Nonlinear creep model and parameter identification of mudstone based on a modified fractional viscous body

2019 ◽  
Vol 78 (20) ◽  
Author(s):  
Yang Song ◽  
Heping Wang ◽  
Yongtao Chang ◽  
Yongqi Li
Keyword(s):  
Parameter Identification ◽  
Creep Model ◽  
Nonlinear Creep

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 Creep Model of Deep Gangue Backfilling Material and Time-Dependent Characteristics of Roof Deformation in Backfilling Mining

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Peng Huang ◽  
Jixiong Zhang ◽  
Qi Zhang ◽  
Ntigurirwa Jean Damascene ◽  
Yuming Guo
Keyword(s):  
Large Scale ◽  
High Stress ◽  
Viscoelastic Model ◽  
Creep Model ◽  
Mine Pressure ◽  
Nonlinear Creep ◽  
Viscoelastic Foundation ◽  
The Impact ◽  
Roof Deformation

With the gradual increase in mining depth of coal resource exploitation, deep backfilling mining has effectively solved the impact of strong deep mine pressure and strong mining disturbances. However, after deep backfilling mining, the backfilling material is subjected to high stress for a long time, and its viscoelasticity has a significant impact on the roof control effect. This paper uses a large-scale bulk confinement test device to analyze the viscoelastic properties of gangue, establishes a high-precision fractional viscoelastic creep model, and identifies the gangue parameters. The established fractional viscoelastic model was used as the foundation model of the beam, and the roof model based on the fractional viscoelastic foundation was solved. The top deformation characteristics of elastic foundation and fractional foundation were compared and analyzed, and the time effect, viscoelastic effect, and order effect of the fractional order viscoelastic foundation beam were discussed. The results show that the viscosity of gangue increased under the action of deep high stress. As time increased, the roof deformation also increased. In order to more effectively control the long-term deformation of the roof, the viscosity coefficient of the backfilling material should be greater than 20 MPa. This research provides relevant guidance for the requirements of backfilling materials for deep backfilling mining and the prediction of long-term dynamic deformation of the roof in underground excavations.

Viscoelastic behavior on composite beam using nonlinear creep model

2007 ◽  
Vol 7 (5) ◽  
pp. 355-376
Author(s):  
Sung-Yeop Jung ◽  
Nam-Il Kim ◽  
Dong Ku Shin
Keyword(s):  
Composite Beam ◽  
Viscoelastic Behavior ◽  
Creep Model ◽  
Nonlinear Creep

Derailment Analysis of High-Speed Railway Vehicle Bogies

2011 ◽  
Vol 110-116 ◽  
pp. 186-195 ◽  
Author(s):  
Yung Chang Cheng ◽  
Chern Hwa Chen ◽  
Che Jung Yang
Keyword(s):  
High Speed ◽  
Lateral Displacement ◽  
Vertical Displacement ◽  
Creep Model ◽  
Railway Vehicle ◽  
Vehicle Speed ◽  
Nonlinear Creep ◽  
Bogie Frame ◽  
Suspension Parameters ◽  
Yaw Angle

Based on the heuristic nonlinear creep model, the nonlinear coupled differential equations of the motion of a 12 degree-of-freedom (12-DOF) bogie system which takes account of the lateral displacement, vertical displacement, the roll angle and the yaw angle of the each wheelset and the bogie frame, moving on curved tracks are derived. The nonlinear creep forces and moments are constructed via the saturation constant of the nonlinear creep model in completeness. The effect of the suspension parameters of a bogie system on the derailment quotient is investigated. Results obtained in this study show that the derailment quotient of a bogie system increases as the vehicle speed increases. In addition, the derailment quotient of a bogie system is generally decreased with the increasing values of suspension parameters.

Study on Nonlinear Viscoelasto-Plastic Creep Model of Deep Soft Rock

2012 ◽  
Vol 430-432 ◽  
pp. 168-172 ◽  
Author(s):  
Yan Chun Wang ◽  
Yong Yan Wang
Keyword(s):  
Least Squares Method ◽  
Soft Rock ◽  
Creep Model ◽  
Nonlinear Creep ◽  
Test Results ◽  
Mechanical Behaviors ◽  
Exponential Equation ◽  
Creep Stage ◽  
Three Stages ◽  
Plastic Creep

Based on the mechanical behaviors of deep soft rock at the accelerating creep stage, a nonlinear rheological cell containing exponential equation replaces classic linear cell, a new nonlinear viscoelasto-plastic creep model of deep soft rock is established on the basis of Nishihara model, and the model can describe the three stages of rock nonlinear creep. Using the least squares method of Matlab to investigate test results, the result shows the new nonlinear creep model accords better with the creep test curves, and verify correctness of the new model.

scholarly journals Study on Nonlinear Damage Creep Model for Rocks under Cyclic Loading and Unloading

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Liangliang Zhang ◽  
Xiaojian Wang
Keyword(s):  
Cyclic Loading ◽  
Superposition Principle ◽  
Three Dimensional ◽  
Creep Model ◽  
Model Parameters ◽  
Nonlinear Creep ◽  
Cyclic Loading And Unloading ◽  
In Series ◽  
Loading And Unloading ◽  
Stress States

To determine the nonlinear creep characteristics of rocks under cyclic loading and unloading conditions, a nonlinear Kelvin model and damage viscoplastic model are proposed. The models are connected in series with a linear elastic body to establish a nonlinear damage creep model. The differential damage constitutive equations of the proposed creep model under one-dimensional and three-dimensional stress states are derived based on the creep mechanics and elasticity theory. The damage and unloading creep equations are then obtained based on the superposition principle, and a simple and feasible method for determining the model parameters is determined. Finally, the step cyclic loading and unloading creep test data for lherzolite and limestone are used to verify the rationality and feasibility of the nonlinear damage creep model. The results show that the theoretical creep curves of the nonlinear damage creep model are consistent with the experimental curves which indicates that the proposed model can not only determine the creep properties of lherzolite and limestone under cyclic loading and unloading but also determine the nonlinear characteristics of rocks in the transient and steady-state creep stages and particularly within the accelerating creep stage.

Nonlinear creep model of salt rock used for displacement prediction of salt cavern gas storage

2022 ◽  
Vol 48 ◽  
pp. 103951
Author(s):  
Junbao Wang ◽  
Qiang Zhang ◽  
Zhanping Song ◽  
Shijin Feng ◽  
Yuwei Zhang
Keyword(s):  
Gas Storage ◽  
Creep Model ◽  
Nonlinear Creep ◽  
Salt Rock ◽  
Displacement Prediction ◽  
Salt Cavern ◽  
Salt Cavern Gas Storage

Running Safety and Comfort Analysis of Railway Vehicles Moving on Curved Tracks

2014 ◽  
Vol 14 (04) ◽  
pp. 1450004 ◽  
Author(s):  
Yung-Chang Cheng ◽  
Chin-Te Hsu
Keyword(s):  
Degrees Of Freedom ◽  
Lateral Displacement ◽  
Equations Of Motion ◽  
Creep Model ◽  
Railway Vehicle ◽  
Nonlinear Creep ◽  
Running Safety ◽  
Comfort Index ◽  
Vertical Displacements ◽  
Index Formulas

Using a heuristic linear creep model, this study derives the governing differential equations of motion for the railway vehicle traveling on curved tracks. The railway vehicle is modeled as a car system with 27 degrees-of-freedom (DOFs), taking into account the lateral and vertical displacements, roll and yaw angles of the wheelsets and truck frames, as well as the lateral displacement, roll and yaw angles of the car body. The effects of railway vehicle speeds on the derailment quotients and offload factors related to running safety are evaluated by both the linear and nonlinear creep models for various radii of curved tracks. Using the Sperling and modified Sperling index formulas, the effects of railway vehicle speeds on lateral riding quality and comfort are illustrated for the two models with various radii of curved tracks. Furthermore, the effects of railway vehicle speeds on the lateral Sperling comfort index of the 27-DOF car model are presented and compared for various suspension parameters. Finally, the acceptable region for riding quality and comfort are drawn.

Sign in / Sign up

Export Citation Format

Share Document