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.

On the Nonlinear Viscoelastic Behaviour of the PVC-Coated Fabric

2010 ◽  
Vol 160-162 ◽  
pp. 1476-1481 ◽  
Author(s):  
Wu Lian Zhang ◽  
Xin Ding ◽  
Xu Dong Yang
Keyword(s):  
Viscoelastic Model ◽  
Constitutive Relationship ◽  
Viscoelastic Behaviour ◽  
Viscoelastic Response ◽  
Nonlinear Parameters ◽  
Creep And Recovery ◽  
Nonlinear Viscoelastic ◽  
Coated Fabric ◽  
Nonlinear Viscoelastic Model

The nonlinear viscoelastic response of a PVC-Coated Fabric has been studied. For the needs of the present study, creep and recovery tests in tension of both the warp and the weft directions at the different stress levels were executed while measurements were made of the creep and recovery strain response of the system. For the description of the viscoelastic behaviour of the material, Schapery’s nonlinear viscoelastic model was used. For the description of the nonlinear viscoelastic response and the determination of the nonlinear parameters, a method by using a combination of analytical formulations and numerical procedures based on a modified version of Schapery’s constitutive relationship where an instantaneous plastic and a transient plastic terms were added, has been developed. The method has been successfully applied to the current tests.

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.

Response of the Intervertebral Disk of the Rhesus Monkey to P-A Shear Stress

1980 ◽  
Vol 102 (2) ◽  
pp. 137-140 ◽  
Author(s):  
S. A. Lantz ◽  
J. F. Lafferty ◽  
D. A. Bowman
Keyword(s):  
Shear Stress ◽  
Rhesus Monkey ◽  
Nucleus Pulposus ◽  
Intervertebral Disk ◽  
Stress Strain ◽  
As Stress

The relative functions of spinal elements in resisting P-A shear stress are determined from measurements of force and displacement. The response of intact, enucleate and degenerate disks are presented, as well as stress-strain characteristics of the intervertebral disk and the roles of the articular facets and the nucleus pulposus.

On the Determination of a Viscoelastic Model for Stress Analysis of Plastics

1956 ◽  
Vol 23 (3) ◽  
pp. 416-420
Author(s):  
D. R. Bland ◽  
E. H. Lee
Keyword(s):  
Stress Analysis ◽  
Viscous Flow ◽  
Viscoelastic Material ◽  
Graphical Method ◽  
Viscoelastic Model ◽  
Element Model ◽  
Viscoelastic Response ◽  
Frequency Range ◽  
Complex Compliance

Abstract A method of assessing whether or not the measured variation of complex compliance with frequency for a viscoelastic material is consistent with a four-element model is presented. The four-element model was chosen since it is relatively simple to analyze, and exhibits the three main types of viscoelastic response; namely, instantaneous elasticity, viscous flow, and delayed elasticity. If the compliance measurements are found to conform with the behavior of a four-element model over the whole or part of the frequency range studied, a graphical method of determining the model constants is presented. The significance of the application of such a model to stress analysis under transient loading is discussed.

Determination of Charge Coefficient of Piezoelectric Films Using a Combined Finite Element Model and Dynamic Loading Technique

2020 ◽  
Vol 835 ◽  
pp. 229-242
Author(s):  
Oboso P. Bernard ◽  
Nagih M. Shaalan ◽  
Mohab Hossam ◽  
Mohsen A. Hassan
Keyword(s):  
Finite Element ◽  
Dynamic Loading ◽  
Material Properties ◽  
Accurate Determination ◽  
Substrate Material ◽  
Experimental Results ◽  
Piezoelectric Composite ◽  
Piezoelectric Film ◽  
Piezoelectric Charge

Accurate determination of piezoelectric properties such as piezoelectric charge coefficients (d33) is an essential step in the design process of sensors and actuators using piezoelectric effect. In this study, a cost-effective and accurate method based on dynamic loading technique was proposed to determine the piezoelectric charge coefficient d33. Finite element analysis (FEA) model was developed in order to estimate d33 and validate the obtained values with experimental results. The experiment was conducted on a piezoelectric disc with a known d33 value. The effect of measuring boundary conditions, substrate material properties and specimen geometry on measured d33 value were conducted. The experimental results reveal that the determined d33 coefficient by this technique is accurate as it falls within the manufactures tolerance specifications of PZT-5A piezoelectric film d33. Further, obtained simulation results on fibre reinforced and particle reinforced piezoelectric composite were found to be similar to those that have been obtained using more advanced techniques. FE-results showed that the measured d33 coefficients depend on measuring boundary condition, piezoelectric film thickness, and substrate material properties. This method was proved to be suitable for determination of d33 coefficient effectively for piezoelectric samples of any arbitrary geometry without compromising on the accuracy of measured d33.

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