scholarly journals Three-Dimension Random Aggregate Generation of Numerical Concrete Model

2018 ◽  
Vol 206 ◽  
pp. 02009 ◽  
Author(s):  
Jianxin Ding ◽  
Qingzhou Yang
Keyword(s):  
Numerical Calculation ◽  
Numerical Model ◽  
Three Dimension ◽  
Aggregate Model ◽  
Convex Polyhedral ◽  
Aggregate Content ◽  
Spherical Aggregate ◽  
Random Aggregate ◽  
Concrete Model ◽  
Random Convex

The aggregate generation of concrete is one of the important problems in concrete mesoscopic mechanics. Firstly, the mesoscopic numerical model with spherical aggregates is obtained by the method of excluding the occupied space, and fully-graded concrete model of high aggregate content can be quickly generated. Then, based on the spherical aggregate model, the generation method of random convex polyhedral aggregates is proposed. Finally, a full-graded concrete model with spherical aggregates is shown in Case 1 and a cylindrical concrete model with random convex polyhedral aggregates is shown in Case 2. The result shows that the aggregates are equally distributed in the concrete models which can be used in the study of mesoscopic numerical calculation.

Application of Random Aggregate Model to the Problem of Concrete Penetration

2012 ◽  
Vol 446-449 ◽  
pp. 546-549
Author(s):  
Yi Zeng ◽  
Jun Lin Tao ◽  
Yong Yao ◽  
Xiao Ling Liu ◽  
Qian Hui Ren
Keyword(s):  
High Strain ◽  
Constitutive Relations ◽  
Large Strains ◽  
Two Dimensional ◽  
Penetration Test ◽  
Convex Polygons ◽  
Aggregate Model ◽  
Random Aggregate ◽  
Random Aggregate Model ◽  
Random Convex

Penetration of concrete targets was simulated based on self-compiled program generating two-dimensional random aggregate model. Random convex polygons were used to simulate the aggregate particles of concrete, HJC model to describe constitutive relations of the aggregates and mortar while concrete targets are subjected to large strains, high pressure and high strain rate. With this model, the Forrestal's penetration test was simulated by ls-dyna software. By comparing the calculated results with the test data, It is shown that random aggregate model can be applied to simulate the dynamic destruction problems of concrete-like materials.

Numerical calculation of crack width in prestressed concrete beams with bond-slip effect

2019 ◽  
Vol 15 (2) ◽  
pp. 523-536
Author(s):  
Jinliang Liu ◽  
Yanmin Jia ◽  
Guanhua Zhang ◽  
Jiawei Wang
Keyword(s):  
Numerical Calculation ◽  
Numerical Model ◽  
Prestressed Concrete ◽  
Calculation Method ◽  
Crack Width ◽  
Calculation Model ◽  
Content Type ◽  
Bond Slip ◽  
Stress Calculation ◽  
Bonding Performance

Purpose The calculation of the crack width is necessary for the design of prestressed concrete (PC) members. The purpose of this paper is to develop a numerical model based on the bond-slip theory to calculate the crack width in PC beams. Design/methodology/approach Stress calculation method for common reinforcement after beam crack has occurred depends on the difference in the bonding performance between prestressed reinforcement and common reinforcement. A numerical calculation model for determining the crack width in PC beams is developed based on the bond-slip theory, and verified using experimental data. The calculation values obtained by the proposed numerical model and code formulas are compared, and the applicability of the numerical model is evaluated. Findings The theoretical analysis and experimental results verified that the crack width of PC members calculated based on the bond-slip theory in this study is reasonable. Furthermore, the stress calculation method for the common reinforcement is verified. Compared with the model calculation results obtained in this study, the results obtained from code formulas are more conservative. Originality/value The numerical calculation model for crack width proposed in this study can be used by engineers as a reference for calculating the crack width in PC beams to ensure the durability of the PC member.

scholarly journals Image Analysis and Functional Data Clustering for Random Shape Aggregate Models

Mathematics ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1903
Author(s):  
Jonghyun Yun ◽  
Sanggoo Kang ◽  
Amin Darabnoush Tehrani ◽  
Suyun Ham
Keyword(s):  
Image Analysis ◽  
Mixture Model ◽  
Functional Data ◽  
Data Clustering ◽  
Learning Algorithm ◽  
Morphological Characteristics ◽  
Random Shape ◽  
Aggregate Model ◽  
Random Aggregate ◽  
Aggregate Morphology

This study presents a random shape aggregate model by establishing a functional mixture model for images of aggregate shapes. The mesoscale simulation to consider heterogeneous properties concrete is the highly cost- and time-effective method to predict the mechanical behavior of the concrete. Due to the significance of the design of the mesoscale concrete model, the shape of the aggregate is the most important parameter to obtain a reliable simulation result. We propose image analysis and functional data clustering for random shape aggregate models (IFAM). This novel technique learns the morphological characteristics of aggregates using images of real aggregates as inputs. IFAM provides random aggregates across a broad range of heterogeneous shapes using samples drawn from the estimated functional mixture model as outputs. Our learning algorithm is fully automated and allows flexible learning of the complex characteristics. Therefore, unlike similar studies, IFAM does not require users to perform time-consuming tuning on their model to provide realistic aggregate morphology. Using comparative studies, we demonstrate the random aggregate structures constructed by IFAM achieve close similarities to real aggregates in an inhomogeneous concrete medium. Thanks to our fully data-driven method, users can choose their own libraries of real aggregates for the training of the model and generate random aggregates with high similarities to the target libraries.

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.

Numerical Simulation on Damage and Failure of Recycled Aggregate Concrete with a Lattice Model

2009 ◽  
Vol 417-418 ◽  
pp. 689-692 ◽  
Author(s):  
Jian Zhuang Xiao ◽  
Qiong Liu ◽  
Vivian W.Y. Tam
Keyword(s):  
Lattice Model ◽  
Structural Damage ◽  
Fortran Program ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Model ◽  
Mixture Ratio ◽  
Aggregate Concrete ◽  
Damage And Failure ◽  
Random Aggregate

A random aggregate model of recycled aggregate concrete is developed in this paper on the base of a mixture ratio. Combining a lattice model with random aggregate of recycled aggregate concrete, lattice elements in the lattice model of recycled aggregate concrete can be classified into five types: (1) nature aggregate, (2) old hardened mortar, (3) new hardened mortar, (4) old interface transition zone (ITZ), and (5) new ITZ. The fundamental mechanical parameters of the lattice elements are chosen from the authors’ test as well as other references. A FORTRAN program of the lattice model is then written with basic theories of finite element method (FEM) for simulating the meso-structural damage of recycled aggregate concrete under uniaxial compression.

Improving Design of Muffler Based on Three-Dimension Numerical Calculation of Fluid and Sound Field

2011 ◽  
Vol 295-297 ◽  
pp. 2300-2303
Author(s):  
Hai Jun Zhao ◽  
Jia Dong Chang ◽  
Hong Jie Zhao
Keyword(s):  
Numerical Calculation ◽  
Environmental Pollution ◽  
Rotational Speed ◽  
Pressure Loss ◽  
Sound Field ◽  
Original Structure ◽  
Three Dimension ◽  
Vehicle Noise ◽  
Important Method ◽  
Aerodynamic Quality

Presence problem of exhaust muffler is anal sized, using three three-dimension numerical calculation of fluid and sound field improvement on original structure is performed, and improving results are certificated. It is shown that insert loss under every rotational speed all reach to the standard of 28dB（A）, and the noises of stationary end tube on the attention frequency band are all smaller than 5 dB（A） , and its pressure loss is decreased by about 32% than 7.6kPa of original structure muffler. So performance of the muffler is evidence increased, an important method is provided for decreasing whole vehicle noise, improving aerodynamic quality and reducing environmental pollution.

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.

3D Modeling of Complicated Geological Body in Numerical Software

2011 ◽  
Vol 255-260 ◽  
pp. 1895-1899
Author(s):  
Dong Ming Yu ◽  
Hai Lin Yao ◽  
Feng Guang Chen
Keyword(s):  
Numerical Calculation ◽  
Numerical Model ◽  
3D Modeling ◽  
Geotechnical Engineering ◽  
Modeling Method ◽  
Practical Significance ◽  
High Quality ◽  
Geological Body ◽  
Numerical Software ◽  
3D Numerical Model

This paper provides a simple and effective modeling method for complicated geological bodies in numerical software. By means of the most common tool software, the high quality 3d numerical model of the complicated geological body in the geotechnical engineering was built quickly and easily in the numerical software, ANSYS. Furthermore, this numerical model was reproduced in other numerical software, FLAC3D and ABAQUS. It is achieved that the 3d numerical model is shared among the numerical software, ANSYS, FLAC3D and ABAQUS and a basis is supplied for numerical calculation. The modeling method in this paper is of practical significance.

Sign in / Sign up

Export Citation Format

Share Document