The Method of Establishing Model for Describing the Structural Constitutive Relationship of Desert Sand under Moving Vehicle

2012 ◽  
Vol 178-181 ◽  
pp. 2815-2819
Author(s):  
Wei Wei Lv ◽  
Liang Gu ◽  
Xue Tao Huang
Keyword(s):  
Constitutive Model ◽  
Soil Mechanics ◽  
Confining Pressure ◽  
Constitutive Relationship ◽  
Moving Vehicle ◽  
Military Vehicles ◽  
Desert Sand ◽  
Strength And Deformation ◽  
Relationship Of ◽  
Rock And Soil

In this paper, the way of setting up the vehicle structural constitutive model is introduceded. With the desert soil three triaxial test data of rock and soil mechanics, the soil structural quantitative parameter ( strain comprehensive structure potential ) is introduced into the soil strength and deformation characteristics analysis.Under the same confining pressure the stress-strain curves of different water content of sand have the same tendency. Through the method of setting up the Duncan-Chang model,structural constitutive model of sand is constructed and the parameters of the model are obtained by testing. The research can provide reference for vehicles and military vehicles to improve crossing through the desert sand.

scholarly journals Failure Criteria and Constitutive Relationship of Lightweight Aggregate Concrete under Triaxial Compression

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 507
Author(s):  
Peihuan Ye ◽  
Yuliang Chen ◽  
Zongping Chen ◽  
Jinjun Xu ◽  
Huiqin Wu
Keyword(s):  
Triaxial Compression ◽  
Lightweight Aggregate ◽  
Confining Pressure ◽  
Failure Criteria ◽  
Constitutive Relationship ◽  
Lightweight Aggregate Concrete ◽  
Stress Strain ◽  
Aggregate Concrete ◽  
Stress Theory ◽  
Relationship Of

This paper investigates the compression behavior and failure criteria of lightweight aggregate concrete (LAC) under triaxial loading. A total of 156 specimens were tested for three parameters: concrete strength, lateral confining pressure and aggregate immersion time, and their effects on the failure mode of LAC and the triaxial stress-strain relationship of LAC is studied. The research indicated that, as the lateral constraint of the specimen increases, the failure patterns change from vertical splitting failure to oblique shearing failure and then to indistinct traces of damage. The stress-strain curve of LAC specimens has an obvious stress plateau, and the curve no longer appears downward when the confining pressure exceeds 12 MPa. According to the experimental phenomenon and test data, the failure criterion was examined on the Mohr–Coulomb theory, octahedral shear stress theory and Rendulic plane stress theory, which well reflects the behavior of LAC under triaxial compression. For the convenience of analysis and application, the stress-strain constitutive models of LAC under triaxial compression are recommended, and these models correlate well with the test results.

A Constitutive Model for Thixotropic Plastic Forming of Composites

2010 ◽  
Vol 154-155 ◽  
pp. 690-693 ◽  
Author(s):  
Hong Yan ◽  
Jian Jin Wang ◽  
Fa Yun Zhang
Keyword(s):  
Constitutive Model ◽  
Solid Metal ◽  
Constitutive Relationship ◽  
Practical Significance ◽  
Forecast Precision ◽  
Plastic Forming ◽  
Nonlinear Regression Method ◽  
Semi Solid ◽  
Relationship Of ◽  
Good Agreement

A new constitutive model for semi-solid composites forming was derived with analyzing constitutive relationships of semi-solid metal and composites forming. Parameters in the constitutive model were determined by the multiple nonlinear regression method. A constitutive relationship of semi-solid SiCp/AZ61 composites thixotropic plastic forming was proposed. The calculated results were good agreement with the experimental ones. The proposed constitutive model has the higher forecast precision and practical significance. The construction of constitutive model provides references for the thixotropic forming theory, simulation and technology.

Experimental Research on the Stress - Strain Curve of Regional Confined Concrete under Single Axial Press

2014 ◽  
Vol 584-586 ◽  
pp. 1289-1292
Author(s):  
Guo Liang Zhu
Keyword(s):  
Mechanical Properties ◽  
Theoretical Analysis ◽  
Constitutive Model ◽  
Theoretical Basis ◽  
Strain Curve ◽  
Confined Concrete ◽  
Constitutive Relationship ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Relationship Of

Regional confined concrete is base on confined concrete. It is the theory and application of a new attempt and development on confined concrete. To apply it to the actual project, we need to research mechanical properties and establish constitutive relationship of regional confined concrete. According to the research, we had carried on a series of tests, founded the stress-strain constitutive model of regional confined concrete under single axial press. The accuracy of theoretical analysis were more fully verified , and a theoretical basis for the application was provided.

Research on Compressive Stress - Strain Relationship of Fiber Reinforced Concrete

2010 ◽  
Vol 168-170 ◽  
pp. 384-392 ◽  
Author(s):  
Tie Cheng Wang ◽  
Hai Long Zhao ◽  
Jin Jin Hao ◽  
Jian Quan Zu
Keyword(s):  
Reinforced Concrete ◽  
Constitutive Model ◽  
Engineering Application ◽  
Fiber Reinforced Concrete ◽  
Constitutive Relationship ◽  
Peak Strain ◽  
Test Results ◽  
Fiber Reinforced ◽  
Damage Constitutive Model ◽  
Relationship Of

The marked brittleness of concrete could be overcome by the addition of fibers. This paper experimentally investigated the mechanical properties and constitutive relationship of different fiber reinforced concrete. It is shown from the results that the compressive strength and peak strain of concrete with fiber have little improvement, but the ultimate strain, deformation capacity, toughness and energy dissipation capacity are improved greatly. The damage constitutive model recommended by the emendatory code for design of concrete structure (appendix C) (GB50010-2002) is applied for calculations and analyses according to the test results. The damage constitutive model and non-elastic constitutive model of different fiber reinforced concrete are established based on the test results. It is indicated from the analyses that the constitutive models established in this paper are in accordance with the characteristic of the fiber reinforced concrete in loading process. The damage constitutive model in appendix C in code could be applied directly in some low precision calculation and engineering application.

scholarly journals Investigation of the Constitutive Model of W/PMMA Composite Microcellular Foams

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1136 ◽  
Author(s):  
Yuxuan Zhu ◽  
Guoqiang Luo ◽  
Ruizhi Zhang ◽  
Qiwen Liu ◽  
Yi Sun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Constitutive Model ◽  
Constitutive Relationship ◽  
Microcellular Foam ◽  
Melt Mixing ◽  
Static Compression ◽  
Microcellular Foams ◽  
Static Mechanical ◽  
Relationship Of ◽  
Quasi Static Compression

Investigating the constitutive relationship of a material can provide better understanding of the mechanical properties of a material and has an irreplaceable effect on optimizing the performance of a material. This paper investigated a constitutive model for tungsten/polymethyl-methacrylate (W/PMMA) composite microcellular foams prepared by using melt mixing and supercritical carbon dioxide foaming. The stress-strain relationships of these foams with different W contents were measured under static compression. The elastic modulus and compressive strength values of the foams were remarkably greater than those of the pure PMMA foams: at a W content of 20 wt %, these values were increased by 269.1% and 123.9%, respectively. Based on the Maxwell constitutive model, the relevant coefficients were fitted according to the experimental data of different relative densities and W contents in quasi-static compression. According to the numerical relationships between the relevant coefficients and the relative densities and W contents, the quasi-static mechanical constitutive model of W/PMMA composite microcellular foams with W contents of 0~60 wt % and relative densities of 0.15~0.55 were predicted. This study provided basic data for the optimal design of the W/PMMA composite microcellular foams and proposed a method for investigating the mechanical properties of composite microcellular foam materials.

scholarly journals Constitutive Modeling of Physical Properties of Coastal Sand during Tunneling Construction Disturbance

2021 ◽  
Vol 9 (2) ◽  
pp. 167
Author(s):  
Jian-Feng Zhu ◽  
Hong-Yi Zhao ◽  
Ri-Qing Xu ◽  
Zhan-You Luo ◽  
Dong-Sheng Jeng
Keyword(s):  
Constitutive Model ◽  
Constitutive Relationship ◽  
Initial Void Ratio ◽  
Coastal Cities ◽  
Disturbed State Concept ◽  
Strain Relationship ◽  
Internal Angle ◽  
Concept Theory ◽  
Relationship Of ◽  
Disturbance Function

This paper presents a simple but workable constitutive model for the stress–strain relationship of sandy soil during the process of tunneling construction disturbance in coastal cities. The model was developed by linking the parameter K and internal angle φ of the Duncan–Chang model with the disturbed degree of sand, in which the effects of the initial void ratio on the strength deformation property of sands are considered using a unified disturbance function based on disturbed state concept theory. Three cases were analyzed to investigate the validity of the proposed constitutive model considering disturbance. After validation, the proposed constitutive model was further incorporated into a 3D finite element framework to predict the soil deformation caused by shield construction. It was found that the simulated results agreed well with the analytical solution, indicating that the developed numerical model with proposed constitutive relationship is capable of characterizing the mechanical properties of sand under tunneling construction disturbance.

scholarly journals The Establishment of Segmented Constitutive Relationship of Coal under Triaxial Compression: Take the No. 3 Coal of Xinhe Colliery as an Example

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yongjie Yang ◽  
Yang Zhang ◽  
Tianli Zhang
Keyword(s):  
Mechanical Test ◽  
Triaxial Compression ◽  
Failure Process ◽  
Confining Pressure ◽  
Test System ◽  
Constitutive Relationship ◽  
Peak Strain ◽  
Deformation Stage ◽  
Triaxial Compressive Strength ◽  
Relationship Of

Constitutive relationship of coal under triaxial compression must be determined during solving the theoretical calculation and numerical simulation about coal body failure. This paper carried out the conventional triaxial compression test on No. 3 coal of Xinhe Colliery using the MTS815.03 servo-controlled rock mechanical test system. The results indicate that the failure process of coal can be divided into 5 stages: densification stage, apparent linear elastic deformation stage, accelerated inelastic deformation stage, fracture and developing stage, and plasticity flow stage. Within the test confining pressure (20 MPa), the peak strain of coal is approximately linearly positively correlated with the confining pressure. The relationship between elastic modulus of coal and confining pressure is quadratic polynomial. The triaxial compressive strength and residual strength of coal are approximately linearly positively correlated with confining pressure. The constitutive relationship model of coal can be simplified as the four segments of straight line model of “elastic–plastic hardening–plastic softening–residual perfectly plastic.” Through fitting calculation of test data, the segmented constitutive equation of coal can be obtained, and the every segment span of strain.

A Dynamic Constitutive Model of Saturated Remolded Loess

2013 ◽  
Vol 535-536 ◽  
pp. 557-560
Author(s):  
Zheng Hua Xiao ◽  
Hong Jian Liao ◽  
Akenjiang Tuohuti ◽  
Bo Han
Keyword(s):  
Constitutive Model ◽  
Rational Function ◽  
Damping Ratio ◽  
Constitutive Relationship ◽  
Triaxial Tests ◽  
Hysteresis Curve ◽  
Constant Amplitude ◽  
Symmetric Loading ◽  
Relationship Of ◽  
Curve Equation

A series of dynamic triaxial tests were performed to study a dynamic constitutive relationship of saturated remolded loess under cyclic loading. A new dynamic rational function constitutive model based on damping ratio was proposed. The model assumed the calculated damping ratio equaled to the measured damping ratio and the hysteresis curve was consisted by two curves accorded with rational function. This not only ensured that the theoretical hysteresis curve reflected the real energy dissipation of remolded loess but also retained the high calculated efficiency of this model. The hysteresis curve equation under constant amplitude symmetric loading was deduced and results of this model were verified by the tests.

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