scholarly journals An Analysis of the Corrections to the Normal Force Response for the Cone and Plate Geometry in Single‐Step Stress Relaxation Experiments

1989 ◽  
Vol 33 (1) ◽  
pp. 69-91 ◽  
Author(s):  
Louis J. Zapas ◽  
Gregory B. McKenna ◽  
Astrid Brenna
Keyword(s):  
Stress Relaxation ◽  
Normal Force ◽  
Single Step ◽  
Force Response ◽  
Relaxation Experiments ◽  
Plate Geometry

Stress Relaxation in Combined Torsion-Tension

1970 ◽  
Vol 37 (1) ◽  
pp. 53-60 ◽  
Author(s):  
W. Goldberg ◽  
G. Lianis
Keyword(s):  
Stress Relaxation ◽  
Constitutive Equation ◽  
Constitutive Relation ◽  
Axial Force ◽  
Single Step ◽  
Tension Stress ◽  
Simple Material ◽  
Theoretical Predictions ◽  
Fluid Theory ◽  
Relaxation Experiments

In this paper we briefly examine the form of the isothermal constitutive relation of an isotropic simple material under stress-relaxation conditions. We then compare the predictions of the Signorini form of the Bernstein, Kearsley, Zapas elastic fluid theory and the Lianis constitutive equation for single-step stress-relaxation histories and show that they are identical. Using these theories, we develop theoretical expressions for the torque and axial force in combined torsion-tension stress relaxation. Experiments were performed on samples of an SBR polymer, and the observed response is compared with theoretical predictions.

The Effect of Overshooting the Target Strain on Estimating Viscoelastic Properties From Stress Relaxation Experiments

2004 ◽  
Vol 126 (6) ◽  
pp. 844-848 ◽  
Author(s):  
Jonathan A. Gimbel ◽  
Joseph J. Sarver ◽  
Louis J. Soslowsky
Keyword(s):  
Stress Relaxation ◽  
Single Step ◽  
Strain History ◽  
Estimation Of Parameters ◽  
Ramp Rate ◽  
Relaxation Experiment ◽  
Curve Fit ◽  
Target Strain ◽  
Linear Viscoelastic ◽  
Relaxation Experiments

Background: Tendon’s mechanical behaviors have frequently been quantified using the quasi-linear viscoelastic (QLV) model. The QLV parameters are typically estimated by fitting the model to a single-step stress relaxation experiment. Unfortunately, overshoot of the target strain occurs to some degree in most experiments. This has never been formally investigated even though failing to measure, minimize, or compensate for overshoot may cause large errors in the estimation of parameters. Therefore, the objective of this study was to investigate the effect of overshoot on the estimation of QLV parameters. Method of approach: A simulated experiment was first performed to quantify the effect of different amounts of overshoot on the estimated QLV parameters. Experimental data from tendon was then used to determine if the errors associated with overshoot could be reduced when a direct fit is used (i.e., the actual strain history was used in the curve fit). Results: We found that both the elastic and viscous QLV parameters were incorrectly estimated if overshoot was not properly accounted for in the fit. Furthermore, the errors associated with overshoot were partially reduced when overshoot was accounted for using a direct fit. Conclusions: A slow ramp rate is recommended to limit the amount of overshoot and a direct fit is recommended to limit the errors associated with overshoot, although other approaches such as adjusting the control system to limit overshoot could also be utilized.

On the inference of viscoelastic constants from stress relaxation experiments

2019 ◽  
Vol 24 (1) ◽  
pp. 1-24 ◽  
Author(s):  
Kumar Vemaganti ◽  
Sandeep Madireddy ◽  
Sayali Kedari
Keyword(s):  
Stress Relaxation ◽  
Relaxation Experiments ◽  
Viscoelastic Constants

Study on Nonlinear Viscoelastic Properties of Asphalt Mixture Based on Stress Relaxation Test

2014 ◽  
Vol 563 ◽  
pp. 48-52
Author(s):  
Lei Chen ◽  
Zhi Xin Yu ◽  
Wei Ping Cui ◽  
Li Juan Qin
Keyword(s):  
Stress Relaxation ◽  
Asphalt Mixture ◽  
Viscoelastic Behavior ◽  
Exponential Model ◽  
Relaxation Test ◽  
Asphalt Binders ◽  
Stress Relaxation Test ◽  
Nonlinear Viscoelastic ◽  
Low Temperature Cracking ◽  
Relaxation Experiments

Development of normal stress in the direction perpendicular to the asphalt mixture is an important feature of the nonlinear viscoelastic behavior of asphalt binders. In this paper, this phenomenon was studied with the help of stress-relaxation experiments in torsion.  Results indicate that stress relaxation test by controlling strain could be used to evaluate the stress relaxation ability of asphalt mixture. With the aging degree of asphalt mixtures increased, the low temperature cracking resistance got worse; the higher the temperature is, the faster the stress relaxed; the smaller the initial strain, the worse the stress relaxation ability also. The viscoelasticity of asphalt mixture could be simulated by exponential model fractional and the experiments well supported the modeling results.

A comparison study of athletic kinesio tapes and structural cloth tapes applied to address biomechanical injuries and muscle stabilization

2020 ◽  
pp. 175433712093011
Author(s):  
Declan Shannon ◽  
Brian J Love
Keyword(s):  
Stress Relaxation ◽  
Maximum Stress ◽  
Compressive Force ◽  
Element Model ◽  
Comparison Study ◽  
Zener Model ◽  
Static Tensile ◽  
Relaxation Experiments ◽  
Viscoelastic Modeling

Quasi-static tensile and stress relaxation experiments were performed on several cloth-based and segmented elastomeric tapes, and the results were analyzed using viscoelastic models. The cloth tape modulus of elasticity was ∼340 MPa, while those of the kinesio tapes ranged from ∼15 to 20 MPa. The cloth tapes was also stronger and more brittle. Viscoelastic modeling of the stress relaxation behavior was done using a Zener model for the cloth tapes and a 5-element model for the kinesio tapes. The cloth tape relaxed by ∼20%, while the kinesio tapes relaxed by ∼40% of the applied maximum stress in approximately 300-s as demonstrated by viscoelastic modeling and constant strain experiments. The overall amount of long-term compressive force delivered by kinesio tapes might be inadequate for some applications, but they are more forgiving in how they are deployed.

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