Fracture and fragmentation of dolomite rock using the JH-2 constitutive model: Parameter determination, experiments and simulations

Block-in-matrix-rocks (bimrocks) are very complicated geological masses that cause many challenging problems during the design and construction of engineering projects, such as parameter determination and landsliding. Successful engineering design and construction depends on a suitable constitutive model and reliable design parameters for geological masses. In this paper, the vibration attenuation signal of welded bimrocks was obtained and studied using resonance test technology. Combined with a uniaxial compression test, a constitutive model was proposed to describe the mechanical behavior of welded bimrocks. On this basis, the relations between the dynamic elastic modulus and the physical parameters of bimrocks were established, which included macroscopic mechanical parameters and damage constitutive parameters. Consequently, a new technological process was proposed to provide quick identification of the mechanical properties of welded bimrocks. The results indicate that the dynamic elastic modulus is highly correlated with the rock block proportion (RBP) and uniaxial compression strength (UCS). It is an effective parameter to predict the strength of the bimrocks with high RBPs. Additionally, the proposed constitutive model, which is based on damage theory, can accurately simulate the strain softening behavior of the bimrocks. Combining the resonant frequency technology and the proposed constitutive model, the complete stress strain curve can be obtained in a rapid and accurate manner, which provides a further guarantee of the stability and safety of underground engineering.

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Parameter Determination for the Constitutive Model Lubby2 and Strength Model Hou Based on Laboratory Tests on Rock Salt Samples from Jintan, P.R. China

Springer Series in Geomechanics and Geoengineering - Clean Energy Systems in the Subsurface: Production, Storage and Conversion ◽

10.1007/978-3-642-37849-2_24 ◽

2013 ◽

pp. 293-304 ◽

Cited By ~ 2

Author(s):

Juan Zhao ◽

Michael Zhengmeng Hou ◽

Wei Xing

Keyword(s):

Constitutive Model ◽

Rock Salt ◽

Laboratory Tests ◽

Parameter Determination ◽

Strength Model

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A Unified Constitutive Model With Optimized Parameters for Base and Diffusion Bonded Alloy 800H

Volume 3: Design and Analysis ◽

10.1115/pvp2020-21498 ◽

2020 ◽

Author(s):

Heramb P. Mahajan ◽

Tasnim Hassan

Keyword(s):

Elevated Temperature ◽

Power Plant ◽

Nuclear Power Plant ◽

Constitutive Model ◽

Nuclear Power ◽

Parameter Determination ◽

Alloy 800H ◽

Inelastic Analysis ◽

Creep Fatigue ◽

Plant Components

Abstract Current ASME Section III, Division 5 code provides elastic, simplified inelastic and inelastic analysis options for designing nuclear power plant components for elevated temperature service. These analyses methods may fail to capture the complex creep-fatigue response and damage accumulation in materials at elevated temperatures. Hence, for analysis and design of the nuclear power plant components at elevated temperature, a full inelastic analysis that can simulate creep-fatigue responses may be needed. Existing ASME code neither provides guidelines for using full inelastic analysis nor recommends the type of constitutive model to be used. Hence, a unified rate-dependent constitutive model incorporating a damage parameter will be developed, and its parameters for base metal will be determined. In addition, a full inelastic analysis methodology using this model to analyze the creep-fatigue performance of components for nuclear power applications will be developed. Base metal 800H (BM800H) data are collected from literature to determine constitutive material model parameters. The parameter determination methodology for a constitutive model is discussed. The optimized parameter set for BM 800H at different temperatures will be presented in the paper. Recommendations are provided on the constitutive model selection and its parameter determination techniques. In the future, this work will be continued for diffusion bonded Alloy 800H (DB800H) material, and obtained parameters will be compared.

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Study on Dynamic Constitutive Model of Weakly Consolidated Soft Rock in Western China

Shock and Vibration ◽

10.1155/2020/8865013 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13

Author(s):

Lei Wang ◽

Hongming Su ◽

Yue Qin ◽

Shiguan Chen

Keyword(s):

Constitutive Equation ◽

Constitutive Model ◽

Split Hopkinson Pressure Bar ◽

Soft Rock ◽

Frozen Soil ◽

Constitutive Relationship ◽

Western China ◽

Parameter Determination ◽

Engineering Practice ◽

The Impact

To obtain the impact mechanical response and establish the dynamic damage constitutive relationship of frozen sandstone at low temperature conditions, the impact test of Cretaceous red sandstone under different temperatures was conducted using a split Hopkinson pressure bar (SHPB) device. According to the characteristics of the stress-strain curves obtained by the test, a constitutive model considering the damage effect, temperature effect, and strain rate effect was established, which was improved by Zhu–Wang–Tang (Z–W–T) constitutive model. It was proved that the fitting curves of constitutive equation were in good agreement with the test curves. The fluctuation amplitude of fitting error was controlled within ±4 MPa. The physical meaning of each parameter of the constitutive model is clear, and most of them are fixed values. The selection range of variable parameters and the related change rules are confirmed, which improves the practicability of constitutive model. The constitutive equation can well describe the nonlinear features of this kind of frozen sandstone under impact loading. It was also found that the constitutive equation was applicable to express the dynamic mechanical properties of rock-like materials such as hard rock, soft rock, frozen soil, raw coal, and concrete. It can be referred to the parameter determination method in this paper to study and determine the parameters, reduce the difficulty of parameter selection, and improve the practicability of the constitutive model and parameters, so as to guide the engineering practice better.

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