Thermal Stresses in a Multilayered Anisotropic Medium With Interface Thermal Resistance

1995 ◽  
Vol 62 (3) ◽  
pp. 810-811 ◽  
Author(s):  
T. C. Chen ◽  
H. I. Jang
Keyword(s):  
Thermal Resistance ◽  
Anisotropic Medium ◽  
Thermal Stresses ◽  
Complete Solution ◽  
Thermal Contact ◽  
Plane Deformation ◽  
Numerical Illustration ◽  
Contact Conditions ◽  
Interface Thermal Resistance ◽  
Anisotropic Slab

This note is concerned with thermoelastic analysis of a multilayered anisotropic medium under the state of generalized plane deformation with interlayer thermal contact resistance. The powerful flexibility/stiffness matrix method is adopted here to obtain the complete solution of the entire layered medium by introducing the thermal and mechanical boundary and layer interface conditions including interlayer imperfect thermal contact conditions. As a numerical illustration, the effects of interlayer thermal resistance on the distributions of temperatures and thermal stresses in a laminated anisotropic slab subjected to a uniform surface temperature rise are presented.

Thermal Stresses in a Multilayered Anisotropic Medium

1991 ◽  
Vol 58 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
Surot Thangjitham ◽  
Hyung Jip Choi
Keyword(s):  
Anisotropic Medium ◽  
Thermal Stresses ◽  
Layered Medium ◽  
Complete Solution ◽  
Plane Deformation ◽  
Transversely Isotropic ◽  
Thermoelasticity Problem ◽  
Numerical Illustration ◽  
Anisotropic Slab ◽  
The Fourier Transform

A steady-state thermoelasticity problem of a multilayered anisotropic medium under the state of generalized plane deformation is considered in this paper. By utilizing the Fourier transform technique, the general solutions of thermoelasticity for layers with transversely isotropic, orthotropic, and monoclinic properties are derived. The complete solution of the entire layered medium is then obtained through introducing the thermal and mechanical boundary and layer interface conditions. This is accomplished via the flexibility/stiffness matrix method. As a numerical illustration, the distributions of temperature and thermal stresses in a laminated anisotropic slab subjected to a uniform surface temperature rise are presented for various stacking sequences of fiber-reinforced layers.

Transient Thermal Stresses in a Multilayered Anisotropic Medium

1995 ◽  
Vol 62 (4) ◽  
pp. 1067-1069 ◽  
Author(s):  
Tei-Chen Chen ◽  
Horng-I Jang ◽  
Ampere A. Tseng
Keyword(s):  
Anisotropic Medium ◽  
Thermal Stresses ◽  
Layered Medium ◽  
Complete Solution ◽  
Plane Deformation ◽  
Thermoelasticity Problem ◽  
Numerical Illustration ◽  
Anisotropic Slab ◽  
Transient Thermal ◽  
Transform Domains

A transient thermoelasticity problem of a multilayered anisotropic medium under the state of generalized plane deformation is considered in this note. The flexibility/stiffness matrix method is adopted here to obtain the complete solution of the entire layered medium by introducing the thermal and mechanical boundary and layer interface conditions in the Fourier and Laplace transform domains. As a numerical illustration, the distributions of transient temperatures and thermal stresses in a laminated anisotropic slab subjected to a uniform surface temperature rise are presented for some stacking sequences of fiber-reinforced layers.

Measurement of Interface Thermal Resistance With Neutron Diffraction

2013 ◽  
Vol 136 (3) ◽  
Author(s):  
Seung-Yub Lee ◽  
Harley Skorpenske ◽  
Alexandru D. Stoica ◽  
Ke An ◽  
Xun-Li Wang ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Thermal Resistance ◽  
Thermal Contact ◽  
Ambient Air ◽  
Material Interfaces ◽  
Oak Ridge ◽  
Spatially Resolved ◽  
Interface Thermal Resistance ◽  
Rotating Systems ◽  
Aluminum Plates

A noncontact, nondestructive neutron diffraction technique for measuring thermal resistance of buried material interfaces in bulk samples, inaccessible to thermocouple measurements, is described. The technique uses spatially resolved neutron diffraction measurements to measure temperature, and analytical or numerical methods to calculate the corresponding thermal resistance. It was tested at the VULCAN instrument of the Spallation Neutron Source, Oak Ridge National Laboratories on a stack of three 6061 alloy aluminum plates (heat-source, middle-plate, and heat-sink), held in dry thermal contact, at low pressure, in ambient air. The results agreed with thermocouple-based measurements. This technique is applicable to all crystalline materials and most interface configurations, and it can be used for the characterization of thermal resistance across interfaces in actual engineering parts under nonambient conditions and/or in moving/rotating systems.

Nonlinear Time-Dependent Thermoelastic Response in a Multilayered Anisotropic Medium

2002 ◽  
Vol 69 (4) ◽  
pp. 556-563
Author(s):  
T.-C. Chen ◽  
S.-J. Hwang ◽  
C.-Q. Chen
Keyword(s):  
Anisotropic Medium ◽  
Material Properties ◽  
Thermal Stresses ◽  
Plane Deformation ◽  
Time Dependent ◽  
Temperature Dependent ◽  
Kirchhoff Transformation ◽  
The Laplace Transform ◽  
Thermoelastic Response ◽  
Transform Domains

A time-dependent nonlinear thermoelastic problem of a multilayered anisotropic medium with a certain specific form of temperature-dependent material properties in generalized plane deformation is analyzed by flexibility/stiffness matrix technique in the article. The closed-form general solutions of temperature, displacements, and stresses can then be obtained in the Fourier and the Laplace transform domains by using the technique of Kirchhoff transformation. The effects of temperature-dependent material properties on the distributions of temperature and thermal stresses are also calculated and discussed.

A Technique for Interface Thermal Resistance Measurements Between a Nanoelectrode and a Substrate Using the 3ω Method

2008 ◽  
Author(s):  
Youngsuk Son ◽  
Monalisa Mazumder ◽  
Theodorian Borca-Tasciuc
Keyword(s):  
Thermal Resistance ◽  
Energy Flow ◽  
Thermoelectric Devices ◽  
3Ω Method ◽  
Interface Thermal Resistance ◽  
Fundamental Understanding ◽  
Nanoscale Interfaces ◽  
Low Dimensional

Developing a fundamental understanding regarding energy flow across nanoscale interfaces is critical in realizing viable nanoelectronics device systems and efficient low-dimensional thermoelectric devices. This work presents investigations of the interface thermal resistance (ITR) in a nanoelectrode-on-substrate system using the DC heating as well as the 3ω method.

scholarly journals Test Rig for Applied Experimental Investigations of the Thermal Contact Resistance at the Blade-Rotor-Connection in a Steam Turbine

2019 ◽  
Vol 141 (2) ◽  
Author(s):  
Dennis Toebben ◽  
Xavier E. R. de Graaf ◽  
Piotr Luczynski ◽  
Manfred Wirsum ◽  
Wolfgang F. D. Mohr ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Steam Turbine ◽  
Contact Pressure ◽  
Rotational Speed ◽  
Thermal Contact Resistance ◽  
Thermal Stresses ◽  
Thermal Contact ◽  
Experimental Investigations ◽  
Molybdenum Steel ◽  
Bottle Neck

Recent studies have shown that in a prewarming, respectively, warm-keeping operation of a steam turbine, the blades and vanes transport most of the heat to the thick-walled casing and rotor. Thereby, a thermal bottle-neck arises at the connection between the blade root and the rotor. The thermal contact resistance (TCR) at these interfaces affects the temperature distribution and thus the thermal stresses in the rotor. The present paper introduces an experimental setup, which is designed to quantify the TCR at the blade-rotor-connection of a steam turbine. An uncertainty analysis is presented, which proves that the average measurement uncertainties are less than one percent. The experiments especially focus on the investigation of the contact pressure, which is a function of the rotational speed. Therefore, the results of several steady-state measurements under atmospheric and evacuated atmosphere using a high temperature-resistant chromium-molybdenum steel are presented. For the evaluation of the TCR, a numerical model of the specimen is developed in addition to a simplified 1D approach. The results show a significantly increasing TCR with decreasing contact pressure, respectively, rotational speed.

Development of a Compliant Nanothermal Interface Material

2011 ◽  
Author(s):  
David Shaddock ◽  
Stanton Weaver ◽  
Ioannis Chasiotis ◽  
Binoy Shah ◽  
Dalong Zhong
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Thermal Stresses ◽  
Performance Testing ◽  
High Thermal Conductivity ◽  
Thermal Interface Material ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Bondline Thickness ◽  
Interface Materials

The power density requirements continue to increase and the ability of thermal interface materials has not kept pace. Increasing effective thermal conductivity and reducing bondline thickness reduce thermal resistance. High thermal conductivity materials, such as solders, have been used as thermal interface materials. However, there is a limit to minimum bondline thickness in reducing resistance due to increased fatigue stress. A compliant thermal interface material is proposed that allows for thin solder bondlines using a compliant structure within the bondline to achieve thermal resistance <0.01 cm2C/W. The structure uses an array of nanosprings sandwiched between two plates of materials to match thermal expansion of their respective interface materials (ex. silicon and copper). Thin solder bondlines between these mating surfaces and high thermal conductivity of the nanospring layer results in thermal resistance of 0.01 cm2C/W. The compliance of the nanospring layer is two orders of magnitude more compliant than the solder layers so thermal stresses are carried by the nanosprings rather than the solder layers. The fabrication process and performance testing performed on the material is presented.

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