The Use of ADINA Software to Simulate Thixocasting Processes

2006 ◽  
Vol 116-117 ◽  
pp. 626-629 ◽  
Author(s):  
Krzysztof P. Sołek ◽  
Zbigniew Mitura ◽  
Roman Kuziak ◽  
Plato Kapranos
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Computer Simulations ◽  
Liquid State ◽  
Physical Simulation ◽  
Light Metal ◽  
Model Parameters ◽  
Physical Simulations ◽  
Solid Liquid

The main purpose of work was to develop a methodology of physical and numerical simulation of the thixocasting processes. For the purpose of the studies an experiment was conducted using a GLEEBLE 3800 simulator. In this work, the GLEEBLE 3800 system was adapted for physical simulation of the processes of light metal alloy forming in the solid-liquid state. The physical simulations of thixoforming processes and characterization of thixotropic materials were supported by computer simulations using ADINA software. The numerical model of thixoforming processes was developed in order to estimate values of the rheological model parameters.

scholarly journals The Lituya Bay landslide-generated mega-tsunami. Numerical simulation and sensitivity analysis

2018 ◽  
Author(s):  
José Manuel González-Vida ◽  
Jorge Macías ◽  
Manuel Jesús Castro ◽  
Carlos Sánchez-Linares ◽  
Marc de la Asunción ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Sensitivity Analysis ◽  
Numerical Model ◽  
Shallow Water ◽  
Extreme Event ◽  
Fluid Model ◽  
Model Parameters ◽  
Water Type ◽  
Bathymetric Data ◽  
Run Up

Abstract. The 1958 Lituya Bay landslide-generated mega-tsunami is simulated using the Landslide-HySEA model, a recently developed finite volume Savage-Hutter Shallow Water coupled numerical model. Two factors are crucial if the main objective of the numerical simulation is to reproduce the maximal run-up, with an accurate simulation of the inundated area and a precise re-creation of the known trimline of the 1958 mega-tsunami of Lituya Bay. First, the accurate reconstruction of the initial slide. Then, the choice of a suitable coupled landslide-fluid model able to reproduce how the energy released by the landslide is transmitted to the water and then propagated. Given the numerical model, the choice of parameters appears to be a point of major importance, this leads us to perform a sensitivity analysis. Based on public domain topo-bathymetric data, and on information extracted from the work of Miller (1960), an approximation of Gilbert Inlet topo-bathymetry was set up and used for the numerical simulation of the mega-event. Once optimal model parameters were set, comparisons with observational data were performed in order to validate the numerical results. In the present work, we demonstrate that a shallow water type of model is able to accurately reproduce such an extreme event as the Lituya Bay mega-tsunami. The resulting numerical simulation is one of the first successful attempts (if not the first) at numerically reproducing in detail the main features of this event in a realistic 3D basin geometry, where no smoothing or other stabilizing factors in the bathymetric data are applied.

scholarly journals A tool wear condition monitoring approach for end milling based on numerical simulation

2021 ◽  
Vol 23 (2) ◽  
pp. 371-380
Author(s):  
Qinsong Zhu ◽  
Weifang Sun ◽  
Yuqing Zhou ◽  
Chen Gao
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Tool Wear ◽  
Condition Monitoring ◽  
End Milling ◽  
Orthogonal Experiment ◽  
Research Area ◽  
Model Parameters ◽  
Evaluation Indexes ◽  
Important Research Area

As an important research area of modern manufacturing, tool condition monitoring (TCM) has attracted much attention, especially artificial intelligence (AI)- based TCM method. However, the training samples obtained in practical experiments have the problem of sample missing and sample insufficiency. A numerical simulation- based TCM method is proposed to solve the above problem. First, a numerical model based on Johnson-Cook model is established, and the model parameters are optimized through orthogonal experiment technology, in which the KL divergence and cosine similarity are used as the evaluation indexes. Second, samples under various tool wear categories are obtained by the optimized numerical model above to provide missing samples not present in the practical experiments and expand sample size. The effectiveness of the proposed method is verified by its application in end milling TCM experiments. The results indicate the classification accuracies of four classifiers (SVM, RF, DT, and GRNN) can be improved significantly by the proposed TCM method.

Evaluation of the characterization of acoustic emission of brittle rocks from the experiment to numerical simulation

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Fengchang Bu ◽  
Lei Xue ◽  
Mengyang Zhai ◽  
Xiaolin Huang ◽  
Jinyu Dong ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Acoustic Emission ◽  
Numerical Model ◽  
Particle Velocity ◽  
Moment Tensor ◽  
Failure Process ◽  
Experimental Result ◽  
Tensor Model ◽  
Brittle Rocks

AbstractAcoustic emission (AE) characterization is an effective technique to indirectly capture the failure process of quasi brittle rock. In previous studies, both experiments and numerical simulations were adopted to investigate the AE characteristics of rocks. However, as the most popular numerical model, the moment tensor model (MTM) cannot be constrained by the experimental result because there is a gap between MTM and experiments in principle, signal processing and energy analysis. In this paper, we developed a particle-velocity-based model (PVBM) that enabled direct monitoring and analysis of the particle velocity in the numerical model and had good robustness. The PVBM imitated the actual experiment and could fill in gaps between the experiment and MTM. AE experiments of marine shale under uniaxial compression were carried out, and the results were simulated by MTM. In general, the variation trend of the experimental result could be presented by MTM. Nevertheless, the magnitudes of AE parameters by MTM presented notable differences of more than several orders of magnitude compared with those by the experiment. We sequentially used PVBM as a proxy to analyse these discrepancies and systematically evaluate the AE characterization of rocks from the experiment to numerical simulation, considering the influence of wave reflection, energy geometrical diffusion, viscous attenuation, particle size and progressive deterioration of rock material. The combination of MTM and PVBM could reasonably and accurately acquire AE characteristics of the actual AE experiment of rocks by making full use of their respective advantages.

scholarly journals The Lituya Bay landslide-generated mega-tsunami – numerical simulation and sensitivity analysis

2019 ◽  
Vol 19 (2) ◽  
pp. 369-388 ◽  
Author(s):  
José Manuel González-Vida ◽  
Jorge Macías ◽  
Manuel Jesús Castro ◽  
Carlos Sánchez-Linares ◽  
Marc de la Asunción ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Sensitivity Analysis ◽  
Numerical Model ◽  
Shallow Water ◽  
Extreme Event ◽  
Fluid Model ◽  
Model Parameters ◽  
Water Type ◽  
Bathymetric Data ◽  
Run Up

Abstract. The 1958 Lituya Bay landslide-generated mega-tsunami is simulated using the Landslide-HySEA model, a recently developed finite-volume Savage–Hutter shallow water coupled numerical model. Two factors are crucial if the main objective of the numerical simulation is to reproduce the maximal run-up with an accurate simulation of the inundated area and a precise recreation of the known trimline of the 1958 mega-tsunami of Lituya Bay: first, the accurate reconstruction of the initial slide and then the choice of a suitable coupled landslide–fluid model able to reproduce how the energy released by the landslide is transmitted to the water and then propagated. Given the numerical model, the choice of parameters appears to be a point of major importance, which leads us to perform a sensitivity analysis. Based on public domain topo-bathymetric data, and on information extracted from the work of Miller (1960), an approximation of Gilbert Inlet topo-bathymetry was set up and used for the numerical simulation of the mega-event. Once optimal model parameters were set, comparisons with observational data were performed in order to validate the numerical results. In the present work, we demonstrate that a shallow water type of model is able to accurately reproduce such an extreme event as the Lituya Bay mega-tsunami. The resulting numerical simulation is one of the first successful attempts (if not the first) at numerically reproducing, in detail, the main features of this event in a realistic 3-D basin geometry, where no smoothing or other stabilizing factors in the bathymetric data are applied.

scholarly journals Blowing and drifting snow in Alpine terrain: numerical simulation and related field measurements

1998 ◽  
Vol 26 ◽  
pp. 174-178 ◽  
Author(s):  
Peter Gauer
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Three Dimensional ◽  
Field Measurements ◽  
Blowing Snow ◽  
Related Field ◽  
Drifting Snow ◽  
Physically Based ◽  
Snow Transport

A physically based numerical model of drifting and blowing snow in three-dimensional terrain is developed. The model includes snow transport by saltation and suspension. As an example, a numerical simulation for an Alpine ridge is presented and compared with field measurements.

scholarly journals Rheological Characterization of a Concentrated Phosphate Slurry

Fluids ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 178
Author(s):  
Souhail Maazioui ◽  
Abderrahim Maazouz ◽  
Fayssal Benkhaldoun ◽  
Driss Ouazar ◽  
Khalid Lamnawar
Keyword(s):  
Flow Behavior ◽  
Continuous Phase ◽  
Raw Material ◽  
Rheological Characterization ◽  
Phosphate Ore ◽  
Insoluble Particles ◽  
Experimental Protocols ◽  
Solid Liquid

Phosphate ore slurry is a suspension of insoluble particles of phosphate rock, the primary raw material for fertilizer and phosphoric acid, in a continuous phase of water. This suspension has a non-Newtonian flow behavior and exhibits yield stress as the shear rate tends toward zero. The suspended particles in the present study were assumed to be noncolloidal. Various grades and phosphate ore concentrations were chosen for this rheological investigation. We created some experimental protocols to determine the main characteristics of these complex fluids and established relevant rheological models with a view to simulate the numerical flow in a cylindrical pipeline. Rheograms of these slurries were obtained using a rotational rheometer and were accurately modeled with commonly used yield-pseudoplastic models. The results show that the concentration of solids in a solid–liquid mixture could be increased while maintaining a desired apparent viscosity. Finally, the design equations for the laminar pipe flow of yield pseudoplastics were investigated to highlight the role of rheological studies in this context.

scholarly journals Preparation and Characterization of the Sulfur-Impregnated Natural Zeolite Clinoptilolite for Hg(II) Removal from Aqueous Solutions

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 217
Author(s):  
Marin Ugrina ◽  
Martin Gaberšek ◽  
Aleksandra Daković ◽  
Ivona Nuić
Keyword(s):  
Chemical Modification ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Natural Zeolite ◽  
Contact Time ◽  
Liquid Ratio ◽  
X Ray ◽  
Solid Liquid

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.

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