Effects of Back Pressure and Strain Rate Used in Triaxial Testing of Stabilized Organic Soils and Clays

2004 ◽  
Vol 27 (3) ◽  
pp. 11453 ◽  
Author(s):  
L David Suits ◽  
TC Sheahan ◽  
H Åhnberg
Keyword(s):  
Strain Rate ◽  
Back Pressure ◽  
Triaxial Testing ◽  
Organic Soils

Automatic Back-Pressure Saturation Device for Triaxial Testing

1990 ◽  
Vol 13 (2) ◽  
pp. 77
Author(s):  
PC Knodel ◽  
TL Brandon ◽  
JD Duncan ◽  
AW Cadden
Keyword(s):  
Back Pressure ◽  
Triaxial Testing

scholarly journals Triaxial Testing of Frozen Sand

1981 ◽  
Vol 27 (95) ◽  
pp. 147-155 ◽  
Author(s):  
V. R. Parameswaran ◽  
S. J. Jones
Keyword(s):  
Strain Rate ◽  
Failure Criterion ◽  
Triaxial Testing ◽  
Confined Compression ◽  
Ottawa Sand ◽  
Frozen Sand ◽  
Coulomb Failure ◽  
Coulomb Failure Criterion

AbstractTriaxial testing of frozen saturated Ottawa sand under confined compression was carried out under hydrostatic pressures varying between 0.1 and 75 MPa at a temperature of -10°C and strain-rate 7.7×10-5 s-1. Yield and failure stresses increased with increasing hydrostatic pressures up to about 40 MPa, beyond which the stresses dropped. The results are analysed according to the Mohr-Coulomb failure criterion and compared with past results in the literature.

Study on Dissipation of Excess Pore Water Pressure of Clay

2012 ◽  
Vol 174-177 ◽  
pp. 1981-1985
Author(s):  
Jian Zhong Li ◽  
Kangning Hao
Keyword(s):  
Strain Rate ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Axial Stress ◽  
Water Pressure ◽  
Pressure Ratio ◽  
Back Pressure ◽  
Creep Tests ◽  
Excess Pore Water Pressure ◽  
Excess Pore

Dissipation of excess pore water pressure of saturation clay was discussed in the paper. Monotonic loading, unloading-reloading, and creep tests of one dimensional compression were performed to study the orderliness of dissipation of excess pore water pressure. In the drained consolidated tests, strain rate was changed step by step to check the effects of excess pore water pressure on effective axial stress. Creep tests were performed in different stage of loading and unloading procedure under different effective axial stress. In order to estimate the effects of excess pore water on effective axial stress more precisely, excess pore water pressure ratio was introduced. Test results show that: (1) excess pore water pressure changed gradually as strain rate changed abruptly, while excess pore water pressure ratio changed quickly; (2) excess pore water pressure maintained constant shortly after the change of strain rate during monotonic loading tests under small strain rate; (3) excess pore water pressure may be smaller than back pressure during unloading-reloading tests, in which, excess pore water pressure ratio is negative; (4) there neutral creep existed in unloading-creep-unloading procedure. Excess pore water pressure ratio equal to 0 and excess pore water pressure maintained a constant value equal to the back pressure in neutral creep.

Triaxial Testing of Freshwater Ice at Low Confining Pressures

1991 ◽  
Vol 113 (3) ◽  
pp. 260-265 ◽  
Author(s):  
J. P. Nadreau ◽  
A. M. Nawwar ◽  
Y. S. Wang
Keyword(s):  
Compressive Strength ◽  
Strain Rate ◽  
Confining Pressure ◽  
Peak Temperature ◽  
Triaxial Testing ◽  
Brittle Transition ◽  
Freshwater Ice ◽  
Triaxial Compressive Strength ◽  
Confining Pressures ◽  
Ductile To Brittle Transition

Tests have been conducted on freshwater columnar ice samples to determine the uniaxial and triaxial compressive strength of the ice. Four parameters were varied. The confining pressure was increased up to 2.85 MPa (400 psi) in steps of 0.7 MPa (100 psi). The strain rate was varied in order to obtain the ductile to brittle transition peak. Temperature was kept mainly at −2°, with two series at −10°C and −20°C, and samples were machined with axes parallel, perpendicular or at a 45-deg angle to the direction of ice growth. The results are presented within their original context, but analyzed with reference to recent studies conducted on the multiaxial behavior of ice.

A Triaxial Testing System to Evaluate Stress-Strain Behavior of Soils for Wide Range of Strain and Strain Rate

1999 ◽  
Vol 22 (1) ◽  
pp. 44 ◽  
Author(s):  
RC Chaney ◽  
KR Demars ◽  
F Santucci de Magistris ◽  
J Koseki ◽  
M Amaya ◽  
...  
Keyword(s):  
Strain Rate ◽  
Triaxial Testing ◽  
Testing System ◽  
Stress Strain ◽  
Strain Behavior ◽  
Strain And Strain Rate ◽  
Wide Range

scholarly journals Triaxial Testing of Frozen Sand

1981 ◽  
Vol 27 (95) ◽  
pp. 147-155 ◽  
Author(s):  
V. R. Parameswaran ◽  
S. J. Jones
Keyword(s):  
Strain Rate ◽  
Failure Criterion ◽  
Triaxial Testing ◽  
Confined Compression ◽  
Ottawa Sand ◽  
Frozen Sand ◽  
Coulomb Failure ◽  
Coulomb Failure Criterion

Abstract Triaxial testing of frozen saturated Ottawa sand under confined compression was carried out under hydrostatic pressures varying between 0.1 and 75 MPa at a temperature of -10°C and strain-rate 7.7×10-5 s-1. Yield and failure stresses increased with increasing hydrostatic pressures up to about 40 MPa, beyond which the stresses dropped. The results are analysed according to the Mohr-Coulomb failure criterion and compared with past results in the literature.

Investigation on Finite Element Simulation of ECAE with Variable Back Pressure for 7075 Aluminum Alloy

2014 ◽  
Vol 904 ◽  
pp. 36-40
Author(s):  
Xian Feng Tan ◽  
Cheng Long Yu ◽  
Bao Hua Xie
Keyword(s):  
Aluminum Alloy ◽  
Strain Rate ◽  
Equal Channel Angular Extrusion ◽  
Hydrostatic Stress ◽  
Effective Strain ◽  
Back Pressure ◽  
Extrusion Force ◽  
7075 Aluminum Alloy ◽  
Effective Strain Rate ◽  
Force Transformation

The numerical simulation of equal channel angular extrusion (ECAE) with variable back pressure was researched by applying the commercial Deform-3D software, in which choosing the hard deformation materials of 7075 aluminum alloy, and comparing the traditional ECAE without back pressure process. The influence of back pressure on the mean stress and the effective strain rate in the shear deformation zone was studied. The results show that the extrusion force transformation laws were different in both load ways, with the increase of back pressure, extrusion force enhances increasingly, but the final load-time curves tended towards stability, but in ECAE without back pressure, the final load-time curves tended towards decreasing; thus the whole deformation process can be divided into different stages. In addition, the larger the absolute value of the hydrostatic stress at the corner, the more beneficial to refine grain and improve the plasticity. The back pressure makes the distribution of effective strain rate in plastic deformation area more uniform and improves the uniformity of deformation.

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