Particle Flow Code In 3 Dimensions Research Articles

Numerical Simulation on Combined Deformation of Tip-Loaded Cantilever Beam with Particle Flow Code

In order to calculate the combined deformations of an Euler-Bernoulli cantilever beam subjected to bending moment, twisting moment, transverse load and axial load, particle flow code in 3 dimensions (PFC3D) is used with parallel bonds model. The computed deformations, including transverse deflections, rotations about axis, maximum normal and shear stresses, were compared with the analytical beam-theory solution in terms of axial tension, axial compression and none axial load, respectively. Between computed results and analytical beam-theory solution, the error bands are greater than 99.7% at the beam tip, while the error of the transverse deflection of the whole beam is less than 0.6%. So, the PFC3D is able to precisely simulate the combined deformation of cantilever beam, and this work has special reference to engineering calculations and designs when PFC is applied to model the mechanical behaviors of continuum materials.

Simulation and Analysis on the Direct Shearing of Semi-Fixed Abrasive Tool

This paper firstly summarizes two-dimensional numerical simulation of semi-fixed abrasive tool (SFAT), then three-dimensional model of SFAT is established by PFC3D (Particle Flow Code in 3 Dimensions). In order to make the compression ratio simulation match to experimental one about SFAT, the mechanical parameters of model are adjusted. In the direct shearing simulation, the relation between the shear stress and the horizontal shear displacement under different parallel bond stiffness are obtained. By Comparative Analysis the numerical results and test experiments of the direct shearing, the three-dimensional model of SFAT is further proven rational.

Numerical simulation of the top coal caving process using the discrete element method

How to understand the top coal caving process and increase the top coal recovery ratio is one of the urgent problems to resolve for longwall top coal caving technology. This paper discusses a new theory and technology of top coal caving with vibration. The vibration device is mounted on the shield beam of the top coal caving support. The vibrator destroys the arch structure formed during the top coal caving process, which results in the smooth top coal caving process, and in this way the top coal recovery ratio is increased. The distinct element method (DEM) numerical software particle flow code in 2 dimensions (PFC2D) is used for the numerical simulation. It is proven that the vibration can easily destroy the arch structure which is formed during the top coal caving process. The parameters about when the arch structure would be formed during the top coal caving process have been obtained. The movement of the top coal caving process under the vibration condition makes a more stable layer uniform caving performance. The aim of the top coal caving with vibration technology, to increase the top coal recovery ratio and to lower the waste content rate, has been achieved.

3차원 입자 결합 모델에서 콘크리트의 일축압축실험 모사 적용성 연구

In an uniaxial compressive test of a concrete standard specimen (150300 mm) the crack initiation and extension with the stress increase are the major reason of the failure, which is similar to the breakage of the particle bonding in the simulation by using particle bonded model, especially particle flow code in 3 dimensions (PFC3D) developed by Itasca Consulting Group Inc. That is the main motive to study the possibility of an uniaxial compressive strength test simulation. It is important to investigate the relationship between the micro-parameters and the macro-properties because the 3-dimensional particle bonded model uses the spherical particles to analyze the physical phenomena. Contact bonded model used herein has eight micro-parameters and there are five macro-properties; Young`s modulus, Poisson`s ratio, uniaxial compressive strength and the crack initiation stress and the ratio concerning the crack propagation with the stress. To simulate the compressive test we made quantitative relationships between the micro-parameters and the macro-properties by using the fractional factorial design and various sensitivity analyses including regression analysis, which result in the good agreement with the previous studies. Also, the stress-stain curve and the crack distribution over the specimen given by PFC3D showed the mechanical behavior of the concrete standard specimen under the uniaxial compression. It is concluded that the particle bonded model can be a good tool for the analyzing the mechanical behavior of concrete under the uniaxial compressive load.