Relationship Between Dilatancy, Stresses and Plastic Dissipation in a Granular Material with Rigid Grains

1992 ◽  
Vol 291 ◽  
Author(s):  
Pierre Evesque ◽  
Christian Stefani
Keyword(s):  
Experimental Data ◽  
Granular Material ◽  
Triaxial Test ◽  
Critical State ◽  
Confining Pressure ◽  
Energy Losses ◽  
Plastic Yielding ◽  
Plastic Dissipation ◽  
Triaxial Cell ◽  
Cell Test

ABSTRACTBy considering a drained cohesionless granular sample made up of rigid grains and submitted to a triaxial test, we derive an equation relating the dilatancy K, the deviatoric stress q and the confining pressure p to the energy losses D plasticdue to plastic yielding. We demonstrate that the system is contracting (K ≤ 0) at q=0, when q is increasing and that spontaneous uncontrolled yielding begins occurring when dilatancy K is maximum. We also demonstrate the existence of the characteristic state introduced by Luong and Habib and the existence of the critical state of Schofield and Wroth. We give at last a method to determine the plastic losses during a triaxial cell test using the experimental data.

scholarly journals A Method of Predicting the Energy Losses in Vaneless Diffusers of Centrifugal Compressors

1989 ◽  
Author(s):  
Huashu Dou
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Total Energy ◽  
Wall Friction ◽  
Energy Losses ◽  
Flow Conditions ◽  
Centrifugal Compressors ◽  
Flow Losses ◽  
Vaneless Diffusers ◽  
Good Agreement

The flow losses in the veneless diffusers of centrifugal compressors is investigated. It is found that the total energy loss in vaneless diffusers is a function of Bsin2 α0 when inlet flow conditions and radius ratio between inlet and outlet are given. A wall friction coefficient equation is derived and a method of predicting the total energy loss excepting mixing loss is presented. A comparison is made between results obtained from this method and experimental data generated by the author as well as data from the literature. Good agreement is obtained.

Dynamic Stress-Strain Relationship of Saturated Clay by Dynamic Triaxial Test

2011 ◽  
Vol 250-253 ◽  
pp. 3183-3186
Author(s):  
Jian Yi Yuan
Keyword(s):  
Triaxial Test ◽  
Dynamic Stress ◽  
Soft Clay ◽  
Confining Pressure ◽  
Dynamic Shear ◽  
Stress Strain ◽  
Dynamic Triaxial Test ◽  
Wide Range ◽  
Strain Relationship ◽  
Relationship Of

Subgrade diseases are exposed more and more serious with raising speed of existing railway in wide range. Fro the complexity of dynamic stress-strain relationship of soil, dynamic triaxial test was used to analyze .the dynamic mechanics behavior under cyclic train load for saturated soft clay in Yangtze Delta region. Compaction coefficient, confining pressure, dynamic shear strsss ratio, inputing stimulus and loading frequence were taken into account in test. The results show that the dynamic stress-strain curves of soil specimen are provided with prominent hysteretic characteristics and area surrounded by hysteretic curves gradually augment and slope of hysteretic curve decreases with the increase of dynamic shear train amplitude. The strong correlation exists between dynamical stress and strain.

Modified state parameter for characterizing static liquefaction of sand with fines

2009 ◽  
Vol 46 (3) ◽  
pp. 281-295 ◽  
Author(s):  
D. C. Bobei ◽  
S. R. Lo ◽  
D. Wanatowski ◽  
C. T. Gnanendran ◽  
M. M. Rahman
Keyword(s):  
Critical State ◽  
Volumetric Strain ◽  
State Parameter ◽  
Confining Pressure ◽  
Log P ◽  
Test Results ◽  
Static Liquefaction ◽  
Isotropic Consolidation ◽  
Failure Line ◽  
Soil Behaviour

An experimental study was carried out to investigate the static liquefaction behaviour of sand with a small amount of plastic and nonplastic fines. Five series of tests were conducted in drained and undrained conditions. The drained test results indicate not only that the failure line coincides with the critical state, but also that the development of volumetric strain during shearing was not sensitive to the initial confining pressure. In both isotropically and anisotropically consolidated undrained tests, a so-called “reverse behaviour” was consistently observed. The results were also interpreted in the critical state framework. The critical and steady state (CS/SS) data were found to trace along the same curve in e–log( p′) space, irrespective of the stress history and effective stress paths. A comparison between the isotropic consolidation line (ICL) and critical state (CS) curve showed that a small amount of fines can significantly change the shape and position of the ICL relative to the CS curve. Furthermore, the soil behaviour manifested in both drained and undrained shearing led to the development of a modified state parameter.

Study on Grain Breakage in Triaxial Test of Rockfill Material

2011 ◽  
Vol 261-263 ◽  
pp. 1598-1602
Author(s):  
Jia Jun Pan ◽  
Xi Bao Rao ◽  
Yong Zhen Zuo
Keyword(s):  
Sample Preparation ◽  
Triaxial Test ◽  
Large Scale ◽  
Confining Pressure ◽  
Linear Relations ◽  
Rockfill Material ◽  
Rockfill Materials ◽  
Grain Breakage

Large-scale triaxial test has been conducted on various rockfill materials in an attempt to study the degrees of grain breakage. The result has shown that, the grain breakage occurred during sample preparation can not be neglected, and to maintain the initial gradation design prior to consolidation, the gradation design shall be adjusted downwards to a certain extent accordingly before sample preparation. The breakage of large-sized grains mainly occurs on the surface, and the grain breakage and confining pressure has shown linear relations after triaxial test.

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