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.

The Concrete Fracture Performance Response to the Interface Transition Zone Parameters Based on Mesoscopic Simulation

2012 ◽  
Vol 170-173 ◽  
pp. 3482-3486 ◽  
Author(s):  
Min Du ◽  
Liu Jin ◽  
Xiu Li Du ◽  
Yan Zhao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Fracture Energy ◽  
Transition Zone ◽  
Failure Process ◽  
Aggregate Model ◽  
Fracture Modes ◽  
Random Aggregate ◽  
Interface Transition Zone

The interface transition zone (ITZ) has a significant impact on the concrete’s mechanical properties and fracture modes. For the influence of ITZ’s strength and elastic modulus, the extended finite element method (XFEM) is adopted to simulate the mesostructure failure process by virtue of random aggregate model under uniaxial tension. The results show that ITZ’s strength and elastic modulus have a certain effect on the mechanical properties and fracture modes. With the tensile strength of ITZ increasing, the fractured modes transit from single coalescent crack to multiple non-coalescent cracks and the fracture energy increases, the ductility of concrete is enhanced. With the elastic modulus of ITZ increasing, the concrete’s elastic modulus increases, the tensile strength and the fracture energy decrease.

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 Mechanical Properties Base on Numerical Manifold Method

2011 ◽  
Vol 217-218 ◽  
pp. 1739-1742
Author(s):  
Yan Zhao ◽  
Guo Xin Zhang ◽  
Song Nan Ru ◽  
Fu Xin Chai
Keyword(s):  
Mechanical Performance ◽  
Numerical Test ◽  
Numerical Manifold Method ◽  
Aggregate Model ◽  
Deformation And Failure ◽  
Random Aggregate ◽  
Concrete Mechanical Properties ◽  
Random Aggregate Model ◽  
Mesoscopic Level ◽  
Numerical Manifold

In order to reflect the heterogeneity of concrete at mesoscopic level and simulate the mechanics response from the mesoscopic to macroscopical in the course of load, 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, and the material parameters are defined based on the test. In this paper, the Numerical Manifold Method introduced not only can correctly simulate stress, deformation and failure of concrete, but can simulate propagation of multi-cracks in the concrete, and failure plane growth can be searched by stress results automatically, so it can simulate the kind high discontinuous problem very well. On this basis, NMM is adopted to simulate the tests on concrete mechanical performance. The creation, propagation and fracture process of cracks in compression of concrete are present. The computational results are in good agreement with the experimental data.

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.

Numerical Dynamic Simulation for Three Phase Random Aggregate Model of Concrete

2012 ◽  
Vol 598 ◽  
pp. 393-399
Author(s):  
Chuan Guo Zhong ◽  
Fan Wang
Keyword(s):  
Impact Load ◽  
Plastic Material ◽  
Impact Damage ◽  
Failure Process ◽  
Model Material ◽  
Aggregate Model ◽  
Finite Element Program ◽  
Three Phase ◽  
Random Aggregate ◽  
The Impact

In this paper the concrete under impact load and failure mechanism was studied. Concrete was considered as a three-phase composite material: aggregate, cement mortar and interfacial transmission zone (ITZ).The simulation was based on random polyhedron aggregate model. Mortar and the transition zone were considered as the brittle fracture model material, and the aggregate was considered as plastic material. LS-DYNA finite element program was used to simulate concrete in SHPB experimental device under the impact damage process. It was showed that the reason of the final macro failure was the development of the microcrack, aggregate shape on concrete failure has a certain impact on the failure process.

Numerical Simulation of Meso-Damage Process of Concrete under Dynamic Load and CT Experiment Verification

2012 ◽  
Vol 174-177 ◽  
pp. 299-303
Author(s):  
Guang Yu Lei ◽  
Fa Ning Dang ◽  
Feng Pan
Keyword(s):  
Numerical Simulation ◽  
Dynamic Load ◽  
Failure Process ◽  
Displacement Curve ◽  
Aggregate Model ◽  
Damage And Fracture ◽  
Random Aggregate ◽  
Damage Process ◽  
Ct Test ◽  
The Impact

In mesoscopic level, concrete was taken as three-phase composites consisting of aggregate, bond and mortar. Use the Monte Carlo methods, establish random aggregate model of concrete and apply the concrete damage plasticity model. Judge the failure based on the load-displacement curve and then doing the numerical simulation to the specimen on the impact loads. Through CT test, get the CT images of various force stages of the concrete. Compare the damage process picture of the numerical simulation with CT test. Find the failure process of the numerical simulation is similar to the CT test. The results show that the model is right to simulate the damage and fracture of concrete which is under the dynamic load. It is established that the model of the method is feasible.

Study on the Three-Graded Random Aggregate Model of Concrete Beam with Initial Imperfection

2012 ◽  
Vol 505 ◽  
pp. 121-126
Author(s):  
Yuan Qin ◽  
Jun Rui Chai ◽  
Fa Ning Dang
Keyword(s):  
Concrete Beam ◽  
Impact Load ◽  
Initial Imperfection ◽  
Engineering Practice ◽  
Aggregate Model ◽  
Random Aggregate ◽  
Calculation Results ◽  
Damage Process ◽  
Random Aggregate Model ◽  
The Impact

In this paper, the three-graded random aggregate model of concrete beam is established by using the Monte Carlo method. And in order to close to the engineering practice, the initial imperfection is putted in to this model. Then the impact load is applied to the beam, and the numerical calculation is carried out, the results of numerical simulation and experiments of previous are compared. It is found that the damage process of concrete and calculation results are similar to the experimental results of previous. Thus proof that the model is suitable to the engineering practice.

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.

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