA systems have …
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Transmission Electron Microscopy Studies In Shape Memory Alloys
… with strain recovery that results in the shape memory effect. Ternary elemental additions such as Fe can additionally introduce an intermediate rhombohedral (R) phase between the cubic and monoclinic phase transformation. This work was initiated with the broad objective of connecting the …
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4D Printing Shape Memory Polymers for Biomedical Applications
… development of 3D printing techniques using shape-memory polymers (SMPs) hascreated potentials for creating dynamic, three-dimensional structures that can be produced rapidly and be customized for specific and complex architectures. These qualities have made 3D printing a popular fabrication …
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Shape Memory Phenomena in Copper - Zinc Single Crystals
Made available in DSpace on 2014-12-14T16:00:32Z (GMT). No. of bitstreams: 1 7709173.pdf: 8906145 bytes, checksum: dc625a5ebb89f11544f0d72be773aaef (MD5) Previous issue date: 1976
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Droplet manipulation on structured shape memory polymer surface
… achieve. In this work, we present a structured shape memory polymer (SMP) surface which shows dynamically tunable surface wettability through changeable surface morphology in order to manipulate water droplets. The structured SMP surface involves a SMP pillar array consisting of nanotextured …
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Segmented binary control of shape memory actuator systems
A new approach to the design and control of shape memory alloy (SMA) actuators is presented. SMA wires are divided into many segments and their thermal states are controlled individually as a group of finite state machines. Instead of driving a current to the entire SMA wire and controlling the …
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A novel binary actuator using shape memory alloy
… of the martensitic transformation of Nitinol, a Shape Memory Alloy (SMA), to generate the actuation force. A compliant bistable mechanism provides the restoring force that pre- strains the martensitic Nitinol, and thus makes the actuator binary. Binary actuation alleviates some of the problems …
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Using shape memory alloy as dampers : design methodology
Many shape memory alloy (SMA) material models have been proposed in the literature, but most are suited only to forward analysis and not to design. This project proposes a generalized friction element, the lambda box, to model the stress-strain curve of SMA during pseudoelasticity. Simulation is …
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Shape memory materials : crystallographic texture and its consequences
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2000.
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