THE CREEP OF ICE IN BENDING

1963 ◽  
Vol 41 (1) ◽  
pp. 167-177 ◽  
Author(s):  
A. S. Krausz
Keyword(s):  
Strain Rate ◽  
Creep Behavior ◽  
Transient Creep ◽  
Neutral Axis ◽  
Maximum Strain ◽  
Maximum Value ◽  
Reversed Loading ◽  
Permanent Property

Observations were made on the creep behavior of columnar ice beams of different thicknesses subjected to repeated and reversed loading. More than half of the beams tested showed unusual creep behavior. During transient creep the strain rate increased to a maximum value and decreased only thereafter. It was established that this behavior was not a permanent property of ice. On reloading, the same beams exhibited normal creep behavior. For the conditions of the experiments, the deflection was very sensitive to the thickness of the beams. It was found that the neutral axis was located at the center of the beam when the maximum strain was less than 1%.

Transient Creep Behavior of γ-TiAl Polycrystals

1996 ◽  
Vol 460 ◽  
Author(s):  
B. Viguier ◽  
J. Bonneville ◽  
P. Spätig ◽  
J. L. Martin
Keyword(s):  
Plastic Strain ◽  
Strain Rate ◽  
Strain Hardening ◽  
Creep Behavior ◽  
Room Temperature ◽  
Constant Strain Rate ◽  
Transient Creep ◽  
Load Relaxation ◽  
Hardening Coefficient ◽  
Good Agreement

ABSTRACTTwo types of transient creep experiments performed along stress-strain curves are described and successfully applied to γ TiAl polycrystals at room temperature. They allow to determine activation volumes in good agreement with those measured through successive load relaxation tests. In addition, the combination of the latter method and the present ones provides relevant values of the plastic strain hardening coefficient. This latter parameter is found to exhibit similar values in transient as well as during constant strain rate tests.

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.

Transient creep behavior of a novel tempered martensite ferritic steel G115

2018 ◽  
Vol 716 ◽  
pp. 284-295 ◽  
Author(s):  
Bo Xiao ◽  
Lianyong Xu ◽  
Lei Zhao ◽  
Hongyang Jing ◽  
Yongdian Han ◽  
...  
Keyword(s):  
Creep Behavior ◽  
Ferritic Steel ◽  
Transient Creep ◽  
Tempered Martensite

Superplastic Behavior of B- and Gd-Containing β-Solidifying TiAl Based Alloy

2018 ◽  
Vol 385 ◽  
pp. 131-136
Author(s):  
Vitaliy Sokolovsky ◽  
Nikita Stepanov ◽  
Sergey Zherebtsov ◽  
Nadezhda Nochovnaya ◽  
Pavel Panin ◽  
...  
Keyword(s):  
Strain Rate ◽  
Mechanical Behavior ◽  
Strain Rate Sensitivity ◽  
Phase Field ◽  
Rate Sensitivity ◽  
Maximum Strain ◽  
Superplastic Behavior ◽  
Β Phase ◽  
Refined Microstructure ◽  
Phase Fields

Mechanical behavior and microstructure evolution of the cast Ti-43.2Al-1.9V-1.1Nb-1.0Zr-0.2Gd-0.2B alloy were studied at temperatures from 1100 to 1250°С and strain rates in the range 0.001-1 s-1. Following phase fields (α2+γ), (α+γ), (α) and (α+β) during heating of alloy were revealed. Microstructure analysis after deformation and mechanical behavior allowed defining main processes of structure formation. Two temperature-strain rate conditions with pronounced superplastic behaviour were found: the first one corresponded to the (α2+γ)-phase field (1100°C), where the microstructure had mainly a lamellar morphology, and the second was associated with the (α+β)-phase field (1250°C), in which the α-phase dominated. At T=1100°C and έ=0.05 s-1the maximum strain rate sensitivitymwas of 0.40. At T=1250°C and έ=0.5 s-1the maximum strain rate sensitivitymwas of 0.59. In the (α2+γ)-phase field, superplastic behavior was associated with the transformation of the lamellar structure into globular one. In the (α+β)-phase field, it was due to the formation of a homogeneous refined microstructure during dynamic recrystallization. The relationship between coefficient m value and microstructure formed was discussed.

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.

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