Secondary Development of a Nonlinear Creep Model Based on Fractional Derivative in FLAC3D

2018 ◽  
Author(s):  
Zhilei He ◽  
Bibo Dai
Keyword(s):  
Fractional Derivative ◽  
Creep Model ◽  
Secondary Development ◽  
Nonlinear Creep ◽  
Model Based

Secondary development and application of the NP-T creep model based on FLAC3D

2017 ◽  
Vol 10 (23) ◽  
Author(s):  
Luwang Chen ◽  
Shengjie Li ◽  
Kaixian Zhang ◽  
Yanxian Liu
Keyword(s):  
Creep Model ◽  
Secondary Development ◽  
Model Based

A nonlinear creep model based on the concept of slip

2011 ◽  
Vol 46 (6) ◽  
pp. 922-928
Author(s):  
A. M. Simonyan
Keyword(s):  
Creep Model ◽  
Nonlinear Creep ◽  
Model Based

scholarly journals A Nonlinear Creep Model of Rock Salt and Its Numerical Implement in FLAC3D

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Xinrong Liu ◽  
Xin Yang ◽  
Junbao Wang
Keyword(s):  
Numerical Simulation ◽  
Rock Salt ◽  
Creep Model ◽  
Secondary Development ◽  
Nonlinear Creep ◽  
Creep Properties ◽  
Long Term Stability ◽  
Creep Characteristics ◽  
Salt Creep

Creep characteristics are integral mechanical properties of rock salt and are related to both long-term stability and security of rock salt repository. Rock salt creep properties are studied in this paper through employing combined methods of theoretical analysis and numerical simulation with a nonlinear creep model and the secondary development in FLAC3Dsoftware. A numerical simulation of multistage loading creep was developed with the model and resulting calculations were found consequently to coincide with previously tested data.

Hunting Stability Analysis of a New High-Speed Railway Vehicle Model Moving on Curved Tracks

2007 ◽  
Author(s):  
Yung-Chang Cheng ◽  
Sen-Yung Lee
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Lateral Displacement ◽  
Creep Model ◽  
Railway Vehicle ◽  
Nonlinear Creep ◽  
Car Body ◽  
Suspension Parameters ◽  
Virtual Boundary ◽  
Hunting Stability

A new dynamic model of railway vehicle moving on curved tracks is proposed. In this new model, the motion of the car body is considered and the motion of the tuck frame is not restricted by a virtual boundary. Based on the heuristic nonlinear creep model, the nonlinear coupled differential equations of the motion of a fourteen degrees of freedom car system, considering the lateral displacement and the yaw angle of the each wheelset, the truck frame and the car body, moving on curved tracks are derived in completeness. To illustrate the accuracy of the analysis, the limiting cases are examined. In addition, the influences of the suspension parameters on the critical hunting speeds evaluated via the linear and the nonlinear creep models respectively are studied. Furthermore, the influences of the suspension parameters on the critical hunting speeds evaluated via the fourteen degrees of freedom car system and the six degrees of freedom truck system, which the motion of the tuck frame is restricted by a virtual boundary, are compared.

scholarly journals Nonlinear Viscoelastic–Plastic Creep Model Based on Coal Multistage Creep Tests and Experimental Validation

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3468 ◽  
Author(s):  
Junxiang Zhang ◽  
Bo Li ◽  
Conghui Zhang ◽  
Peng Li
Keyword(s):  
Creep Behavior ◽  
Physical Property ◽  
Creep Model ◽  
Creep Process ◽  
Creep Tests ◽  
Model Based ◽  
Nonlinear Viscoelastic ◽  
Improved Model ◽  
And Control ◽  
Plastic Creep

The development of fractures, which determine the complexity of coal creep characteristics, is the main physical property of coal relative to other rocks. This study conducted a series of multistage creep tests to investigate the creep behavior of coal under different stress levels. A negative elastic modulus and a non-Newtonian component were introduced into the classical Nishihara model based on the theoretical analysis of the experimental results to propose a nonlinear viscoelastic–plastic creep model for describing the non-decay creep behavior of coal. The validity of the model was verified by experimental data. The results show that this improved model can preferably exhibit decelerating, steady state, and accelerating creep behavior during the non-decay creep process. The fitting accuracy of the improved model was significantly higher than that of the classical Nishihara model. Given that acceleration creep is a critical stage in predicting the instability and failure of coal, its successful description using this improved model is crucial for the prevention and control of coal dynamic disasters.

scholarly journals New Maxwell Creep Model Based on Fractional and Elastic-Plastic Elements

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hao Tang ◽  
Dongpo Wang ◽  
Zhao Duan
Keyword(s):  
Rock Salt ◽  
Damage Mechanics ◽  
Rheological Behaviour ◽  
Creep Model ◽  
Creep Data ◽  
Creep Equation ◽  
New Model ◽  
Elastic Plastic ◽  
Simulation Performance ◽  
Model Based

Creep models are mainly used to describe the rheological behaviour of geotechnical materials. An important research focus for studying creep in geotechnical materials is the development of a model with few parameters and good simulation performance. Hence, in this study, by replacing the Newtonian dashpot and spring in the classical Maxwell model with fractional and elastic-plastic elements, a new Maxwell creep model based on fractional derivatives and continuum damage mechanics was developed. One- and three-dimensional (1D/3D) creep equations of the new Maxwell creep model were derived. The 1D creep equation of the new model was used to fit existing creep data of rock salt, and the 3D creep equation was used to fit the creep data of remolded loess. The model curves matched the creep data very well, showing considerably higher accuracy than other models. Furthermore, a sensitivity study was carried out, showing the effects of the fractional derivative order β and exponent α on the creep strain of rock salt. This new model is simple with few parameters and can effectively simulate the complete creep behaviour of geotechnical materials.

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