Note: Frictional Effects in Compressional Deformation of Gelatin and Starch Gels and Comparison of Material Response in Simple Shear, Torsion, and Lubricated Uniaxial Compression

1985 ◽  
Vol 29 (1) ◽  
pp. 103-108 ◽  
Author(s):  
E. B. Bagley ◽  
D. D. Christianson ◽  
W. J. Wolf
Keyword(s):  
Uniaxial Compression ◽  
Simple Shear ◽  
Material Response ◽  
Compressional Deformation ◽  
Starch Gels ◽  
Frictional Effects

scholarly journals Constitutive modeling of nonlinear strain and time dependent behaviors of ballistic gelatin at low strain rates

Mechanika ◽  
2020 ◽  
Vol 26 (3) ◽  
pp. 191-196
Author(s):  
Li Liu ◽  
Chuan Ding ◽  
Qianqian Lu
Keyword(s):  
Uniaxial Compression ◽  
Simple Shear ◽  
Constitutive Modeling ◽  
Time Dependent ◽  
Strain Rates ◽  
Compression Tests ◽  
Shear Tests ◽  
Energy Potential ◽  
Nonlinear Strain ◽  
Ballistic Gelatin

The present study is concentrated in constitutive modeling of ballistic gelatin at low strain rates. The relaxation tests, simple shear tests at strain rates ranging from 0.0005/s to 1.245/s and uniaxial compression tests at engineering strain rates ranging from 0.004/s to 0.208/s are carried out, and nonlinear strain and time dependent behaviors of ballistic gelatin are observed. A visco-hyperelastic model is proposed based on the Prony series and the reduced polynomial strain energy potential. The material parameters are obtained by fitting to the data of the relaxation and simple shear tests and validated by predicting the compression stress-strain relationships in the uniaxial compression tests. The nonlinear strain and time dependent behaviors of ballistic gelatin are well captured by the model proposed.

scholarly journals Deformation rates in combined compression and shear for ice which is initially isotropic and after the development of strong anisotropy

1996 ◽  
Vol 23 ◽  
pp. 247-252 ◽  
Author(s):  
Li Jun ◽  
T.H Jacka ◽  
W.F. Budd
Keyword(s):  
Shear Stress ◽  
Steady State ◽  
Stress State ◽  
Strain Rate ◽  
Shear Strain ◽  
Uniaxial Compression ◽  
Simple Shear ◽  
Strain Rates ◽  
Shear Strain Rate ◽  
State Dependent

Laboratory-prepared fine-grained, initially isotropic polycrystalline ice samples were deformed under conditions of simple shear with simultaneous uniaxial compression at a constant temperature of −2.0°C. The aim was to investigate the effects of stress configuration on the flow rate of initially isotropic ice and on ice with subsequent stress and strain-induced anisotropy. Experiments were carried out for various combinations of shear and compression with shear stress ranging from 0 to 0.49 MPa and compressive stress ranging from 0 to 0.98 MPa, but such that for every experiment the octahedral shear stress was 0.4 MPa.The strain curves resulting from the experiments clearly exhibit minimum strain rates while the ice is still isotropic, and steady-state tertiary strain rates along with the development of steady-state anisotropic fabric patterns. With constant octahedral stress (root-mean-square of the principal stress deviators), the minimum octahedral shear-strain rate has no dependence on stress configuration. This result supports the hypothesis that the flow of isotropic ice is dependent only on the second invariant of the stress tensor. This fundamental assumption has been used to provide a general description of ice-flow behaviour independent of the stress configuration (e.g. Nye, 1953; Glen, 1958; Budd, 1969).For the tertiary flow of anisotropic ice, the octahedral strain rate is stress-state dependent as a consequence of the developed crystal-orientation fabric, which is also stress-state dependent, and which develops with strain and rotation. The present tests indicate that the enhancement factor for steady-state tertiary octahedral shear-strain rate depends on the shear or compression fraction and varies from about 10 for simple shear (with zero compression) to about 3 for uniaxial compression (with zero shear).

scholarly journals Deformation rates in combined compression and shear for ice which is initially isotropic and after the development of strong anisotropy

1996 ◽  
Vol 23 ◽  
pp. 247-252 ◽  
Author(s):  
Li Jun ◽  
T.H Jacka ◽  
W.F. Budd
Keyword(s):  
Shear Stress ◽  
Steady State ◽  
Stress State ◽  
Strain Rate ◽  
Shear Strain ◽  
Uniaxial Compression ◽  
Simple Shear ◽  
Strain Rates ◽  
Shear Strain Rate ◽  
State Dependent

Laboratory-prepared fine-grained, initially isotropic polycrystalline ice samples were deformed under conditions of simple shear with simultaneous uniaxial compression at a constant temperature of −2.0°C. The aim was to investigate the effects of stress configuration on the flow rate of initially isotropic ice and on ice with subsequent stress and strain-induced anisotropy. Experiments were carried out for various combinations of shear and compression with shear stress ranging from 0 to 0.49 MPa and compressive stress ranging from 0 to 0.98 MPa, but such that for every experiment the octahedral shear stress was 0.4 MPa. The strain curves resulting from the experiments clearly exhibit minimum strain rates while the ice is still isotropic, and steady-state tertiary strain rates along with the development of steady-state anisotropic fabric patterns. With constant octahedral stress (root-mean-square of the principal stress deviators), the minimum octahedral shear-strain rate has no dependence on stress configuration. This result supports the hypothesis that the flow of isotropic ice is dependent only on the second invariant of the stress tensor. This fundamental assumption has been used to provide a general description of ice-flow behaviour independent of the stress configuration (e.g. Nye, 1953; Glen, 1958; Budd, 1969). For the tertiary flow of anisotropic ice, the octahedral strain rate is stress-state dependent as a consequence of the developed crystal-orientation fabric, which is also stress-state dependent, and which develops with strain and rotation. The present tests indicate that the enhancement factor for steady-state tertiary octahedral shear-strain rate depends on the shear or compression fraction and varies from about 10 for simple shear (with zero compression) to about 3 for uniaxial compression (with zero shear).

scholarly journals The tertiary creep of polycrystalline ice: experimental evidence for stress-dependent levels of strain-rate enhancement

2012 ◽  
Vol 58 (208) ◽  
pp. 301-314 ◽  
Author(s):  
Adam Treverrow ◽  
William F. Budd ◽  
Tim H. Jacka ◽  
Roland C. Warner
Keyword(s):  
Strain Rate ◽  
Uniaxial Compression ◽  
Simple Shear ◽  
Relative Magnitude ◽  
Constant Factor ◽  
Tertiary Creep ◽  
Shear Stresses ◽  
Rate Enhancement ◽  
Polycrystalline Ice ◽  
Stress Dependent

AbstractLaboratory creep deformation experiments have been conducted on initially isotropic laboratory-made samples of polycrystalline ice. Steady-state tertiary creep rates, , were determined at strains exceeding 10% in either uniaxial-compression or simple-shear experiments. Isotropic minimum strain rates, , determined at ˜1 % strain, provide a reference for comparing the relative magnitude of tertiary creep rates in shear and compression through the use of strain-rate enhancement factors, E, defined as the ratio of corresponding tertiary and isotropic minimum creep rates, i.e. . The magnitude of strain-rate enhancement in simple shear was found to exceed that in uniaxial compression by a constant factor of 2.3. Results of experiments conducted at octahedral shear stresses of to = 0.040.80 MPa indicate a creep power-law stress exponent of n = 3 for isotropic minimum creep rates and n = 3.5 for tertiary creep rates. The difference in stress exponents for minimum and tertiary creep regimes can be interpreted as a t0 stress-dependent level of strain-rate enhancement, i.e. .The implications of these results for deformation in complex multicomponent stress configurations and at stresses below those used in the current experiments are discussed.

Simple Shear Testing of Parallel-Fibered Planar Soft Tissues

2000 ◽  
Vol 123 (2) ◽  
pp. 170-175 ◽  
Author(s):  
John C. Gardiner ◽  
Jeffrey A. Weiss
Keyword(s):  
Aspect Ratio ◽  
Simple Shear ◽  
Soft Tissues ◽  
Central Area ◽  
Fiber Material ◽  
Transversely Isotropic ◽  
Uniform Strain ◽  
Fiber Direction ◽  
Material Response ◽  
Test Configuration

The simple shear test may provide unique information regarding the material response of parallel-fibered soft tissues because it allows the elimination of the dominant fiber material response from the overall stresses. However, inhomogeneities in the strain field due to clamping and free edge effects have not been documented. The finite element method was used to study finite simple shear of simulated ligament material parallel to the fiber direction. The effects of aspect ratio, clamping prestrain, and bulk modulus were assessed using a transversely isotropic, hyperelastic material model. For certain geometries, there was a central area of uniform strain. An aspect ratio of 1:2 for the fiber to cross-fiber directions provided the largest region of uniform strain. The deformation was nearly isochoric for all bulk moduli indicating this test may be useful for isolating solid viscoelasticity from interstitial flow effects. Results suggest this test can be used to characterize the matrix properties for the type of materials examined in this study, and that planar measurements will suffice to characterize the strain. The test configuration may be useful for the study of matrix, fiber-matrix, and fiber-fiber material response in other types of parallel-fibered transversely isotropic soft tissues.

Behavior of corn, wheat and rice starch gels in uniaxial compression

1990 ◽  
Vol 4 (4) ◽  
pp. 289-298 ◽  
Author(s):  
D.D. Christianson ◽  
E.B. Bagley
Keyword(s):  
Uniaxial Compression ◽  
Rice Starch ◽  
Starch Gels

Application of Critical State Approach to Liquefaction Resistance of Sand–Silt Mixtures under Cyclic Simple Shear Loading

2021 ◽  
Vol 147 (3) ◽  
pp. 04020177
Author(s):  
Daniela Dominica Porcino ◽  
Theodoros Triantafyllidis ◽  
Torsten Wichtmann ◽  
Giuseppe Tomasello
Keyword(s):  
Simple Shear ◽  
Critical State ◽  
Shear Loading ◽  
Liquefaction Resistance
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