The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Xiang Zhang - One of the best experts on this subject based on the ideXlab platform.
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An accurate elasto-plastic frictional Tangential Force-displacement model for granular-flow simulations: Displacement-driven formulation
Journal of Computational Physics, 2007Co-Authors: Xiang Zhang, Loc Vu-quocAbstract:We present in this paper the displacement-driven version of a Tangential Force-displacement (TFD) model that accounts for both elastic and plastic deformations together with interfacial friction occurring in collisions of spherical particles. This elasto-plastic frictional TFD model, with its Force-driven version presented in [L. Vu-Quoc, L. Lesburg, X. Zhang. An accurate Tangential Force-displacement model for granular-flow simulations: contacting spheres with plastic deformation, Force-driven formulation, Journal of Computational Physics 196(1) (2004) 298-326], is consistent with the elasto-plastic frictional normal Force-displacement (NFD) model presented in [L. Vu-Quoc, X. Zhang. An elasto-plastic contact Force-displacement model in the normal direction: displacement-driven version, Proceedings of the Royal Society of London, Series A 455 (1991) 4013-4044]. Both the NFD model and the present TFD model are based on the concept of additive decomposition of the radius of contact area into an elastic part and a plastic part. The effect of permanent indentation after impact is represented by a correction to the radius of curvature. The effect of material softening due to plastic flow is represented by a correction to the elastic moduli. The proposed TFD model is accurate, and is validated against nonlinear finite element analyses involving plastic flows in both the loading and unloading conditions. The proposed consistent displacement-driven, elasto-plastic NFD and TFD models are designed for implementation in computer codes using the discrete-element method (DEM) for granular-flow simulations. The model is shown to be accurate and is validated against nonlinear elasto-plastic finite-element analysis.
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An accurate Tangential Force-displacement model for granular-flow simulations: contacting spheres with plastic deformation, Force-driven formulation
Journal of Computational Physics, 2004Co-Authors: Loc Vu-quoc, L. Lesburg, Xiang ZhangAbstract:An elasto-plastic frictional Tangential Force-displacement (TFD) model for spheres in contact for accurate and efficient granular-flow simulations is presented in this paper: the present TFD is consistent with the elasto-plastic normal Force displacement (NFD) model presented in [ASME Journal of Applied Mechanics 67 (2) (2000) 363: Proceedings of the Royal Society of London, Series A 455 (1991) (1999) 4013]. The proposed elasto-plastic frictional TFD model is accurate, and is validated against non-linear finite-element analyses involving plastic flows under both loading and unloading conditions. The novelty of the present TFD model lies in (i) the additive decomposition of the elasto-plastic contact area radius into an elastic part and a plastic part, (ii) the correction of the particles' radii at the contact point, and (iii) the correction of the particles' elastic moduli. The correction of the contact-area radius represents an effect of plastic deformation in colliding particles; the correction of the radius of curvature represents a permanent indentation after impact; the correction of the elastic moduli represents a softening of the material due to plastic flow. The construction of both the present elasto-plastic frictional TFD model and its consistent companion, the elasto-plastic NFD model, parallels the formalism of the continuum theory of elasto-plasticity. Both NFD and TFD models form a coherent set of Force-displacement (FD) models not available hitherto for granular-flow simulations, and are consistent with the Hertz, Cattaneo, Mindlin, Deresiewicz contact mechanics theory. Together. these FD models will allow for efficient simulations of granular flows (or granular gases) involving a large number of particles.
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Simulation of chute flow of soybeans using an improved Tangential Force-displacement model
Mechanics of Materials, 2000Co-Authors: Xiang Zhang, Loc Vu-quocAbstract:Abstract Discrete element method (DEM) is widely used for the computer simulations of the motion behavior of granular materials. We use the DEM simulation with the improved Tangential Force–displacement model proposed by Vu-Quoc, L., Zhang, X., (1999) [Mechanics of Materials 31, 235–265] to simulate soybeans flowing down an inclined chute with a bumpy bottom. In the normal direction at the contact point between two particles, the bilinear Force–displacement model proposed by Walton, O.R., Braun, R.L., 1986 [Journal of Rheology 30 (5), 949–980] is employed. Soybeans (non-spherical particles) are represented by clusters of spheres to simplify the contact detection. The simulation results such as velocity profiles are presented, and compared with corresponding experimental results. In addition, Force statistics of the soybean flow that cannot be obtained using conventional experiments are extracted from simulation results and presented.
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an accurate and efficient Tangential Force displacement model for elastic frictional contact in particle flow simulations
Mechanics of Materials, 1999Co-Authors: L Vuquoc, Xiang ZhangAbstract:Abstract An improved Tangential Force–displacement (TFD) model for 3-D discrete element simulations of dry particle systems is proposed in this paper. This model is based on the Mindlin and Deresiewicz (1953) theory for elastic frictional contact. Comparisons of the Force–displacement (FD) behavior of this model with the Mindlin and Deresiewicz (1953) theory and the Walton and Braun (1986) TFD model are presented. Finite element method validation was also carried out for the proposed TFD model. We implemented this model in a particle simulation code. To validate the computer code, simulations were carried out for a benchmark test of 100 hard spherical particles colliding with a rigid planar surface. We also present the results obtained from the simulation of ellipsoidal particles flowing down a chute, with a bumpy bottom, using a parallelepiped having four periodic lateral boundaries as the simulation domain. Results such as the development of the granular flow velocity, contact Force statistics, etc., are presented and discussed.
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An accurate and efficient Tangential Force–displacement model for elastic frictional contact in particle-flow simulations
Mechanics of Materials, 1999Co-Authors: Loc Vu-quoc, Xiang ZhangAbstract:Abstract An improved Tangential Force–displacement (TFD) model for 3-D discrete element simulations of dry particle systems is proposed in this paper. This model is based on the Mindlin and Deresiewicz (1953) theory for elastic frictional contact. Comparisons of the Force–displacement (FD) behavior of this model with the Mindlin and Deresiewicz (1953) theory and the Walton and Braun (1986) TFD model are presented. Finite element method validation was also carried out for the proposed TFD model. We implemented this model in a particle simulation code. To validate the computer code, simulations were carried out for a benchmark test of 100 hard spherical particles colliding with a rigid planar surface. We also present the results obtained from the simulation of ellipsoidal particles flowing down a chute, with a bumpy bottom, using a parallelepiped having four periodic lateral boundaries as the simulation domain. Results such as the development of the granular flow velocity, contact Force statistics, etc., are presented and discussed.
Loc Vu-quoc - One of the best experts on this subject based on the ideXlab platform.
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An accurate elasto-plastic frictional Tangential Force-displacement model for granular-flow simulations: Displacement-driven formulation
Journal of Computational Physics, 2007Co-Authors: Xiang Zhang, Loc Vu-quocAbstract:We present in this paper the displacement-driven version of a Tangential Force-displacement (TFD) model that accounts for both elastic and plastic deformations together with interfacial friction occurring in collisions of spherical particles. This elasto-plastic frictional TFD model, with its Force-driven version presented in [L. Vu-Quoc, L. Lesburg, X. Zhang. An accurate Tangential Force-displacement model for granular-flow simulations: contacting spheres with plastic deformation, Force-driven formulation, Journal of Computational Physics 196(1) (2004) 298-326], is consistent with the elasto-plastic frictional normal Force-displacement (NFD) model presented in [L. Vu-Quoc, X. Zhang. An elasto-plastic contact Force-displacement model in the normal direction: displacement-driven version, Proceedings of the Royal Society of London, Series A 455 (1991) 4013-4044]. Both the NFD model and the present TFD model are based on the concept of additive decomposition of the radius of contact area into an elastic part and a plastic part. The effect of permanent indentation after impact is represented by a correction to the radius of curvature. The effect of material softening due to plastic flow is represented by a correction to the elastic moduli. The proposed TFD model is accurate, and is validated against nonlinear finite element analyses involving plastic flows in both the loading and unloading conditions. The proposed consistent displacement-driven, elasto-plastic NFD and TFD models are designed for implementation in computer codes using the discrete-element method (DEM) for granular-flow simulations. The model is shown to be accurate and is validated against nonlinear elasto-plastic finite-element analysis.
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An accurate Tangential Force-displacement model for granular-flow simulations: contacting spheres with plastic deformation, Force-driven formulation
Journal of Computational Physics, 2004Co-Authors: Loc Vu-quoc, L. Lesburg, Xiang ZhangAbstract:An elasto-plastic frictional Tangential Force-displacement (TFD) model for spheres in contact for accurate and efficient granular-flow simulations is presented in this paper: the present TFD is consistent with the elasto-plastic normal Force displacement (NFD) model presented in [ASME Journal of Applied Mechanics 67 (2) (2000) 363: Proceedings of the Royal Society of London, Series A 455 (1991) (1999) 4013]. The proposed elasto-plastic frictional TFD model is accurate, and is validated against non-linear finite-element analyses involving plastic flows under both loading and unloading conditions. The novelty of the present TFD model lies in (i) the additive decomposition of the elasto-plastic contact area radius into an elastic part and a plastic part, (ii) the correction of the particles' radii at the contact point, and (iii) the correction of the particles' elastic moduli. The correction of the contact-area radius represents an effect of plastic deformation in colliding particles; the correction of the radius of curvature represents a permanent indentation after impact; the correction of the elastic moduli represents a softening of the material due to plastic flow. The construction of both the present elasto-plastic frictional TFD model and its consistent companion, the elasto-plastic NFD model, parallels the formalism of the continuum theory of elasto-plasticity. Both NFD and TFD models form a coherent set of Force-displacement (FD) models not available hitherto for granular-flow simulations, and are consistent with the Hertz, Cattaneo, Mindlin, Deresiewicz contact mechanics theory. Together. these FD models will allow for efficient simulations of granular flows (or granular gases) involving a large number of particles.
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Simulation of chute flow of soybeans using an improved Tangential Force-displacement model
Mechanics of Materials, 2000Co-Authors: Xiang Zhang, Loc Vu-quocAbstract:Abstract Discrete element method (DEM) is widely used for the computer simulations of the motion behavior of granular materials. We use the DEM simulation with the improved Tangential Force–displacement model proposed by Vu-Quoc, L., Zhang, X., (1999) [Mechanics of Materials 31, 235–265] to simulate soybeans flowing down an inclined chute with a bumpy bottom. In the normal direction at the contact point between two particles, the bilinear Force–displacement model proposed by Walton, O.R., Braun, R.L., 1986 [Journal of Rheology 30 (5), 949–980] is employed. Soybeans (non-spherical particles) are represented by clusters of spheres to simplify the contact detection. The simulation results such as velocity profiles are presented, and compared with corresponding experimental results. In addition, Force statistics of the soybean flow that cannot be obtained using conventional experiments are extracted from simulation results and presented.
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An accurate and efficient Tangential Force–displacement model for elastic frictional contact in particle-flow simulations
Mechanics of Materials, 1999Co-Authors: Loc Vu-quoc, Xiang ZhangAbstract:Abstract An improved Tangential Force–displacement (TFD) model for 3-D discrete element simulations of dry particle systems is proposed in this paper. This model is based on the Mindlin and Deresiewicz (1953) theory for elastic frictional contact. Comparisons of the Force–displacement (FD) behavior of this model with the Mindlin and Deresiewicz (1953) theory and the Walton and Braun (1986) TFD model are presented. Finite element method validation was also carried out for the proposed TFD model. We implemented this model in a particle simulation code. To validate the computer code, simulations were carried out for a benchmark test of 100 hard spherical particles colliding with a rigid planar surface. We also present the results obtained from the simulation of ellipsoidal particles flowing down a chute, with a bumpy bottom, using a parallelepiped having four periodic lateral boundaries as the simulation domain. Results such as the development of the granular flow velocity, contact Force statistics, etc., are presented and discussed.
Hiroyuki Kajimoto - One of the best experts on this subject based on the ideXlab platform.
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Tangential Force input for touch panels using bezel aligned elastic pillars and a transparent sheet
User Interface Software and Technology, 2014Co-Authors: Yuriko Nakai, Shinya Kudo, Ryuta Okazaki, Hiroyuki KajimotoAbstract:This research aims to enable Tangential Force input for touch panels by measuring the Tangential Force. The system is composed of a plastic sheet on a touch panel, urethane pillars on the panel that are aligned at the four corners of the bezel, and a case on top of the pillars. When the sheet moves with a finger, the pillars deform so that a Tangential Force can be obtained by measuring the movement of the finger. We evaluated the method and found that the system showed realistic Force sensing accuracy in any direction. This input method will enable development of new applications for touch panels such as using any part of the touch panel surface as joysticks, or modeling virtual objects by deforming them with the fingers.
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detection of Tangential Force for a touch panel using shear deformation of the gel
Human Factors in Computing Systems, 2014Co-Authors: Yuriko Nakai, Shinya Kudo, Ryuta Okazaki, Hiroyuki Kajimoto, Hidenori KuribayashiAbstract:Many capacitive touch panels detect the position and contact area of the user finger, and can estimate the vertical Force from the change in the contact area. However, they cannot detect and measure the Tangential Force. This research aims to enable the measurement of Tangential Force using a gel layer, which deforms when a Tangential Force is applied. By measuring the finger motion of the user, we can estimate Tangential Force from the gel spring ratio. Using this input method, any part of the touch panel surface becomes a joystick, or virtual objects can be modeled by deforming them with the fingers.
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CHI Extended Abstracts - Detection of Tangential Force for a touch panel using shear deformation of the gel
CHI '14 Extended Abstracts on Human Factors in Computing Systems, 2014Co-Authors: Yuriko Nakai, Shinya Kudo, Ryuta Okazaki, Hiroyuki Kajimoto, Hidenori KuribayashiAbstract:Many capacitive touch panels detect the position and contact area of the user finger, and can estimate the vertical Force from the change in the contact area. However, they cannot detect and measure the Tangential Force. This research aims to enable the measurement of Tangential Force using a gel layer, which deforms when a Tangential Force is applied. By measuring the finger motion of the user, we can estimate Tangential Force from the gel spring ratio. Using this input method, any part of the touch panel surface becomes a joystick, or virtual objects can be modeled by deforming them with the fingers.
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UIST (Adjunct Volume) - Tangential Force input for touch panels using bezel-aligned elastic pillars and a transparent sheet
Proceedings of the adjunct publication of the 27th annual ACM symposium on User interface software and technology - UIST'14 Adjunct, 2014Co-Authors: Yuriko Nakai, Shinya Kudo, Ryuta Okazaki, Hiroyuki KajimotoAbstract:This research aims to enable Tangential Force input for touch panels by measuring the Tangential Force. The system is composed of a plastic sheet on a touch panel, urethane pillars on the panel that are aligned at the four corners of the bezel, and a case on top of the pillars. When the sheet moves with a finger, the pillars deform so that a Tangential Force can be obtained by measuring the movement of the finger. We evaluated the method and found that the system showed realistic Force sensing accuracy in any direction. This input method will enable development of new applications for touch panels such as using any part of the touch panel surface as joysticks, or modeling virtual objects by deforming them with the fingers.
C.k. Umesh - One of the best experts on this subject based on the ideXlab platform.
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Analysis of Feed Force, Tangential Force and Surface Roughness in Turning of En-353 Steel with Un-Coated Ceramic Cutting Tool using Taguchi Method
International Journal for Scientific Research and Development, 2015Co-Authors: Biradar Shivanand Rajendra, B. Dadapeer, C.k. UmeshAbstract:The aim of the present paper is to investigate the effects of process parameters (cutting speed, feed rate and depth of cut) on performance characteristics (feed Force, Tangential Force and surface roughness) in turning of EN-353 steel using uncoated ceramic cutting tool inserts. Experiments are designed and conducted based on Taguchi L9 orthogonal array carried out under dry cutting conditions for feed Force, Tangential Force and surface roughness. The responses such as feed Force, Tangential Force and surface roughness were recorded for each experiment. The depth of cut was identified as the most influential process parameters in the responses of both feed Force and Tangential Force. The feed rate was identified as the most influential process parameter on the surface roughness.
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Analysis and Prediction of feed Force, Tangential Force, surface roughness and flank wear in Turning with uncoated carbide cutting tool using both Taguchi and Grey based taguchi method
2015Co-Authors: R. Manjunatha, C.k. UmeshAbstract:The aim of the present study is to investigate the effects of process parameters (cutting speed, feed rate and depth of cut) on performance characteristics (Tangential Force, feed Force, surface roughness and flank wear ) in turning of EN-19 steel with uncoated carbide cutting tool. Experiments are designed and conducted based on Taguchi's L27 orthogonal array carried out under dry cutting conditions for Tangential Force, feed Force and surface roughness, whereas for the flank wear the experiments are conducted as per L9 orthogonal array. The responses are feed Force, Tangential Force, surface roughness and flank wear were recorded for each experiment The depth of cut was identified as the most influential process parameters in the responses of both Tangential Force and feed Force. The feed rate was identified as the most influential process parameter on the surface roughness, while the cutting speed has a significant contribution for flank wear. Grey relational analysis is used to optimize the multi-performance characteristics to minimize the Tangential Force and surface roughness. The feed rate was identified as the most influential process parameter in the responses of both Tangential Force and surface roughness
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Machining Studies of EN-353 Steel Using Taguchi Technique by Turning Operation
2015Co-Authors: C.k. Umesh, B K MuralidharaAbstract:This paper presents an optimization method of the cutting parameters like cutting speed, feed rate and depth of cut in dry turning of EN-353 steel in order to study the performance of coated and uncoated ceramic cutting tool inserts. Experiments are designed and conducted based on Taguchi's L9 orthogonal array carried out under dry cutting conditions. The Force measured are feed Force, Tangential Force and to achieve minimum flank wear measured by optical tool wear microscope. The depth of cut was identified as the most influential process parameters in the responses of both feed Force and Tangential Force. The cutting speed has a significant contribution for flank wear. Finally, the feed rate was identified as the most influential process parameter in the responses of both feed Force and Tangential Force. Keywords—Feed Force; Tangential Force; flank
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Optimization of feed Force, Tangential Force and surface roughness by using grey based Taguchi method
2014Co-Authors: R. Manjunatha, C.k. UmeshAbstract:This study investigated the optimization of turning process parameters such as cutting speed, feed rate and depth of cut on EN-19 material using the Grey Relational Analysis (GRA) method. Twenty seven experimental runs based on an orthogonal array of Taguchi method were performed. The feed Force (F X), Tangential Force (FY) and surface roughness (R a) were selected as the quality targets. An optimal parameter combination of the turning operation was obtained using GRA. By analyzing the grey relational grade matrix, the degree of influenced for each controllable process factor onto individual quality targets can be found. The depth of cut is identified to be the most influence on feed Force and Tangential Force, and feed rate is the most influential factor to the surface roughness. Additionally, the analysis of variance (ANOVA) was also applied to identify the most significant factor; the depth of cut is the most significant controlled factor for the turning operation according to the weighted sum grade of the feed Force, Tangential Force and surface roughness.
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Optimization of Tangential Force, Feed Force and Surface Roughness Using Taguchi Technique in Turning Operation
Procedia Materials Science, 2014Co-Authors: R. Manjunatha, C.k. UmeshAbstract:Abstract The objective of this paper is to obtain optimal turning process parameters (cutting speed, feed rate and depth of cut) resulting in an optimal value of feed Force, Tangential Force and surface roughness for machining EN-19 steel with an coated carbide tool insert. The effects of the process parameters on the various responses have been arrived at using Taguchi's design of experiments approach. The results indicate that the selected process parameters significantly affect the mean and variance of feed Force, Tangential Force and surface roughness. The contributions of parameters from the ANOVA table for measured feed Force, the depth of cut (78.3%) has a major contribution than that of feed rate (8.0%) and cutting speed (5.1%). Similarly for a measured Tangential Force (Fy) the depth of cut (70.6%) has a major contribution than that of feed rate (24.4%) and cutting speed (1.6%). In case of measured surface roughness (Ra), the feed rate (67.8%) has a major contribution, the cutting speed (14.4%) and depth of cut (12.5%). The predicted optimum feed Force, Tangential Force and the surface roughness are 124 N, 187 N, and 2.36 μm respectively are very much near the experimentally obtained values.
Yuriko Nakai - One of the best experts on this subject based on the ideXlab platform.
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Tangential Force input for touch panels using bezel aligned elastic pillars and a transparent sheet
User Interface Software and Technology, 2014Co-Authors: Yuriko Nakai, Shinya Kudo, Ryuta Okazaki, Hiroyuki KajimotoAbstract:This research aims to enable Tangential Force input for touch panels by measuring the Tangential Force. The system is composed of a plastic sheet on a touch panel, urethane pillars on the panel that are aligned at the four corners of the bezel, and a case on top of the pillars. When the sheet moves with a finger, the pillars deform so that a Tangential Force can be obtained by measuring the movement of the finger. We evaluated the method and found that the system showed realistic Force sensing accuracy in any direction. This input method will enable development of new applications for touch panels such as using any part of the touch panel surface as joysticks, or modeling virtual objects by deforming them with the fingers.
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detection of Tangential Force for a touch panel using shear deformation of the gel
Human Factors in Computing Systems, 2014Co-Authors: Yuriko Nakai, Shinya Kudo, Ryuta Okazaki, Hiroyuki Kajimoto, Hidenori KuribayashiAbstract:Many capacitive touch panels detect the position and contact area of the user finger, and can estimate the vertical Force from the change in the contact area. However, they cannot detect and measure the Tangential Force. This research aims to enable the measurement of Tangential Force using a gel layer, which deforms when a Tangential Force is applied. By measuring the finger motion of the user, we can estimate Tangential Force from the gel spring ratio. Using this input method, any part of the touch panel surface becomes a joystick, or virtual objects can be modeled by deforming them with the fingers.
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CHI Extended Abstracts - Detection of Tangential Force for a touch panel using shear deformation of the gel
CHI '14 Extended Abstracts on Human Factors in Computing Systems, 2014Co-Authors: Yuriko Nakai, Shinya Kudo, Ryuta Okazaki, Hiroyuki Kajimoto, Hidenori KuribayashiAbstract:Many capacitive touch panels detect the position and contact area of the user finger, and can estimate the vertical Force from the change in the contact area. However, they cannot detect and measure the Tangential Force. This research aims to enable the measurement of Tangential Force using a gel layer, which deforms when a Tangential Force is applied. By measuring the finger motion of the user, we can estimate Tangential Force from the gel spring ratio. Using this input method, any part of the touch panel surface becomes a joystick, or virtual objects can be modeled by deforming them with the fingers.
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UIST (Adjunct Volume) - Tangential Force input for touch panels using bezel-aligned elastic pillars and a transparent sheet
Proceedings of the adjunct publication of the 27th annual ACM symposium on User interface software and technology - UIST'14 Adjunct, 2014Co-Authors: Yuriko Nakai, Shinya Kudo, Ryuta Okazaki, Hiroyuki KajimotoAbstract:This research aims to enable Tangential Force input for touch panels by measuring the Tangential Force. The system is composed of a plastic sheet on a touch panel, urethane pillars on the panel that are aligned at the four corners of the bezel, and a case on top of the pillars. When the sheet moves with a finger, the pillars deform so that a Tangential Force can be obtained by measuring the movement of the finger. We evaluated the method and found that the system showed realistic Force sensing accuracy in any direction. This input method will enable development of new applications for touch panels such as using any part of the touch panel surface as joysticks, or modeling virtual objects by deforming them with the fingers.
