Author
Yoshiyuki Shimizu
Bio: Yoshiyuki Shimizu is an academic researcher from Tokai University. The author has contributed to research in topics: Discrete element method & Micromechanics. The author has an hindex of 5, co-authored 17 publications receiving 177 citations.
Papers
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TL;DR: In this article, a numerical analysis using the 3D distinct element method (DEM) is conducted in order to examine the performance of screw conveyors, in particular, the simulation of horizontal and vertical types.
Abstract: A numerical analysis using the 3D distinct element method (DEM) is conducted in order to examine the performance of screw conveyors. In particular, the simulation of horizontal and vertical types is studied. The results are compared with previous work and empirical equations. As a result, it is determined that this method is sufficiently well developed and useful to analyze the performance of screw conveyors.
97 citations
TL;DR: Shimizu et al. as discussed by the authors proposed a particle-thermal-fluid coupling scheme with a mixed Lagrangian-Eulerian approach, which solves the continuity, Navier-Stokes (N-S) and thermal energy equations numerically in Eulerian Cartesian coordinates, then derives pressure, velocity vectors and temperature for each fixed cell by considering particle existence.
50 citations
TL;DR: In this paper, a microscopic numerical model of fluid flow through granular materials using the discrete element method is developed to take account of the effect of particle movement, where the calculated fluid pressure is applied to particles involved in the void space as a body force proportional to the occupied area in the space.
Abstract: A microscopic numerical model of fluid flow through granular materials using the discrete-element method is developed to take account of the effect of particle movement. The scheme solves for fluid pressure in void spaces surrounded by the particle elements used in the discrete-element method to consider the compressibility of fluid during particle movement and diffusion, that is flow across void spaces in a one-dimensional form of Darcy's law. The calculated fluid pressure is applied to particles involved in the void space as a body force proportional to the occupied area in the space. This microscopic two-way coupling method enables the analysis of the microscopic mechanical characteristics of granular materials associated with fluid, as many problems in geotechnics involve such interactions between particles and a pore fluid. The approach can be applied in situations with undrained dynamic loading inducing excess pore water pressure and subsequent liquefaction. The paper first describes the formulation...
14 citations
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11 Feb 2009
13 citations
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01 Jan 2015
TL;DR: Palavras-chave et al. as mentioned in this paper applied three criteria for delineating zones for soil compaction management: soil layer where first appear values of soil penetration resistance considered critical for sugarcane growth; cone index for 0-40 cm layer, and depth of occurrence of maximum soil penetration resist.
Abstract: A B S T R A C T Soil compaction influences all stages of crop growth, but in many low yield sugarcane fields critical levels and effects of soil compaction are ignored. Therefore, identifying localization and intensity of compaction are very relevant for descompactation of soil. In this context, this study aimed to apply three criteria for delineating zones for soil compaction management: soil layer where first appear values of soil penetration resistance considered critical for sugarcane growth; cone index for 0-40 cm layer, and depth of occurrence of maximum soil penetration resistance. Sampling was carried out in a grid with 113 points spaced at 100 m, georeferenced by means of a Global Positioning System receiver. Soil penetration resistance in eight layers of 5 cm depth, cone index and depth of occurrence of maximum penetration resistance were determined from data gathered by an automatic measuring penetrometer. Estimative of non-sampled values were obtained by means of kriging interpolation, which allowed drawing of contour maps and the definition of four regions in the field for site specific subsoiling . Palavras-chave: Saccharum ssp. resistencia do solo a penetracao geoestatistica penetrometro
412 citations
TL;DR: In this article, the authors provide a general overview of the application of computational techniques to the science of comminution, including simulation of fracture, breakage, crushing, milling and equipment wear.
257 citations
TL;DR: Current DEM models for several common pharmaceutical processes including material transport and storage, blending, granulation, milling, compression, and film coating are reviewed.
211 citations
TL;DR: In this paper, the Discrete Element Method (DEM) is applied to simulate a single pitch screw conveyor with periodic boundary conditions to predict the performance of screw conveyors in terms of variations of particle speeds, mass flow rate, energy dissipation and power consumption, due to changes in the operating conditions.
179 citations
TL;DR: In this article, the dynamic modulus of asphalt mixture using both two-dimensional and three-dimensional discrete element method (DEM) generated from the X-ray computed tomography (X-ray CT) images was analyzed.
Abstract: The objective of this study is to predict the dynamic modulus of asphalt mixture using both two-dimensional (2D) and three-dimensional (3D) Distinct Element Method (DEM) generated from the X-ray computed tomography (X-ray CT) images. The 3D internal microstructure of the asphalt mixtures (i.e., spatial distribution of aggregate, sand mastic and air voids) was obtained using the X-ray CT. The X-ray CT images provided exact locations of aggregate, sand mastic and air voids to develop 2D and 3D models. An experimental program was developed with a uniaxial compression test to measure the dynamic modulus of sand mastic and asphalt mixtures at different temperatures and loading frequencies. In the DEM simulation, the mastic dynamic modulus and aggregate elastic modulus were used as input parameters to predict the asphalt mixture dynamic modulus. Three replicates of a 3D DEM and six replicates of a 2D DEM were used in the simulation. The strain response of the asphalt concrete under a compressive load was monitored, and the dynamic modulus was computed. The moduli of the 3D DEM and 2D DEM were then compared with both the experimental measurements results. It was revealed that the 3D discrete element models successfully predicted the asphalt mixture dynamic modulus over a range of temperatures and loading frequencies. It was found that 2D discrete element models under predicted the asphalt mixture dynamic modulus.
165 citations