Time-Dependent Viscoplastic Model for Dislocation Generation During the Cooling Process in the Silicon Ingot

2016 ◽  
pp. 27-33
Author(s):  
Maohua Lin ◽  
Qingde Chen ◽  
C. T. Tsai
Keyword(s):  
Time Dependent ◽  
Cooling Process ◽  
Dislocation Generation ◽  
Viscoplastic Model ◽  
Silicon Ingot

Constitutive Modeling for Uniaxial Time-Dependent Ratcheting of SS304 Stainless Steel

2007 ◽  
Vol 340-341 ◽  
pp. 817-822 ◽  
Author(s):  
Guo Zheng Kang ◽  
Qian Hua Kan ◽  
Juan Zhang ◽  
Yu Jie Liu
Keyword(s):  
Stainless Steel ◽  
Room Temperature ◽  
Kinematic Hardening ◽  
Constitutive Models ◽  
Experimental Results ◽  
Time Dependent ◽  
Dominant Factor ◽  
Superposition Model ◽  
Viscoplastic Model ◽  
Reasonable Description

Based on the experimental results of uniaxial time-dependent ratcheting behavior of SS304 stainless steel at room temperature and 973K, three kinds of time-dependent constitutive models were employed to describe such time-dependent ratcheting by using the Ohno-Abdel-Karim kinematic hardening rule, i.e., a unified viscoplastic model, a creep-plasticity superposition model and a creep-viscoplasticity superposition model. The capabilities of such models to describe the time-dependent ratcheting were discussed by comparing with the corresponding experimental results. It is shown that the unified viscoplastic model cannot provide reasonable simulation to the time-dependent ratcheting, especially to those with certain peak/valley stress hold and at 973K; the proposed creep-plasticity superposition model is reasonable when the creep is a dominant factor of the deformation, however, it cannot provide a reasonable description when the creep is weak; the creep-viscoplastic superposition model is reasonable not only at room temperature but also at high temperature.

Creep and Dilatancy Behavior of Rock Salt around Underground Caverns

2012 ◽  
Vol 629 ◽  
pp. 418-422
Author(s):  
S. Nazary Moghadam ◽  
H. Mirzabozorg ◽  
A. Noorzad ◽  
K. Nazokkar
Keyword(s):  
Finite Element ◽  
Rock Salt ◽  
Time Dependent ◽  
Finite Element Analyses ◽  
Volume Changes ◽  
Viscoplastic Model ◽  
Dependent Behavior ◽  
Underground Caverns ◽  
Finite Element Procedure ◽  
Stress And Deformation

In the present paper, the time-dependent behavior of a salt cavern was analyzed using finite element method. A viscoplastic model considering inelastic volume changes was utilized to describe the time-dependent mechanical behavior of rock salt. The model was then implemented in a finite element procedure to analyze the stress and deformation of rock salt around an underground cavern using an axisymmetric representation. Finally, finite element analyses results were compared with those obtained by a viscoplastic model neglecting inelastic volume changes.

Observed and calculated pore pressures and deformations induced by an earth balance shield

1993 ◽  
Vol 30 (3) ◽  
pp. 476-490 ◽  
Author(s):  
X. Yi ◽  
R. Kerry Rowe ◽  
K.M. Lee
Keyword(s):  
Finite Element ◽  
Numerical Technique ◽  
Field Measurements ◽  
Time Dependent ◽  
Creep Tests ◽  
Viscoplastic Model ◽  
Pore Pressures ◽  
Triaxial Creep ◽  
Consolidation Analysis ◽  
Triaxial Creep Tests

The observed pore pressures and deformations induced by an earth balance shield used to construct the Furongjiang sewer tunnel in soft saturated ground in Shanghai, China, are briefly described. A numerical technique for predicting these pore pressures and deformations is outlined. This approach adopts a coupled viscoplastic-consolidation analysis to describe the time-dependent deformations and strain-hardening behaviour of the soil using parameters obtained from triaxial creep tests. A comparison is then made between numerical results and the results of field measurements, and it is shown that there is encouraging agreement between the calculated and observed response. Key words : tunnelling, finite element, settlements, viscoplastic model, consolidation, field measurement.

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