Shear creep deformation in polysynthetically twinned (PST) Ti–47Al–2Nb–2Cr with 〈110〉 and 〈112〉 orientations

1997 ◽  
Vol 239-240 ◽  
pp. 450-456 ◽  
Author(s):  
Dong Yi Seo ◽  
Chih Huei Wu ◽  
Thomas R. Bieler
Keyword(s):  
Creep Deformation ◽  
Shear Creep

scholarly journals Shear Creep Simulation of Structural Plane of Rock Mass Based on Discontinuous Deformation Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Guoxin Zhang ◽  
Zhengqi Lei ◽  
Heng Cheng
Keyword(s):  
Rock Mass ◽  
Numerical Simulations ◽  
Creep Deformation ◽  
Discontinuous Deformation Analysis ◽  
Deformation Analysis ◽  
Shear Creep ◽  
Time Step ◽  
Structural Plane ◽  
Discontinuous Deformation ◽  
Dda Method

Numerical simulations of the creep characteristics of the structural plane of rock mass are very useful. However, most existing simulation methods are based on continuum mechanics and hence are unsuitable in the case of large displacements and deformations. The discontinuous deformation analysis method proposed by Genhua is a discrete one and has a significant advantage when simulating the contacting problem of blocks. In this study, we combined the viscoelastic rheological model of Burgers with the discontinuous deformation analysis (DDA) method. We also derived the recurrence formula for the creep deformation increment with the time step during numerical simulations. Based on the minimum potential energy principle, the general equilibrium equation was derived, and the shear creep deformation in the structural plane was considered. A numerical program was also developed and its effectiveness was confirmed based on the curves obtained by the creep test of the structural plane of a rock mass under different stress levels. Finally, the program was used to analyze the mechanism responsible for the creep features of the structural plane in the case of the toppling deformation of the rock slope. The results showed that the extended DDA method is an effective one.

scholarly journals Creep in Shear of Experimental Solder Joints

1990 ◽  
Vol 112 (2) ◽  
pp. 87-93 ◽  
Author(s):  
D. Tribula ◽  
J. W. Morris
Keyword(s):  
Thermal Fatigue ◽  
Creep Deformation ◽  
Solder Joints ◽  
Shear Strain Rate ◽  
Creep Failure ◽  
Shear Creep ◽  
Binary Eutectic ◽  
Element Addition ◽  
Fatigue Failures ◽  
Operative Temperatures

Thermal fatigue failures of solder joints in electronic devices are a great concern in the electronics industry. Since the fatigue load is often in shear the details of thermal fatigue failure in shear are of particular interest. Recent work indicates that similar failure mechanisms operate in both thermal fatigue in shear and unidirectional creep in shear. Additionally, since the operative temperatures during thermal fatigue represent high solder homologous temperatures, creep deformation is certainly involved. These factors and the relative case of conducting creep experiments encourage the study of solder joints under shear creep conditions. This work presents steady state shear creep rate vs. shear stress data for several solder compositions, including the binary eutectic alloy and Pb-Sn alloyed with small amounts of Bi, Cd, In, and Sb, in a joint configuration. These data indicate that conventional creep mechanisms operate in the temperature and shear strain rate ranges studies. Extensive microstructural information is also reported. The microstructural evolution under creep conditions indicates that the instability of the as-cast binary Pb-Sn eutectic microstructure initiates creep failure. Changes of the as-solidified microstructure with the third element addition are reported as are the microstructural responses of each of these alloys to creep deformation. The efficacy of postponing the microstructural instability with the addition of small amounts of ternary elements is discussed.

Analysis of local microstructure after shear creep deformation of a fine-grained duplex γ-TiAl alloy

2010 ◽  
Vol 58 (19) ◽  
pp. 6431-6443 ◽  
Author(s):  
D. Peter ◽  
G.B. Viswanathan ◽  
A. Dlouhy ◽  
G. Eggeler
Keyword(s):  
Creep Deformation ◽  
Tial Alloy ◽  
Shear Creep ◽  
Fine Grained

scholarly journals The Strain Rate Sensitivity and Creep Behavior for the Tripler Plane of Potassium Dihydrogen Phosphate Crystal by Nanoindentation

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 369
Author(s):  
Jianhui Mao ◽  
Wenjun Liu ◽  
Dongfang Li ◽  
Chenkai Zhang ◽  
Yi Ma
Keyword(s):  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Creep Deformation ◽  
Potassium Dihydrogen Phosphate ◽  
Rate Sensitivity ◽  
Dislocation Nucleation ◽  
Machining Process ◽  
Dihydrogen Phosphate ◽  
Potassium Dihydrogen ◽  
Kdp Crystals

As an excellent multifunctional single crystal, potassium dihydrogen phosphate (KDP) is a well-known, difficult-to-process material for its soft-brittle and deliquescent nature. The surface mechanical properties are critical to the machining process; however, the characteristics of deformation behavior for KDP crystals have not been well studied. In this work, the strain rate effect on hardness was investigated on the mechanically polished tripler plane of a KDP crystal relying on nanoindentation technology. By increasing the strain rate from 0.001 to 0.1 s−1, hardness increased from 1.67 to 2.07 GPa. Hence, the strain rate sensitivity was determined as 0.053, and the activation volume of dislocation nucleation was 169 Å3. Based on the constant load-holding method, creep deformation was studied at various holding depths at room temperature. Under the spherical tip, creep deformation could be greatly enhanced with increasing holding depth, which was mainly due to the enlarged holding strain. Under the self-similar Berkovich indenter, creep strain could be reduced at a deeper location. Such an indentation size effect on creep deformation was firstly reported for KDP crystals. The strain rate sensitivity of the steady-state creep flow was estimated, and the creep mechanism was qualitatively discussed.

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