Creep Property of Reticulate Red Clay under Stepped-Load Creep Tests

2012 ◽  
Vol 446-449 ◽  
pp. 1412-1416 ◽  
Author(s):  
Jian Zhong Li ◽  
Yan Fu Cao ◽  
Ya Jun Qing
Keyword(s):  
Creep Deformation ◽  
Empirical Formula ◽  
Creep Property ◽  
Test Results ◽  
Creep Tests ◽  
Red Clay ◽  
Reticulate Red Clay ◽  
Study Test ◽  
Previous Loading

Stepped-load creep tests of undisturbed and remodeled specimens of reticulate red clay was performed in the present study. Test results and analyses of the results show that: (1) Both undisturbed and remodeled specimens showed significant creep deformation in primary loading, unloading and reloading stage, and the creep deformation of remodeled specimen is much bigger than that of undisturbed one in primary loading and reloading stage; (2) The effect of a previous loading stage on the deformation induced at a succeeding stage is significant in primary loading and reloading stage; (3) The amount of the creep deformation can be calculated accurately by an empirical formula.

Creep Property of Reticulate Red Clay under Stepped-Load Creep Tests

2012 ◽  
Vol 446-449 ◽  
pp. 1412-1416
Author(s):  
Jian Zhong Li ◽  
Yan Fu Cao ◽  
Ya Jun Qing
Keyword(s):  
Creep Property ◽  
Creep Tests ◽  
Red Clay ◽  
Reticulate Red Clay

Simulation on Triaxial Compression Creep Deformation of Reticulate Red Clay

2011 ◽  
Vol 261-263 ◽  
pp. 1414-1418 ◽  
Author(s):  
Jian Zhong Li ◽  
Xi Qing Tang ◽  
Lu Chao Yan
Keyword(s):  
Creep Deformation ◽  
Triaxial Compression ◽  
Lake Area ◽  
Compression Tests ◽  
Creep Tests ◽  
Red Clay ◽  
Creep Stress ◽  
Compression Creep ◽  
Reticulate Red Clay ◽  
Laboratory Test Results

Triaxial compression creep tests were performed on the undisturbed specimens of reticulate red clay from Dongting Lake area (China) under different confined stress. By analyzing the laboratory test results, following conclusions were drawn: (1) creep deformation occurred in all compression tests; (2) creep deformation increases as the increasing of the creep stress (compress stress) slightly; (3) the creep deformation occurred in the triaxial compression creep tests can be well simulated with Singh-Mitchell model.

An Empirical Constitutive Correlation for Regular Jugged Discontinuity of Rock Surfaces

2013 ◽  
Vol 5 (2) ◽  
pp. 258-268 ◽  
Author(s):  
Bin Yang ◽  
Sihao Mo ◽  
Ping Wu ◽  
Chaoqing He
Keyword(s):  
Deformation Property ◽  
Creep Property ◽  
Shear Stresses ◽  
Test Results ◽  
Creep Tests ◽  
Shear Creep ◽  
Burger Model ◽  
Structural Plane ◽  
Creep Velocity

AbstractThis paper presents a physical investigation and mathematical analysis on mechanical behavior of the regular jugged discontinuity. In particular, we focus on the creep property of structural plane with various slope angles under different normal stress through shear creep tests of structural plane under shear stresses. According to the test results, the shear creep property of structural plane was described and the creep velocity and long-term strength of the structural plane during shear creep were also investigated. An empirical formula is finally established to evaluate shear strength of discontinuity and a modified Burger model was proposed to represent the shear deformation property during creep.

The Empirical Formula Research and the Test for the Soft Clay Coupled Consolidation and Creep Character in Different Drainage Conditions

2011 ◽  
Vol 90-93 ◽  
pp. 1819-1823
Author(s):  
Bin Tang ◽  
Zhe Zeng ◽  
Yan Xia Gong
Keyword(s):  
Creep Deformation ◽  
Empirical Formula ◽  
Soft Clay ◽  
Soil Consolidation ◽  
Creep Tests ◽  
Stress Strain ◽  
Time Relationship ◽  
Deformation Amount ◽  
Deformation Speed ◽  
Consolidation Drainage

Abstract: Conducted a series of triaixl coupled consolidation and creep tests ,and researched the coupled consolidation and creep character for the typical soft clay in Wuhan region in different drainage conditions.The following conclusions are got from analysing the stress、strain and time relationship curves in different conditions:(1)The consolidation drainage condition is very important in the soil consolidation creep deformation.When the stress is low,the deformation amount in the consolidation undrained condition is much smaller than that in the consolidation drained condition;with the increasing of the stress,the viscoplasticity will appear,and the deformation speed in the undrained condition exceeded that in the drained condition;when the stress increases to some point,the deformation amount in the undrained condition will exceed that in the drained condition finally.(2)The consolidation creep deformation rule for the typical soft clay in Wuhan region in different drainage conditions can be expressed by empirical formula.

Behavior of Cemented Reticulate Red Clay

2012 ◽  
Vol 446-449 ◽  
pp. 1666-1669 ◽  
Author(s):  
Jian Zhong Li ◽  
Li Chun Zhuo ◽  
Xi Ni
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Cement Content ◽  
Axial Strain ◽  
Test Results ◽  
Compression Tests ◽  
Red Clay ◽  
Reticulate Red Clay ◽  
Strain Deviator ◽  
Relationship Of

Mechanical properties of cemented reticulate red clay were studied in present research. Test results show that: (1) shear strength of cemented reticulate red clay increase exponentially as the increasing of cement content; (2) shear strength of cemented reticulate red clay decrease polynomially as the increasing of water content; (3) mechanical properties of cemented reticulate red clay affected significantly by curing time and curing confined pressure. In order to study viscous properties of cemented reticulate red clay, cemented reticulate red clay specimens were compressed in triaxial chamber at different shear rate. Results of the compression tests show that it is obvious that the axial strain-deviator stress relationship of cemented reticulate red clay affects by the strain rate.

Study on the Creep Property by Small Beam Specimen With Fixed Constraint

2018 ◽  
Author(s):  
Zhou Guo-Yan ◽  
Qin Hong-Yu ◽  
Wang Jun-Qi ◽  
Tu Shan-Tung ◽  
Gong Jian-Guo
Keyword(s):  
Constitutive Equation ◽  
Creep Deformation ◽  
Creep Property ◽  
Von Mises Stress ◽  
Beam Specimen ◽  
Creep Tests ◽  
Efficient Operation ◽  
Uniaxial Creep ◽  
Material Creep ◽  
Von Mises

To guarantee the safe and highly efficient operation of the high temperature plants, evaluation of the material creep properties and deterioration are necessary. As for small-structure components, especially in service, the material is not sufficient to provide a standard specimen for creep tests. So, as one of the promising techniques, small specimen creep tests have been developed. Three-point bending specimen with fixed constraint (TPBSF) has been attracting scholars’ increasing interests due to its simple stress state and easily achievement of rupture data. However, the TPBSF is limited in many applications for its different constitutive equations and larger errors. In this study, on the basis of beam bending theory, the creep deformation formula of TPBSF was modified. Its feasibility and accuracy was verified by comparing with the creep test data of A7N01 aluminum alloy at 380 °C in literature. Further, based on this modified constitutive equation, finite element method was used to investigate the creep behavior of 0Cr18Ni9 at 600°C. The results show that the modified creep deformation constitutive equation correlates better with uniaxial creep. The corresponding creep parameters B and n of 0Cr18Ni9 at 600°C by TPBSF test are much closer to the experimental results by uniaxial specimen. Von Mises stress and normal stress distribute almost symmetrically along center line at the beginning. But they redistribute with increasing time and reach to a steady state with constant values.

scholarly journals Effect of Rejuvenation Heat Treatment on the Creep Property and Microstructural Evolution of a Ni-Base Superalloy

2020 ◽  
Vol 10 (3) ◽  
pp. 1187
Author(s):  
Linning Wang ◽  
Yuan Liu ◽  
Jingjing Liang
Keyword(s):  
Heat Treatment ◽  
Creep Strain ◽  
Microstructural Evolution ◽  
Creep Deformation ◽  
Creep Resistance ◽  
Creep Property ◽  
Creep Tests ◽  
Size And Morphology ◽  
Base Superalloy ◽  
Good Agreement

Interrupted creep tests were performed on a polycrystalline Ni-base superalloy, and rejuvenation heat treatment (RHT) was carried out to restore the creep resistance. During creep deformation, the microstructural evolution can be characterized as coarsening and rafting of γ′ precipitates, formation of dislocation networks in matrix channels, γ′ shearing by dislocations and carbides transformation from MC to M6C type. In the sample with low precrept strain, the dislocation networks can be effectively removed after RHT and the size and morphology of γ′ particles were similar to that just after heat treatment. However, the microstructure in the sample with higher creep strain after RHT cannot be fully restored to the original state in terms of dislocations and distribution of γ′ particles. The subsequent creep results exhibit that creep property is also relevant to the precrept strain, which exhibits a good agreement with microstructure observations. In addition, RHT cannot reverse the carbide transformation from MC to M6C type but enhances this process, which can be evident by the change of the area fraction of these two types of carbides. The effect of carbides transformation on the creep resistance of K465 alloy is not pronounced.

A Study on Estimation of Internal Pressure Creep Life Using Small Punch Creep (SPC) Tests for Boiler Pipes

2009 ◽  
Author(s):  
Toshimi Kobayashi ◽  
Toru Izaki ◽  
Junichi Kusumoto ◽  
Akihiro Kanaya
Keyword(s):  
Internal Pressure ◽  
Residual Life ◽  
Test Results ◽  
Creep Life ◽  
Creep Tests ◽  
Good Correspondence ◽  
Small Punch ◽  
Uniaxial Creep ◽  
Wide Range ◽  
The Relationship

The small punch creep (SPC) test is possible to predict residual creep life at a high accuracy. But, the results of SPC tests cannot be compared with uniaxial creep or internal pressure creep results directly. In this report, the relationship between SPC test results and uniaxial creep test results in ASME A335 P11 (1.25Cr-0.5Mo Steel) was studied. The obtained relationship between SPC load and equivalent uniaxial creep stress formed a simple linear equation under the wide range of test temperature and test period. Then, the SPC results can be compared with uniaxial results by converting SPC loads to the equivalent uniaxial creep stresses. The relationship between SPC test results and internal pressure creep tests results was also studied. The internal creep life of as-received P11 pipe was almost same as SPC result when the hoop stress was converted to the SPC load. The creep lives of internal pressure creep influenced materials also showed good correspondence with SPC results. Therefore SPC can estimate the residual life of internal pressure creep influenced materials.

Experimental Research on the Engineering Properties of Foam-Improved Red Clay Soil

2011 ◽  
Vol 261-263 ◽  
pp. 1831-1835
Author(s):  
Guo Gang Qiao ◽  
Da Jun Yuan ◽  
Bo Liu
Keyword(s):  
Experimental Research ◽  
Clay Soil ◽  
Soil Improvement ◽  
Engineering Properties ◽  
Screw Conveyor ◽  
Test Results ◽  
X Ray Diffraction ◽  
Shield Tunneling ◽  
Red Clay ◽  
Improvement Measures

Red clay soil is widely distributed in south China, the microstructure of red clay soil was studied applying scanning electron microscopy (SEM), and the X-ray diffraction analysis (XRD) test found that a large number of swelling inducing minerals, for example, montmorillonite, illite-montmorillonite or chlorite-smectite were contained in the red clay soil. Shield tunneling in this kind of stratum is prone to arising “cake” and “arch” phenomena and it prone to lead screw conveyor device unsmooth dumping, so soil improvement measures must be taken. Foam as the most advanced soil conditioner has been widely used in shield construction. Using self-developed foam agent, experimental research on foam conditioning red clay soil was carried out, test results show that foam can not only significantly reduce the soil shear strength, but also can greatly enhance the soil's compressibility and fluidity, which is significant for the smooth dumping and excavation face stability maintenance.

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