scholarly journals Thermodynamic Relations among Isotropic Material Properties in Conditions of Plane Shear Stress

Entropy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 295
Author(s):  
Amilcare Porporato ◽  
Salvatore Calabrese ◽  
Tomasz Hueckel
Keyword(s):  
Shear Stress ◽  
Material Properties ◽  
Isotropic Material ◽  
Soil Behavior ◽  
Plane Shear ◽  
Thermal Expansion Coefficients ◽  
Shear Stress And Strain ◽  
Homogeneous Stress

We present new general relationships among the material properties of an isotropic material kept in homogeneous stress conditions with hydrostatic pressure and plane shear. The derivation is not limited to the proximity of the zero shear-stress and -strain condition, which allows us to identify the relationship between adiabatic and isothermal shear compliances (inverse of the moduli of rigidity) along with new links, among others, between isobaric and isochoric shear thermal expansion coefficients and heat capacities at constant stress and constant shear strain. Such relationships are important for a variety of applications, including the determination of constitutive equations, the characterization of nanomaterials, and the identification of properties related to earthquakes precursors and complex media (e.g., soil) behavior. The results may be useful to investigate the behavior of materials during phase transitions involving shear or in non-homogeneous conditions within a local thermodynamic equilibrium framework.

Four-Wire Bridge Measurements of van der Pauw Stress Sensors on (100) and (111) Silicon

2013 ◽  
Author(s):  
Richard C. Jaeger ◽  
Mohammad Motalab ◽  
Safina Hussain ◽  
Jeffrey C. Suhling
Keyword(s):  
Shear Stress ◽  
Normal Stress ◽  
Normal Stress Difference ◽  
Stress Difference ◽  
Plane Shear ◽  
Plane Normal ◽  
Stress Sensors ◽  
Van Der Pauw ◽  
Contact Sensors

Four-wire resistance characterization of van der Pauw stress sensors is discussed. Under the proper orientations and excitations, the output of the four-contact sensors can be shown to depend upon only the in-plane shear stress or the in-plane normal stress difference on (100) silicon. The other stress terms are cancelled out by the symmetry of the structure, and the measurements are inherently temperature compensated. In bridge-mode, each sensor requires only one measurement and produces an output voltage that is directly proportional to the shear stress or in-plane normal stress difference, and the sensitivity is 3.16 times that of the equivalent resistor sensors, just as in the normal van der Pauw mode. Experimental, theoretical, finite-difference and finite-element and simulation results are presented demonstrating the behavior of the sensor. The two sensors can be merged into one eight-contact device, or n- and p-tye sensors can be overlaid in standard IC processes. Similar results apply to sensors on (111) silicon.

Characterization of the Linear Viscoelastic Region in Suspensions of Zirconium Oxide: Cohesive Energy Obtained From the Critical Parameters

2004 ◽  
Vol 14 (3) ◽  
pp. 126-132 ◽  
Author(s):  
David Megías-Alguacil
Keyword(s):  
Shear Stress ◽  
Cohesive Energy ◽  
Zirconium Oxide ◽  
Volume Fraction ◽  
Critical Parameters ◽  
M 10 ◽  
Linear Viscoelastic ◽  
Shear Stress And Strain ◽  
Oxide Particles

Abstract The linear viscoelastic regions (L.V.R.) of suspensions of zirconium oxide particles were determined and characterized through the so-called "critical parameters". These are the values of shear-stress and strain at the crossover between the linear and the non-linear viscoelastic responses. From these magnitudes, the cohesive energy between the particles is calculated as a function of volume fraction of solids and at different electrolyte concentrations. The oscillatory measurements were carried out using a constant-stress rheometer at a fixed frequency of 1 Hz and increasing shear-stress. The suspensions cover a volume fraction range between 3% - 25% with electrolyte (sodium chloride) concentrations of 10-1 M, 10−2 M, 10−3 M and 10−5 M. Two different kinds of ZrO2 particles were used: commercially obtained -with no defined geometry- and spheres synthesized by us following the method described by Aiken, Hsu and Matijevic [1].

Rhesus Monkey Intervertebral Disk Viscoelastic Response to Shear Stress

1983 ◽  
Vol 105 (1) ◽  
pp. 51-54 ◽  
Author(s):  
B. S. Kelley ◽  
J. F. Lafferty ◽  
D. A. Bowman ◽  
P. A. Clark
Keyword(s):  
Shear Stress ◽  
Rhesus Monkey ◽  
Material Properties ◽  
Mechanical Model ◽  
Viscoelastic Model ◽  
Intervertebral Disk ◽  
Viscoelastic Response ◽  
Relaxation Functions ◽  
Experimental Strain

A viscoelastic model of the shear response of the Rhesus monkey intervertebral disk, represented by a series chain of four Kelvin units is presented. Two types of investigations are carried out to assess the validity of the model: 1) determination of material properties by comparison with experimental strain creep behavior of the disk; and 2) validation of this viscoelastic model by accurately predicting the experimental results of stress relaxation tests. The use of the series Kelvin units approach provides the first analytical mechanical model capable of predicting the creep and relaxation functions for the intervertebral disk in shear.

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