scholarly journals Study on the Creep Behaviors of Interactive Marine-Terrestrial Deposit Soils

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Zhen Yan ◽  
Gang Li ◽  
Jinli Zhang ◽  
Rui Zhang
Keyword(s):  
Creep Behavior ◽  
Axial Strain ◽  
Nonlinear Creep ◽  
Creep Tests ◽  
Creep Equation ◽  
One Dimensional ◽  
Consolidation Pressure ◽  
Deviator Stress ◽  
Consolidation Coefficient ◽  
Triaxial Creep

The interactive marine-terrestrial (IMT) deposit soils were formed in the complex depositional environment; their mechanical properties are different from the other deposits. The creep behaviors of Dalian clayey soils were studied according to one-dimensional creep tests and drained triaxial creep tests. Based on the creep test results, the empirical model was established to describe the one-dimensional creep behavior and triaxial creep behavior, respectively. The results showed that Dalian deposits have typical nonlinear creep behavior. With the increasing of consolidation pressure, the strain is increased, the stability time is extended, and the demarcation point between primary and secondary consolidation is more obvious. The deposits belong to medium to high secondary compressibility soil, and the secondary consolidation coefficient is decreased with the increasing of consolidation time and increased with consolidation pressure increasing. The ratio between secondary consolidation coefficient and compression index at different depths changes from 0.033 to 0.058, which conform to Mesri conclusion. Under low deviator stress, the creep processes showed the characteristic of attenuation creep and shear contraction. However, it showed the characteristic of acceleration creep, shear contraction, and shear dilatancy under damage deviator stress. The axial strain rate decreased with the increasing of creep time and increased with the deviator stress increasing, while the deviator stress has little effect on the m values. The tests results agree well with the calculation results, which showed that the creep equation is suitable for describing the creep behaviors of Dalian interactive marine-terrestrial deposits.

scholarly journals An Improved Nishihara Model for Frozen Loess considering the Influence of Temperature

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xin Li ◽  
Enlong Liu ◽  
Bingtang Song ◽  
Xingyan Liu
Keyword(s):  
Creep Behavior ◽  
Microscopic Analysis ◽  
Confining Pressure ◽  
Deviatoric Stress ◽  
Frozen Soil ◽  
Experimental Results ◽  
Creep Process ◽  
Model Parameters ◽  
Creep Tests ◽  
Deviator Stress

A series of triaxial creep tests under the constant confining pressure are performed on frozen loess specimens, and the creep behavior of the frozen loess with respect to variations in both temperature and deviator stress is examined. Experimental results illustrate that the frozen loess specimens present the attenuation creep at the lower deviatoric stress, whereas the nonattenuation creep under the higher deviatoric stress level, and with a drop in the temperature, the deviator stress value which the exhibition of nonattenuation creep needs will increase under the constant confining pressure condition. According to the microscopic analysis on deformation characteristics in the creep process of frozen soil, both temperature and external stress will cause the hardening and weakening effects, affecting the creep properties of frozen loess. By introducing the hardening variable and damage variable to consider the hardening and weakening effects of the frozen loess, an improved Nishihara model is proposed. The correlations between model parameters and the temperature as well as deviator stress are determined. The comparisons between model predictions and experimental results show that the improved creep constitutive model proposed here can not only describe the whole creep process well, but also reveal the influences of the temperature and deviator stress on the creep behavior of frozen loess, which demonstrate its accuracy and usefulness.

scholarly journals Test Study on the Creep Behaviors of Tianjin Clays

2019 ◽  
Vol 136 ◽  
pp. 07029
Author(s):  
Gang Li ◽  
Zhen Yan ◽  
Jinli Zhang ◽  
Jia Liu ◽  
Yu Xi
Keyword(s):  
Strain Rate ◽  
Axial Strain ◽  
Deviatoric Stress ◽  
Test Results ◽  
Creep Tests ◽  
Creep Properties ◽  
Test Study ◽  
Undisturbed Samples ◽  
Calculation Results ◽  
Triaxial Creep

The drained triaxial creep tests were carriedout to investigate the relationshipsbetween axial strain and time, axial strain and deviatoricstress, and axial strain rate and time for the undisturbed samples of muddy clay and clay in Tianjin.Based on the creep test results, the Singh-Mitchell modelwas used for creep calculation. The results showed that the muddyclay and clay exhibited typical non-linear creep properties. The axial strain increasedwith time and then gradually tendedto be stable.The strain rate increasedasthe deviatoric stress increased, and the muddy clay and clay showedthe characteristics of attenuation creep under deviatoricstresses. The axial strain of muddy clay wassignificantly larger than that of clay, and reachedthestable state within 3000 minutes.Under low deviatoricstress, the slope of the isochronal curve was smaller; while under high deviatoric stress, the slope of the isochronal curve waslarger.The test results were in good agreement with the calculation results, which indicated that the Singh-Mitchell model wassuitable for describing the creep behaviorsof the undisturbed claysin Tianjin.

Creep Behavior of Shale: Nanoindentation vs. Triaxial Creep Tests

2020 ◽  
Author(s):  
Kouqi Liu ◽  
Fatemeh S. Rassouli ◽  
Bo Liu ◽  
Mehdi Ostadhassan
Keyword(s):  
Creep Behavior ◽  
Creep Tests ◽  
Triaxial Creep ◽  
Triaxial Creep Tests

scholarly journals Determination of the creep behavior of potato tubers during storage period by means of uniaxial and triaxial creep tests

2020 ◽  
Vol 8 (4) ◽  
pp. 1857-1863
Author(s):  
Gholamhossein Shahgholi ◽  
Meysam Latifi ◽  
Behrooz Imani ◽  
Niusha Farrokhi
Keyword(s):  
Creep Behavior ◽  
Storage Period ◽  
Potato Tubers ◽  
Creep Tests ◽  
Triaxial Creep ◽  
Triaxial Creep Tests

Creep Behavior of Building Silicone Sealant under Long-Term External Loading and its Time-Stress Equivalence

2014 ◽  
Vol 633 ◽  
pp. 451-454
Author(s):  
Xiao Gen Liu ◽  
Yi Wang Bao ◽  
Xiu Fang Wang
Keyword(s):  
Creep Curve ◽  
Creep Behavior ◽  
External Loading ◽  
Nonlinear Creep ◽  
Creep Tests ◽  
Time Stress ◽  
Silicone Sealant ◽  
Term Creep ◽  
Term Performance

The main mechanics behavior character of building silicone sealant is its time dependence£¬which lies in the existence of the interior timepiece or the characteristic time. The creep behaviors were fundamental to evaluating the long-term performance of the building silicone sealant under long-term external loading. A series of creep tests of building silicone sealant were conducted in the laboratory under different combinations of external loads, the characteristics of the creep curve were obtained. In this work, the creep behaviors of building silicone sealant were also investigated under various temperatures at invariable stress. The test measurements show that the creep behavior of building silicone sealant are nonlinear, Nonlinear creep behavior is analyzed by means of the equivalence principle of time-stress, the main creep curve under reference stress was obtained by fitting with the viscoelastic rheological model. So the long-term creep behavior of the building silicone sealant under lower stress can be predicted by short-term creep behavior under higher stress.

scholarly journals Creep Behaviors of Methane Hydrate-Bearing Frozen Sediments

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 251 ◽  
Author(s):  
Yanghui Li ◽  
Peng Wu ◽  
Xiang Sun ◽  
Weiguo Liu ◽  
Yongchen Song ◽  
...  
Keyword(s):  
Strain Rate ◽  
Methane Hydrate ◽  
Axial Strain ◽  
Confining Pressure ◽  
Creep Tests ◽  
Creep Stage ◽  
Long Term Stability ◽  
Deviator Stress ◽  
Strain And Strain Rate

Creep behaviors of methane hydrate-bearing frozen specimens are important to predict the long-term stability of the hydrate-bearing layers in Arctic and permafrost regions. In this study, a series of creep tests were conducted, and the results indicated that: (1) higher deviator stress (external load) results in larger initial strain, axial strain, and strain rate at a specific elapsed time. Under low deviator stress levels, the axial strain is not large and does not get into the tertiary creep stage in comparison with that under high deviator stress, which can be even up to 35% and can cause failure; (2) both axial strain and strain rate of methane hydrate-bearing frozen specimens increase with the enhancement of deviator stress, the decrease of confining pressure, and the decrease of temperature; (3) the specimens will be damaged rather than in stable creep stage during creeping when the deviator stress exceeds the quasi-static strength of the specimens.

Creep Behavior of a TWARON®/Natural Rubber Composite

2010 ◽  
Author(s):  
N. V. David ◽  
X.-L. Gao ◽  
J. Q. Zheng
Keyword(s):  
Natural Rubber ◽  
Creep Behavior ◽  
Rheological Model ◽  
Axial Strain ◽  
Time Spectrum ◽  
Secondary Creep ◽  
Creep Tests ◽  
Creep Response ◽  
Rubber Composite ◽  
Different Levels

The creep behavior of a Twaron CT709® fabric/natural rubber composite under a uniaxial constant stress is studied using three viscoelasticity models with different levels of complexity and a newly developed para-rheological model. The three models employed are a one-term generalized Maxwell (GMn = 1) model (consisting of one Maxwell element and an additional spring in parallel), a two-term generalized Maxwell (GMn = 2) model (including two parallel Maxwell elements and an additional spring in parallel), and a four-parameter Burgers model. The values of the parameters involved in each model are extracted from the experimental data obtained in this study. The creep tests reveal that the axial strain starts to increase exponentially during the primary stage and then continues to equilibrate linearly with time. The results show that the initial creep response of the composite is predicted fairly well by the GMn = 2 model, while the secondary creep is more accurately described by the GMn = 1 model. An implicit solution, together with a characteristic retardation time spectrum, obtained using the para-rheological model is found to provide more accurate predictions of the composite creep response than the three viscoelasticity models at both the primary and secondary stages.

Statistical analysis of creep behavior in thermoset and thermoplastic composites reinforced with carbon and glass fibers

2020 ◽  
pp. 030932472097663
Author(s):  
Francisco Maciel Monticeli ◽  
Ana Karoline dos Reis ◽  
Roberta Motta Neves ◽  
Luis Felipe de Paula Santos ◽  
Edson Cocchieri Botelho ◽  
...  
Keyword(s):  
Creep Behavior ◽  
Glass Fibers ◽  
Laminated Composite ◽  
Analytical Models ◽  
Thermoplastic Composites ◽  
Temperature Dependent ◽  
Creep Tests ◽  
Thermoset Composites ◽  
Strain Behavior ◽  
Sensitivity Range

The thermoplastic and thermoset laminates reinforced with different fibers generate variations in the laminated composite mechanical behavior. This work aims to analyze thermoplastic and thermoset composites creep behavior with a reduced number of experiments, applying curve-fitting analytical models (Weibull and Findley) and statistical approach (ANOVA, F-test, and SRM) in order to describe creep behavior. Creep tests were carried out using a design of experiments to define parameter levels, aiming to reduce the number of the experiments, keeping reliability relevance. The temperature shows a stronger influence of creep deformation compared with the use of distinct materials. Thermoplastic matrices seem to be more sensitive to deformation, decreasing the reinforcement contribution. On the other hand, the creep resistance of the thermoset matrix conducts a significant contribution of strain behavior for the reinforcement used. The Findley model showed a temperature-dependent response. While, the Weibull-based model exhibits temperature and material-dependence, ensuring a greater sensitivity range of the parameters applied, an essential factor for a more realistic method description.

An Experimental Study on the Effect of Prior Plastic Straining on Creep Behavior of 304 Stainless Steel

1993 ◽  
Vol 115 (2) ◽  
pp. 200-203 ◽  
Author(s):  
Z. Xia ◽  
F. Ellyin
Keyword(s):  
Stainless Steel ◽  
Plastic Strain ◽  
Strain Rate ◽  
Creep Behavior ◽  
Test Procedure ◽  
Constant Strain Rate ◽  
304 Stainless Steel ◽  
Creep Model ◽  
Plastic Strain Rate ◽  
Creep Tests

Constant strain-rate plastic straining followed by creep tests were conducted to investigate the effect of prior plastic straining on the subsequent creep behavior of 304 stainless steel at room temperature. The effects of plastic strain and plastic strain-rate were delineated by a specially designed test procedure, and it is found that both factors have a strong influence on the subsequent creep deformation. A creep model combining the two factors is then developed. The predictions of the model are in good agreement with the test results.

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