A Device for Evaluating the Multiaxial Finite Strain Thermomechanical Behavior of Elastomers and Soft Tissues

1999 ◽  
Vol 67 (3) ◽  
pp. 465-471 ◽  
Author(s):  
E. M. Ortt ◽  
D. J. Doss ◽  
E. Legall ◽  
N. T. Wright ◽  
J. D. Humphrey
Keyword(s):  
Thermal Diffusivity ◽  
Plane Stress ◽  
Finite Strain ◽  
Soft Tissues ◽  
Polymeric Materials ◽  
Thermomechanical Behavior ◽  
Finite Deformations ◽  
Out Of Plane ◽  
Computer Controlled ◽  
Stretch Response

Described here is the design and development of a computer-controlled device capable of measuring the finite strain thermomechanical behavior of a general class of polymeric materials including elastomers and biological soft tissues. The utility of this device for thermoelastic and thermophysical investigations is demonstrated by the measurement of the in-plane stress-stretch response and in-plane and out-of-plane components of thermal diffusivity of neoprene rubber undergoing finite deformations.[S0021-8936(00)01603-2]

Investigation of the impact of externally applied out-of-plane stress on Ferroelectric FET

2021 ◽  
pp. 1-1
Author(s):  
Yefan Liu ◽  
Sergiu Clima ◽  
Gaspard Hiblot ◽  
Philippe Matagne ◽  
Mihaela Loana Popovici ◽  
...  
Keyword(s):  
Plane Stress ◽  
Out Of Plane ◽  
The Impact

scholarly journals Phonon hydrodynamics and ultrahigh–room-temperature thermal conductivity in thin graphite

Science ◽  
2020 ◽  
Vol 367 (6475) ◽  
pp. 309-312 ◽  
Author(s):  
Yo Machida ◽  
Nayuta Matsumoto ◽  
Takayuki Isono ◽  
Kamran Behnia
Keyword(s):  
Thermal Conductivity ◽  
Thermal Diffusivity ◽  
Wide Temperature Range ◽  
Room Temperature ◽  
Phonon Dispersion ◽  
High Conductivity ◽  
Temperature Range ◽  
A Value ◽  
Out Of Plane ◽  
Intimate Link

Allotropes of carbon, such as diamond and graphene, are among the best conductors of heat. We monitored the evolution of thermal conductivity in thin graphite as a function of temperature and thickness and found an intimate link between high conductivity, thickness, and phonon hydrodynamics. The room-temperature in-plane thermal conductivity of 8.5-micrometer-thick graphite was 4300 watts per meter-kelvin—a value well above that for diamond and slightly larger than in isotopically purified graphene. Warming enhances thermal diffusivity across a wide temperature range, supporting partially hydrodynamic phonon flow. The enhancement of thermal conductivity that we observed with decreasing thickness points to a correlation between the out-of-plane momentum of phonons and the fraction of momentum-relaxing collisions. We argue that this is due to the extreme phonon dispersion anisotropy in graphite.

Bistable out-of-plane stress-mismatched thermally actuated bilayer devices with large deflection

2011 ◽  
Vol 21 (6) ◽  
pp. 065030 ◽  
Author(s):  
B A Goessling ◽  
T M Lucas ◽  
E V Moiseeva ◽  
J W Aebersold ◽  
C K Harnett
Keyword(s):  
Plane Stress ◽  
Large Deflection ◽  
Out Of Plane ◽  
Thermally Actuated ◽  
Bilayer Devices

Coupled Porohyperelastic Mass Transport (PHEXPT) Finite Element Models for Soft Tissues Using ABAQUS

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Jonathan P. Vande Geest ◽  
B. R. Simon ◽  
Paul H. Rigby ◽  
Tyler P. Newberg
Keyword(s):  
Finite Element ◽  
Mass Transport ◽  
Soft Tissues ◽  
Convective Transport ◽  
Finite Deformations ◽  
Nonlinear Material ◽  
Finite Element Models ◽  
Finite Element Software ◽  
Mobile Species ◽  
Highly Nonlinear

Finite element models (FEMs) including characteristic large deformations in highly nonlinear materials (hyperelasticity and coupled diffusive/convective transport of neutral mobile species) will allow quantitative study of in vivo tissues. Such FEMs will provide basic understanding of normal and pathological tissue responses and lead to optimization of local drug delivery strategies. We present a coupled porohyperelastic mass transport (PHEXPT) finite element approach developed using a commercially available ABAQUS finite element software. The PHEXPT transient simulations are based on sequential solution of the porohyperelastic (PHE) and mass transport (XPT) problems where an Eulerian PHE FEM is coupled to a Lagrangian XPT FEM using a custom-written FORTRAN program. The PHEXPT theoretical background is derived in the context of porous media transport theory and extended to ABAQUS finite element formulations. The essential assumptions needed in order to use ABAQUS are clearly identified in the derivation. Representative benchmark finite element simulations are provided along with analytical solutions (when appropriate). These simulations demonstrate the differences in transient and steady state responses including finite deformations, total stress, fluid pressure, relative fluid, and mobile species flux. A detailed description of important model considerations (e.g., material property functions and jump discontinuities at material interfaces) is also presented in the context of finite deformations. The ABAQUS-based PHEXPT approach enables the use of the available ABAQUS capabilities (interactive FEM mesh generation, finite element libraries, nonlinear material laws, pre- and postprocessing, etc.). PHEXPT FEMs can be used to simulate the transport of a relatively large neutral species (negligible osmotic fluid flux) in highly deformable hydrated soft tissues and tissue-engineered materials.

Cross-Sectional Profiles and Volume Reconstructions of Soft Tissues Using Laser Beam Measurements

2004 ◽  
Vol 126 (6) ◽  
pp. 796-802 ◽  
Author(s):  
Eve Langelier ◽  
Daniel Dupuis ◽  
Michel Guillot ◽  
Francine Goulet ◽  
Denis Rancourt
Keyword(s):  
Cross Sections ◽  
Soft Tissues ◽  
Optical Methods ◽  
Mechanical Contact ◽  
Cross Sectional ◽  
Collagen Matrices ◽  
Geometric Reconstruction ◽  
Computer Controlled ◽  
Beam Motion ◽  
Collimated Beam

Precise geometric reconstruction is a valuable tool in the study of soft tissues biomechanics. Optical methods have been developed to determine the tissue cross section without mechanical contact with the specimen. An adaptation of the laser micrometer developed by Lee and Woo [ASME J. Biomech. Eng., 110 (2), pp. 110–114]. is proposed in which the laser-collimated beam rotates around and moves along a fixed specimen to reconstruct its cross sections and volume. Beam motion is computer controlled to accelerate data acquisition and improve beam positioning accuracy. It minimizes time-dependent shape modifications and increases global reconstruction precision. The technique is also competent for the measurement of immersed collagen matrices.

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