New approach to the description of young's modulus for highly oriented polymers. ii. Relationship between young's modulus and thermal expansion of polymers over a wide temperature range

ABSTRACTHeating to temperatures up to 500°C, gives a reduction in Young's modulus and increase in permeability of granitic rocks and it is likely that a major reason is grain boundary cracking. The cracking of grain boundary facets in polycrystalline multiphase materials showing anisotropic thermal expansion behaviour is controlled by several microstructural factors in addition to the intrinsic thermal and elastic properties. Of specific interest are the relative orientations of the two grains meeting at the facet, and the size of the facet; these factors thus introduce two statistical aspects to the problem and these are introduced to give quantitative data on crack density versus temperature. The theory is compared with experimental measurements of Young's modulus and permeability for various rocks as a function of temperature. There is good qualitative agreement, and the additional (mainly microstructural) data required for a quantitative comparison are defined.

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Out-of-Plane Thermal Expansion Coefficient and Biaxial Young’s Modulus of Sputtered ITO Thin Films

Coatings ◽

10.3390/coatings11020153 ◽

2021 ◽

Vol 11 (2) ◽

pp. 153

Author(s):

Chuen-Lin Tien ◽

Tsai-Wei Lin

Keyword(s):

Thin Films ◽

Thermal Expansion ◽

Thermal Stress ◽

Young’S Modulus ◽

Thermal Expansion Coefficient ◽

Expansion Coefficient ◽

Young's Modulus ◽

Heating Temperature ◽

Glass Substrates ◽

Ito Thin Films

This paper proposes a measuring apparatus and method for simultaneous determination of the thermal expansion coefficient and biaxial Young’s modulus of indium tin oxide (ITO) thin films. ITO thin films simultaneously coated on N-BK7 and S-TIM35 glass substrates were prepared by direct current (DC) magnetron sputtering deposition. The thermo-mechanical parameters of ITO thin films were investigated experimentally. Thermal stress in sputtered ITO films was evaluated by an improved Twyman–Green interferometer associated with wavelet transform at different temperatures. When the heating temperature increased from 30 °C to 100 °C, the tensile thermal stress of ITO thin films increased. The increase in substrate temperature led to the decrease of total residual stress deposited on two glass substrates. A linear relationship between the thermal stress and substrate heating temperature was found. The thermal expansion coefficient and biaxial Young’s modulus of the films were measured by the double substrate method. The results show that the out of plane thermal expansion coefficient and biaxial Young’s modulus of the ITO film were 5.81 × 10−6 °C−1 and 475 GPa.

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Experimental study of the effect of heating rate and environment on the young's modulus of carbon-fiber plastics in a broad temperature range

Mechanics of Composite Materials ◽

10.1007/bf00606003 ◽

1986 ◽

Vol 22 (1) ◽

pp. 19-22

Author(s):

N. V. Skvortsova

Keyword(s):

Experimental Study ◽

Carbon Fiber ◽

Young’S Modulus ◽

Heating Rate ◽

Young's Modulus ◽

Broad Temperature Range ◽

Temperature Range

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Organizing Cells Within Non-Periodic Microarchitectured Materials That Achieve Graded Thermal Expansions

Volume 2B: 41st Design Automation Conference ◽

10.1115/detc2015-46638 ◽

2015 ◽

Author(s):

Jonathan B. Hopkins ◽

Lucas A. Shaw ◽

Todd H. Weisgraber ◽

George R. Farquar ◽

Christopher D. Harvey ◽

...

Keyword(s):

Finite Element Analysis ◽

Thermal Expansion ◽

Young’S Modulus ◽

Young's Modulus ◽

Element Analysis ◽

Thermal Expansion Coefficients ◽

Large Lattice ◽

Unit Cells ◽

Expansion Coefficients ◽

Bulk Behavior

The aim of this paper is to introduce an approach for optimally organizing a variety of different unit cell designs within a large lattice such that the bulk behavior of the lattice exhibits a desired Young’s modulus with a graded change in thermal expansion over its geometry. This lattice, called a graded microarchitectured material, can be sandwiched between two other materials with different thermal expansion coefficients to accommodate their different expansions or contractions caused by changing temperature while achieving a desired uniform stiffness. First, this paper provides the theory necessary to calculate the thermal expansion and Young’s modulus of large multi-material lattices that consist of periodic (i.e., repeating) unit cells of the same design. Then it introduces the theory for calculating the graded thermal expansions of a large multimaterial lattice that consists of non-periodic unit cells of different designs. An approach is then provided for optimally designing and organizing different unit cells within a lattice such that both of its ends achieve the same thermal expansion as the two materials between which the lattice is sandwiched. A MATLAB tool is used to generate images of the undeformed and deformed lattices to verify their behavior and various examples are provided as case studies. The theory provided is also verified and validated using finite element analysis and experimentation.

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