The Effects of Temperature, Stress and Salinity on the Creep of Frozen Saline Soil

1984 ◽  
Vol 106 (3) ◽  
pp. 344-348 ◽  
Author(s):  
M. S. Nixon ◽  
G. M. Pharr
Keyword(s):  
Temperature Stress ◽  
Creep Behavior ◽  
Saline Soil ◽  
Constant Load ◽  
Unconfined Compression ◽  
Strong Function ◽  
Bay Area ◽  
Effects Of Temperature ◽  
Ice Content ◽  
Prudhoe Bay

Gravel of the Prudhoe Bay area of Alaska used in the construction of artificial islands has been examined in constant load creep experiments to determine the effects of temperature, stress, and salinity on its creep behavior in unconfined compression. Over the range of conditions studied, it is found that the creep behavior is strongly dependent on each of these variables. In addition, the ice content of the specimen, itself a strong function of temperature and salinity, is found to be an important strength-determining parameter.

Modeling and Optimization of Creep Behavior of Ni-Based Superalloys GTD-111 and IN-738LC Using Central Composite Design

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
O. Ganji ◽  
A. R. Shadman ◽  
S. A. Sajjadi
Keyword(s):  
Creep Rate ◽  
Central Composite Design ◽  
Temperature Stress ◽  
Creep Behavior ◽  
Numerical Results ◽  
Rupture Time ◽  
Modeling And Optimization ◽  
Effects Of Temperature ◽  
Main Effects ◽  
Central Composite

In this study, the effects of temperature, stress, and type of materials and their interactions on the creep rate and rupture time were investigated by using central composite design (CCD). An experimental plan for CCD with two numerical factors, one categorical factor, and two levels was used to optimize the required number of experiments. Temperatures of 800 and 900 °C and stresses of 250 and 450 MPa were selected as factors for GTD-111 and IN-738LC superalloys, respectively. Experimental and numerical results showed that the main effects of factors and their interactions are significant on the creep rate and rupture time. Among all factors, the effects of temperature and stress dominated other factors. Moreover, it was indicated that the combination between temperature and stress is much more effective on creep rate response than on rupture time. The high creep rate and the low rupture time values were obtained at the highest stress and temperature for IN-738LC. With the same experimental condition, creep rate values were the most and rupture time values were the least for IN-738LC in comparison with GTD-111.

Creep in Ordered Nickel Base Alloys

1984 ◽  
Vol 39 ◽  
Author(s):  
P. R. Strutt ◽  
B. H. Kear
Keyword(s):  
Creep Behavior ◽  
Creep Deformation ◽  
Crystallographic Orientation ◽  
Deformation Behavior ◽  
Strong Influence ◽  
Deformation Mode ◽  
Two Phase ◽  
Effects Of Temperature ◽  
Nickel Base ◽  
Relative Creep

ABSTRACTThis paper examines the fundamentals of deformation behavior in ordered y′ (Ni3Al), β (NiAl) and β′ (Ni2AITi) phases, and specific two phase y/y′ and B/B′ alloys. The relative creep strengths of these ordered nickel-base alloys are discussed. Differences in creep behavior are explained in terms of the effects of temperature, crystallographic orientation and alloying on creep deformation mode. In particular, it is shown that trace additions of boron and carbon to y/y′ alloys, or deviations from stoichiometry in β′ -type alloys can exert a strong influence on creep behavior.

scholarly journals Nanoindentation Studies of Plasticity and Dislocation Creep in Halite

Geosciences ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 79 ◽  
Author(s):  
Christopher Thom ◽  
David Goldsby
Keyword(s):  
Strain Rate ◽  
Stress Exponent ◽  
Creep Behavior ◽  
Constant Load ◽  
Dislocation Creep ◽  
Indentation Creep ◽  
Creep Tests ◽  
Creep Flow ◽  
A Value ◽  
Flow Laws

Previous deformation experiments on halite have collectively explored different creep mechanisms, including dislocation creep and pressure solution. Here, we use an alternative to conventional uniaxial or triaxial deformation experiments—nanoindentation tests—to measure the hardness and creep behavior of single crystals of halite at room temperature. The hardness tests reveal two key phenomena: (1) strain rate-dependent hardness characterized by a value of the stress exponent of ~25, and (2) an indentation size effect, whereby hardness decreases with increasing size of the indents. Indentation creep tests were performed for hold times ranging from 3600 to 106 s, with a constant load of 100 mN. For hold times longer than 3 × 104 s, a transition from plasticity to power-law creep is observed as the stress decreases during the hold, with the latter characterized by a value of the stress exponent of 4.87 ± 0.91. An existing theoretical analysis allows us to directly compare our indentation creep data with dislocation creep flow laws for halite derived from triaxial experiments on polycrystalline samples. Using this analysis, we show an excellent agreement between our data and the flow laws, with the strain rate at a given stress varying by less than 5% for a commonly used flow law. Our results underscore the utility of using nanoindentation as an alternative to more conventional methods to measure the creep behavior of geological materials.

A Study of Creep Behavior of TSV-Cu Based on Nanoindentaion Creep Test

2016 ◽  
Vol 32 (6) ◽  
pp. 717-724 ◽  
Author(s):  
W. Wu ◽  
F. Qin ◽  
T. An ◽  
P. Chen
Keyword(s):  
Strain Rate ◽  
Creep Behavior ◽  
Rate Sensitivity ◽  
Constant Load ◽  
Mean Value ◽  
Creep Tests ◽  
Rate Method ◽  
The Mean ◽  
Previous Loading ◽  
Indentation Strain

AbstractThrough-Silicon-Via (TSV) is considered to be the most potential solution for 3D electronic packaging, and the mechanical properties of TSV-Cu are critical for TSV reliability improving. In this paper, to make deeply understand the creep behavior of TSV-Cu, nanoindentation creep tests were conducted to obtain its creep parameters. At first, the TSV specimens were fabricated by means of a typical TSV manufacturing process. Then a combination programmable procedure of the constant indentation strain rate method and the constant load method was employed to study the creep behavior of TSV-Cu. To understand the influence of the previous loading schemes, including the different values of the indentation strain and the maximum depths, the nanoindentation creep tests under different loading conditions were conducted. The values of creep strain rate sensitivity m were derived from the corresponding displacement-holding time curves, and the mean value of m finally determined was 0.0149. The value of m is considered no obvious correlation with the different indentation strain rates and the maximum depths by this method. Furthermore, the mechanism for the room temperature creep was also discussed, and the grain boundaries might play an significant role in this creep behavior.

Effects of temperature stress and ultraviolet radiation stress on antioxidant systems ofLocusta migratoria tibetensisChen

2012 ◽  
Vol 32 (10) ◽  
pp. 3189-3197 ◽  
Author(s):  
李庆 LI Qing ◽  
吴蕾 WU Lei ◽  
杨刚 YANG Gang ◽  
匡健康 KUAN Jiankang ◽  
封传红 FENG Chuanhong ◽  
...  
Keyword(s):  
Ultraviolet Radiation ◽  
Temperature Stress ◽  
Antioxidant Systems ◽  
Radiation Stress ◽  
Effects Of Temperature

Shifts in Fox Den Occupancy in the Greater Prudhoe Bay Area, Alaska

ARCTIC ◽  
2014 ◽  
Vol 67 (2) ◽  
pp. 196 ◽  
Author(s):  
Alice A. Stickney ◽  
Tim Obritschkewitsch ◽  
Robert M. Burgess
Keyword(s):  
Bay Area ◽  
Prudhoe Bay

Creep Model Based on Theta Projection and Omega Method for Predicting the Creep Behavior of Alloy

2007 ◽  
Vol 353-358 ◽  
pp. 533-536
Author(s):  
Bong Min Song ◽  
Jong Yup Kim ◽  
Joon Hyun Lee
Keyword(s):  
Creep Behavior ◽  
Constant Load ◽  
Control Mode ◽  
Creep Model ◽  
Test Results ◽  
Creep Data ◽  
Creep Tests ◽  
Omega Method ◽  
Improved Model ◽  
Term Creep

Creep testing of Alloy 718 has been carried out at various loads in the temperature range near 650°C in constant load control mode in order to understand how to predict the creep behavior including tertiary creep. The test results have been used for evaluating the existed models, such as Theta projection and Omega method that have been widely used for predicting long term creep strain and rupture time. After determining variables and material parameters of each method with the test results, estimated creep data from each model have been compared with the each measured creep data from the creep tests. The root cause of the discrepancy between estimated and measured data has been analyzed in order to improve the existed methods. The reliability of the improved model has been evaluated in relation to creep data.

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