scholarly journals Application of Base Force Element Method to Mesomechanics Analysis for Concrete

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Yijiang Peng ◽  
Yao Wang ◽  
Qing Guo ◽  
Junhua Ni
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fracture Process ◽  
Damage Mechanics ◽  
Hardened Cement ◽  
Aggregate Model ◽  
Random Aggregate ◽  
Random Aggregate Model ◽  
Force Element ◽  
Element Method

The base force element method (BFEM) on damage mechanics is used to analyze the compressive strength, the size effects of compressive strength, and fracture process of concrete at mesolevel. The concrete is taken as three-phase composites consisting of coarse aggregate, hardened cement mortar, and interfacial transition zone (ITZ) on mesolevel. The random aggregate model is used to simulate the mesostructure of concrete. The mechanical properties and fracture process of concrete under uniaxial compression loading are simulated using the BFEM on damage mechanics. The simulation results agree with the test results. This analysis method is the new way for investigating fracture mechanism and numerical simulation of mechanical properties for concrete.

Simulation of Numerical Test of Concrete Microscopic Structure by Second-Order Manifold Method

2013 ◽  
Vol 477-478 ◽  
pp. 968-971 ◽  
Author(s):  
Yan Zhao ◽  
Guo Xin Zhang ◽  
Hai Feng Li
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Fracture Process ◽  
Shear Failure ◽  
Numerical Test ◽  
Aggregate Model ◽  
The Monte Carlo Method ◽  
Random Aggregate ◽  
Random Aggregate Model ◽  
Numerical Manifold

To simulate the numerical test of concrete, the random aggregate model according to the Monte Carlo method and Fuller Graded Formula is carried out based on the assumption that the concrete is a multi-phases composite material composed of matrix. By adding the function of tracing the propagation of cracks,the Numerical Manifold Method proposed by Shi Genhua is developed which can simulate both the discontinuity of block system and the tensile or shear failure of intact block. The random aggregate model according to the Monte Carlo method and Fuller Graded Formula is carried out, and the concrete fracture process is simulated by the NMM. The strength and failure pattern are in good agreement with the experimental data, which shows that the method put forward and the program developed in this paper can effectively simulate the fracture process of concrete composed of multi-cracks.

Simulation Study of Fracture Process of Concrete Mesoscopic Structure by Manifold Method

2011 ◽  
Vol 243-249 ◽  
pp. 875-878
Author(s):  
Yan Zhao ◽  
Guo Xin Zhang ◽  
Xiao Chuan Wu ◽  
Fu Xin Chai
Keyword(s):  
Fracture Process ◽  
Shear Failure ◽  
Concrete Fracture ◽  
Aggregate Model ◽  
The Monte Carlo Method ◽  
Mesoscopic Structure ◽  
Random Aggregate ◽  
Random Aggregate Model ◽  
Numerical Manifold ◽  
Good Agreement

On the assumption that the concrete is a multi-phases composite material composed of matrix, aggregate and the bonding interface, the failure progress of concrete is simulated. It requires that numerical method not only can simulate forces and stresses, the failure growth and contacts, but also can simulate the discontinuities such as joints and cracks，the large deformation after the failure and the propagation of multi-cracks. By adding the function of tracing the propagation of cracks，the Numerical Manifold Method proposed by Shi Genhua is developed which can simulate both the discontinuity of block system and the tensile or shear failure of intact block. The random aggregate model according to the Monte Carlo method and Fuller Graded Formula is carried out, and the concrete fracture process is simulated by the NMM. The strength and failure pattern are in good agreement with the experimental data, which shows that the method put forward and the program developed in this paper can effectively simulate the fracture process of concrete composed of multi-cracks.

Analysis of Mechanical Performance of Crumb Rubber Concrete by Different Aggregate Shape under Uniaxial Compression on Mesoscopic

2011 ◽  
Vol 462-463 ◽  
pp. 219-222 ◽  
Author(s):  
Gen Quan Zhong ◽  
Yong Chang Guo ◽  
Li Juan Li ◽  
Feng Liu
Keyword(s):  
Mechanical Properties ◽  
Uniaxial Compression ◽  
Crumb Rubber ◽  
Aggregate Model ◽  
Stress Strain ◽  
Random Aggregate ◽  
Random Aggregate Model ◽  
Crumb Rubber Concrete ◽  
Aggregate Shape ◽  
Rubber Concrete

From micro perspective, crumb rubber concrete (CRC) is viewed as a composite consisting of mortar matrix, aggregates and rubber particle. In this paper, based on random aggregate model with different aggregate shape in planar, the mechanical properties of CRC using linear Mohr-coulomb constitutive relation are studied by nonlinear finite element method under uniaxial compression on mesoscopic. The number of random aggregates is calculated in two-dimension by Walraven formula. Circular random aggregate model, elliptic random aggregate model and polygonal random aggregate model are established. Stress-strain curves under varieties of conditions are derived and compared with the test results. The results show that the simulative stress-strain curve fit the reality very much. In the numerical analysis, the aggregate shape has little effect on the mechanical properties of CRC.

The Impact of Aggregates Distribution on Concrete Failure

2012 ◽  
Vol 594-597 ◽  
pp. 929-932 ◽  
Author(s):  
Min Du ◽  
Ping Gao ◽  
Fa Jia Chen
Keyword(s):  
Mechanical Properties ◽  
Failure Process ◽  
Aggregate Model ◽  
Extended Finite Element ◽  
Fracture Modes ◽  
Concrete Failure ◽  
Random Aggregate ◽  
Concrete Mechanical Properties ◽  
Random Aggregate Model ◽  
The Impact

As the key component, the aggregates have a significant impact on the concrete’s mechanical properties and fracture modes. To study the impact of aggregates distribution on concrete failure, the extended finite element method (XFEM) is adopted to simulate the mesostructure failure process by virtue of random aggregate model under uniaxial tension. The result shows that aggregates distribution has little effect on the concrete mechanical properties, but aggregates distribution effect fracture modes.

scholarly journals Damage Simulation of a Random Aggregate Model Induced by Microwave under Different Discontinuous Ratios and Exposure Times

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Yang Tang ◽  
Guobin Xu ◽  
Chunlai Qu ◽  
Liying Sun ◽  
Yu Duan
Keyword(s):  
Discrete Element Method ◽  
Discrete Element ◽  
Particle Flow Code ◽  
Aggregate Model ◽  
Two Phase ◽  
Random Aggregate ◽  
Random Aggregate Model ◽  
Damage Simulation ◽  
Radial Network ◽  
Element Method

A random aggregate algorithmic method and a numerical model for two-phase materials (composed of quartz and plagioclase) with different discontinuous ratios and irradiation times were studied based on the discrete element method using two-dimensional particle flow code (PFC2D). The results showed that this algorithm can simulate random irregular aggregate shapes. Furthermore, crack initiation and development and the coalescence process of microwave-induced material damage could be predicted using the discrete element method. After analysis of this study, the micro crack originated from the boundary of the high-absorption-phase plagioclase crystal and expanded around the plagioclase, extending into the quartz material. The crack morphology presented a radial network.

scholarly journals Mesoscopic Numerical Simulation of Fracture Process and Failure Mechanism of Concrete Based on Convex Aggregate Model

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Yijiang Peng ◽  
Xiyun Chen ◽  
Liping Ying ◽  
Ying Chen ◽  
Lijuan Zhang
Keyword(s):  
Numerical Simulation ◽  
Failure Mechanism ◽  
Fracture Process ◽  
Compressive Loading ◽  
Nonlinear Behavior ◽  
Heterogeneous Material ◽  
Specimen Size ◽  
Aggregate Model ◽  
Force Element ◽  
Element Method

To investigate the fracture process and failure mechanism of concrete subjected to uniaxial compressive loading, a new finite element method—the base force element method (BFEM)—was adopted in the modeling of numerical simulation. At mesoscale, concrete is considered as a three-phase heterogeneous material composed of aggregate particles, cement mortar, and the interfacial transition zones between the two phases. A two-dimensional random convex aggregate model was established using the principle of the area equivalence method. A multistage linear damage constitutive model that can describe nonlinear behavior of concrete under mechanical stress was proposed. The mechanical properties of concrete mesoscopic components are determined. The numerical simulation results indicate that the base force element method can be applied to predict the failure pattern of concrete under compressive loading, which have a good accordance with the available experiment data. The stress contour plots were given and used to analyze the failure mechanism of concrete. The effects of specimen size on the strength of concrete material were studied. It is found that compressive strength of concrete decreases as the specimen size increases. In addition, the influences of aggregate distribution, coarse aggregate content, and end friction on concrete performance are explored.

scholarly journals Application of Base Force Element Method to Mesomechanics Analysis for Recycled Aggregate Concrete

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yijiang Peng ◽  
Yinghua Liu ◽  
Jiwei Pu ◽  
Lijuan Zhang
Keyword(s):  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Triangular Element ◽  
Aggregate Model ◽  
Energy Principle ◽  
Aggregate Concrete ◽  
Tension Tests ◽  
Random Aggregate ◽  
Force Element ◽  
Element Method

The base force element method (BFEM) on potential energy principle is used to analyze recycled aggregate concrete (RAC) on mesolevel. The model of BFEM with triangular element is derived. The recycled aggregate concrete is taken as five-phase composites consisting of natural coarse aggregate, new mortar, new interfacial transition zone (ITZ), old mortar, and old ITZ on meso-level. The random aggregate model is used to simulate the mesostructure of recycled aggregate concrete. The mechanics properties of uniaxial compression and tension tests for RAC are simulated using the BFEM, respectively. The simulation results agree with the test results. This research method is a new way for investigating fracture mechanism and numerical simulation of mechanics properties for recycled aggregate concrete.

scholarly journals Effect of Ground Slag on Mechanical Properties of Concrete under Low Temperature

2021 ◽  
Vol 2109 (1) ◽  
pp. 012019
Author(s):  
Xuelian Yuan ◽  
Jie Hu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Compressive Strength ◽  
Low Temperature ◽  
Cement Paste ◽  
High Volume ◽  
Hardened Cement ◽  
Micro Structure ◽  
Hardened Cement Paste ◽  
Fracture Properties

Abstract Through using cube resisting compression test, fracture properties and micro-structure, the mechanical properties of high volume ground slag concrete under low temperature are studied in this paper. The results show that low temperature can improve the compressive strength of high volume ground slag concrete. And strength increased with the decreased of temperature. Low temperature can also improve the fracture energy and fracture toughness. Not only can ground slag reduce the content of calcium hydroxide in hardened cement paste, but ground slag can improve the compactness of hardened cement paste, reduce porosity and improve the strength of the interface.

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