scholarly journals Creep damage model of rock with varying-parameter under the step loading and unloading conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guanghe Li ◽  
Yanting Wang ◽  
Dong Wang ◽  
Xiaoxu Yang ◽  
Laigui Wang ◽  
...  
Keyword(s):  
Damage Model ◽  
Model Fitting ◽  
Creep Damage ◽  
Model Parameters ◽  
Creep Characteristics ◽  
Study Results ◽  
In Series ◽  
Loading And Unloading ◽  
Step Loading ◽  
Creep Damage Model

AbstractThe creep characteristics of rock under step loading and unloading conditions were investigated in this study. Based on the generalized Burgers model, the total strain of rock was decomposed into elastic, viscoelastic, varying-parameter viscoelastic, and viscoplastic strains considering the damage. The four strains were connected in series to establish a new varying-parameter creep damage model that can characterize the creep characteristics of rock under step loading and unloading conditions as well as identify and verify the model parameters. The study results showed that the varying-parameter creep damage model could better describe the creep characteristics of rock under step loading and unloading conditions, significantly the non-linear both the strain and time of attenuation creep and accelerated creep. The model fitting curve was highly consistent with the experimental data, and the correlation coefficient R2 was greater than 0.98, which thoroughly verified the accuracy and rationality of the model. These findings can provide theoretical support for analyzing the deformation and long-term stability of rock and soil.

scholarly journals A Creep Damage Constitutive Model for a Rock Mass with Nonpersistent Joints under Uniaxial Compression

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Shuran Lv ◽  
Wanqing Wang ◽  
Hongyan Liu
Keyword(s):  
Rock Mass ◽  
Constitutive Model ◽  
Mechanical Behavior ◽  
Uniaxial Compression ◽  
Damage Model ◽  
Creep Damage ◽  
Model Parameters ◽  
Damage Constitutive Model ◽  
Set Up ◽  
Creep Damage Model

As part of the rock mass, both the mesoscopic and macroscopic flaws will affect the creep mechanical behavior of the rock mass with nonpersistent joints. This study focuses on this kind of rock mass and establishes a creep damage model to account for the effect of the joint on its creep mechanical behavior. First, on basis of analyzing the rock element creep mechanism and the typical creep deformation curve, a new creep damage constitutive model for the rock element is set up by introducing the damage theory and Kachanov damage evolution law into the classic creep constitutive model such as J body model. Second, the determination method of the proposed model parameters is studied in detail. Third, the calculation method of the macroscopic damage caused by the joint proposed by others is introduced which can consider the joint geometry, strength, and deformation parameters at the same time. Finally, the creep damage model for the rock mass with nonpersistent joints under uniaxial compression is proposed. The calculation examples indicate that it can present the effect of the joint on the rock mass creep mechanical behavior.

scholarly journals Multi-Step Loading Creep Behavior of Red Sandstone after Thermal Treatments and a Creep Damage Model

Energies ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 212 ◽  
Author(s):  
Sheng-Qi Yang ◽  
Bo Hu ◽  
Pathegama Ranjith ◽  
Peng Xu
Keyword(s):  
Creep Behavior ◽  
Damage Model ◽  
Creep Damage ◽  
Thermal Treatments ◽  
Red Sandstone ◽  
Step Loading ◽  
Creep Damage Model

Non-linear creep damage model of sandstone under freeze-thaw cycle

2021 ◽  
Vol 28 (3) ◽  
pp. 954-967
Author(s):  
Jie-lin Li ◽  
Long-yin Zhu ◽  
Ke-ping Zhou ◽  
Hui Chen ◽  
Le Gao ◽  
...  
Keyword(s):  
Damage Model ◽  
Creep Damage ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Linear Creep ◽  
Non Linear ◽  
Freeze Thaw Cycle ◽  
Creep Damage Model

An improved nonlinear damage model of rocks considering initial damage and damage evolution

2020 ◽  
Vol 29 (7) ◽  
pp. 1117-1137 ◽  
Author(s):  
Wenlin Feng ◽  
Chunsheng Qiao ◽  
Shuangjian Niu ◽  
Zhao Yang ◽  
Tan Wang
Keyword(s):  
Damage Evolution ◽  
Least Squares Method ◽  
Damage Model ◽  
Creep Damage ◽  
Secondary Creep ◽  
Nonlinear Creep ◽  
Creep Failure ◽  
Initial Damage ◽  
Nonlinear Damage Model ◽  
Creep Damage Model

The experimental results show that the creep properties of the rocks are affected by the initial damage, and the damage evolution also has a significant impact on the time-dependent properties of the rocks during the creep. However, the effects of the initial damage and the damage evolution are seldom considered in the current study of the rocks' creep models. In this paper, a new nonlinear creep damage model is proposed based on the multistage creep test results of the sandstones with different damage degrees. The new nonlinear creep damage model is improved based on the Nishihara model. The influences of the initial damage and the damage evolution on the components in the Nishihara model are considered. The creep damage model can not only describe the changes in three creep stages, namely, the primary creep, the secondary creep, and the tertiary creep, but also reflect the influence of the initial damage and the damage evolution on creep failure. The nonlinear least squares method is used to determine the parameters in the nonlinear creep damage model. The consistency between the experimental data and the predicted results indicates the applicability of the nonlinear damage model to accurately predict the creep deformation of the rocks with initial damage.

scholarly journals The Creep-Damage Model of Salt Rock Based on Fractional Derivative

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2349 ◽  
Author(s):  
Hongwei Zhou ◽  
Di Liu ◽  
Gang Lei ◽  
Dongjie Xue ◽  
Yang Zhao
Keyword(s):  
Fractional Derivative ◽  
Creep Test ◽  
Damage Model ◽  
Creep Damage ◽  
Uniaxial Stress ◽  
Radioactive Waste Disposal ◽  
Creep Process ◽  
Salt Rock ◽  
Damage Process ◽  
Creep Damage Model

The use of salt rock for underground radioactive waste disposal facilities requires a comprehensive analysis of the creep-damage process in salt rock. A computer-controlled creep setup was employed to carry out a creep test of salt rock that lasted as long as 359 days under a constant uniaxial stress. The acoustic emission (AE) space-time evolution and energy-releasing characteristics during the creep test were studied in the meantime. A new creep-damage model is proposed on the basis of a fractional derivative by combining the AE statistical regularity. It indicates that the AE data in the non-decay creep process of salt rock can be divided into three stages. Furthermore, the authors propose a new creep-damage model of salt rock based on a fractional derivative. The parameters in the model were determined by the Quasi-Newton method. The fitting analysis suggests that the new creep-damage model provides a precise description of full creep regions in salt rock.

A nonlinear creep damage model for salt rock

2018 ◽  
Vol 28 (5) ◽  
pp. 758-771 ◽  
Author(s):  
Fei Wu ◽  
Jie Chen ◽  
Quanle Zou
Keyword(s):  
Test Data ◽  
Damage Model ◽  
Creep Damage ◽  
Nonlinear Creep ◽  
Salt Rock ◽  
Creep Tests ◽  
Nonlinear Constitutive Equation ◽  
Damage Constitutive Model ◽  
Creep Damage Model ◽  
Actual Stress

In the creep tests, stress is no longer a constant and increases gradually under the influence of damage occurring during accelerating creep, which is a slow-loading process rather than a conventional creep. With the accumulation of the damage over time, the actual stress increases greatly. The increased actual stress not only generates loading strain but also causes the steady creep rate to rise. This coupling possibly explains why salt rock presents nonlinear accelerating characteristics at the accelerating creep stage. In this work, the constraint of the present creep concept was overcome by assuming that the acceleration creep phase is a coupling process of loading and creeping. Furthermore, we demonstrate that the total strain in this phase is equal to the sum of loading strain and creeping strain. A new nonlinear constitutive equation for creep was then derived, and the mechanisms underlying the nonlinear accelerating characteristics emerging at the stage of accelerating creep are further explained. A step-loading experiment on salt rock was performed for a period of six months. The characteristics of accelerating creep appeared in the last step of loading. This new nonlinear creep damage constitutive model was used to fit and analyze the test data. Obtained results show that this model fits well to these test data and also favorably represents the nonlinear characteristics of accelerating creep, thus supporting the model’s validity.

Peridynamics Implementation of Liu Murakami Creep Damage Model in Moose Framework

2021 ◽  
Author(s):  
Erdogan Madenci ◽  
Pranesh Roy ◽  
Deepak Kumar Behera
Keyword(s):  
Damage Model ◽  
Creep Damage ◽  
Creep Damage Model
Sign in / Sign up

Export Citation Format

Share Document