scholarly journals Discretization Approaches to Model Metal Cutting with Lagrangian, Arbitrary Lagrangian Eulerian and Smooth Particle Hydrodynamics formulations

PAMM ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Praveen Sridhar ◽  
Kristin M. de Payrebrune
Keyword(s):  
Metal Cutting ◽  
Arbitrary Lagrangian Eulerian ◽  
Smooth Particle Hydrodynamics ◽  
Particle Hydrodynamics

scholarly journals Methods for modelling Air blast on structures in LS-DYNA. Comparison and analysys

2019 ◽  
Vol 21 (1) ◽  
pp. 22-31
Author(s):  
S. P. Bisyk ◽  
I. B. Chepkov ◽  
M. I. Vaskivskyi ◽  
L. S. Davydovskyi ◽  
O. A. Slуvinskуi ◽  
...  
Keyword(s):  
Metal Plate ◽  
Arbitrary Lagrangian Eulerian ◽  
Smooth Particle Hydrodynamics ◽  
Calculation Methods ◽  
Air Blast ◽  
Advantages And Disadvantages ◽  
Particle Hydrodynamics

The results of modeling the effect of an explosion on a metal plate using different calculation methods are presented: LOAD_BLAST; LOAD_BLAST_ENHANCED; Arbitrary Lagrangian Eulerian; Particle Blast Method; Smooth Particle Hydrodynamics, implemented in the LS-DYNA program. The adequacy and accuracy of these methods is estimated, depending on the distance factor to the explosive. Bringing the advantages and disadvantages of each method and recommendations for their application based on the results of this simulation and the experience of the authors.

Computational of Orthogonal Metal Cutting Process Using Smooth Particle Hydrodynamics

2017 ◽  
Vol 867 ◽  
pp. 119-126
Author(s):  
S. Muthusamy ◽  
A Arulmurugu
Keyword(s):  
Finite Element ◽  
Cutting Force ◽  
Metal Cutting ◽  
Cutting Speed ◽  
Cutting Process ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Smooth Particle Hydrodynamics ◽  
Particle Hydrodynamics ◽  
Sph Model

In modern years, simulating metal cutting process used in Finite element method (FEM). The cutting force is used to identify the excessive friction of machining interface and worn out tool. Optimization of machining parameters are used to maintain the precision of the component, power consumption minimized and tool wear reduced. The current project presents the simulated Finite Element SPH Model used for predict the cutting force and associate with experimental confirmation while turning the AA2219-TiB2/ZrB2 metal matrix composites (MMC). Smooth Particle Hydrodynamics (SPH) machining simulation was carried out using a Lagrangian finite element based machining model to predict the cutting force. The turning simulation operation carried out using ANSYS AUTODYN (SPH) software. Machining parameters are cutting speed, feed rate and depth of cut. The results predicted from the SPH analysis virtually close to the results attained from the experimental work. Simulation of machining test using SPH model is preferred over actual cutting test because of it reduce cost and time.

scholarly journals Smoothed Particle Hydrodynamics Simulation of Orthogonal Cutting with Enhanced Thermal Modeling

2021 ◽  
Vol 11 (3) ◽  
pp. 1020
Author(s):  
Mohamadreza Afrasiabi ◽  
Hagen Klippel ◽  
Matthias Roethlin ◽  
Konrad Wegener
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Metal Cutting ◽  
Thermal Modeling ◽  
Orthogonal Cutting ◽  
Detection Algorithm ◽  
Mesh Free ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Boundary Treatments ◽  
Cutting Problems

Smoothed Particle Hydrodynamics (SPH) is a mesh-free numerical method that can simulate metal cutting problems efficiently. The thermal modeling of such processes with SPH, nevertheless, is not straightforward. The difficulty is rooted in the computationally demanding procedures regarding convergence properties and boundary treatments, both known as SPH Grand Challenges. This paper, therefore, intends to rectify these issues in SPH cutting models by proposing two improvements: (1) Implementing a higher-order Laplacian formulation to solve the heat equation more accurately. (2) Introducing a more realistic thermal boundary condition using a robust surface detection algorithm. We employ the proposed framework to simulate an orthogonal cutting process and validate the numerical results against the available experimental measurements.

scholarly journals A Well-Balanced SPH-ALE Scheme for Shallow Water Applications

2021 ◽  
Vol 88 (3) ◽  
Author(s):  
Alberto Prieto-Arranz ◽  
Luis Ramírez ◽  
Iván Couceiro ◽  
Ignasi Colominas ◽  
Xesús Nogueira
Keyword(s):  
Shallow Water ◽  
Source Term ◽  
Arbitrary Lagrangian Eulerian ◽  
Flat Bottom ◽  
Riemann Solvers ◽  
Eulerian Formulation ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Numerical Fluxes ◽  
And Behavior

AbstractIn this work, a new discretization of the source term of the shallow water equations with non-flat bottom geometry is proposed to obtain a well-balanced scheme. A Smoothed Particle Hydrodynamics Arbitrary Lagrangian-Eulerian formulation based on Riemann solvers is presented to solve the SWE. Moving-Least Squares approximations are used to compute high-order reconstructions of the numerical fluxes and, stability is achieved using the a posteriori MOOD paradigm. Several benchmark 1D and 2D numerical problems are considered to test and validate the properties and behavior of the presented schemes.

scholarly journals A parameter-free total Lagrangian smooth particle hydrodynamics algorithm applied to problems with free surfaces

2021 ◽  
Author(s):  
Kenny W. Q. Low ◽  
Chun Hean Lee ◽  
Antonio J. Gil ◽  
Jibran Haider ◽  
Javier Bonet
Keyword(s):  
Ad Hoc ◽  
Wide Spectrum ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Point Of View ◽  
Numerical Dissipation ◽  
Lagrangian Description ◽  
Smooth Particle Hydrodynamics ◽  
Particle Hydrodynamics ◽  
Sph Algorithm

AbstractThis paper presents a new Smooth Particle Hydrodynamics computational framework for the solution of inviscid free surface flow problems. The formulation is based on the Total Lagrangian description of a system of first-order conservation laws written in terms of the linear momentum and the Jacobian of the deformation. One of the aims of this paper is to explore the use of Total Lagrangian description in the case of large deformations but without topological changes. In this case, the evaluation of spatial integrals is carried out with respect to the initial undeformed configuration, yielding an extremely efficient formulation where the need for continuous particle neighbouring search is completely circumvented. To guarantee stability from the SPH discretisation point of view, consistently derived Riemann-based numerical dissipation is suitably introduced where global numerical entropy production is demonstrated via a novel technique in terms of the time rate of the Hamiltonian of the system. Since the kernel derivatives presented in this work are fixed in the reference configuration, the non-physical clumping mechanism is completely removed. To fulfil conservation of the global angular momentum, a posteriori (least-squares) projection procedure is introduced. Finally, a wide spectrum of dedicated prototype problems is thoroughly examined. Through these tests, the SPH methodology overcomes by construction a number of persistent numerical drawbacks (e.g. hour-glassing, pressure instability, global conservation and/or completeness issues) commonly found in SPH literature, without resorting to the use of any ad-hoc user-defined artificial stabilisation parameters. Crucially, the overall SPH algorithm yields equal second order of convergence for both velocities and pressure.

scholarly journals Formation of Prestellar Cores via Non-Isothermal Gas Fragmentation

2015 ◽  
Vol 32 ◽  
Author(s):  
S. Anathpindika
Keyword(s):  
Gravitational Instability ◽  
Gas Flows ◽  
Smooth Particle Hydrodynamics ◽  
Three Phase ◽  
Prestellar Cores ◽  
Particle Hydrodynamics ◽  
Unstable Medium ◽  
Stage Process ◽  
Isothermal Gas ◽  
Gas Accretion

AbstractSheet-like clouds are common in turbulent gas and perhaps form via collisions between turbulent gas flows. Having examined the evolution of an isothermal shocked slab in an earlier contribution, in this work we follow the evolution of a sheet-like cloud confined by (thermal) pressure and gas in it is allowed to cool. The extant purpose of this endeavour is to study the early phases of core-formation. The observed evolution of this cloud supports the conjecture that molecular clouds themselves are three-phase media (comprising viz. a stable cold and warm medium, and a third thermally unstable medium), though it appears, clouds may evolve in this manner irrespective of whether they are gravitationally bound. We report, this sheet fragments initially due to the growth of the thermal instability (TI) and some fragments are elongated, filament-like. Subsequently, relatively large fragments become gravitationally unstable and sub-fragment into smaller cores. The formation of cores appears to be a three stage process: first, growth of the TI leads to rapid fragmentation of the slab; second, relatively small fragments acquire mass via gas-accretion and/or merger and third, sufficiently massive fragments become susceptible to the gravitational instability and sub-fragment to form smaller cores. We investigate typical properties of clumps (and smaller cores) resulting from this fragmentation process. Findings of this work support the suggestion that the weak velocity field usually observed in dense clumps and smaller cores is likely seeded by the growth of dynamic instabilities. Simulations were performed using the smooth particle hydrodynamics algorithm.

scholarly journals Modelling Closed-Die Forging Operations Using Total Lagrangian Smooth Particle Hydrodynamics

2019 ◽  
Author(s):  
Anthony Manson
Keyword(s):  
Large Deformation ◽  
Smooth Particle Hydrodynamics ◽  
Material Flows ◽  
Forging Process ◽  
Mesh Free ◽  
Closed Die Forging ◽  
Particle Hydrodynamics ◽  
Mesh Free Method ◽  
Large Material ◽  
Simulation Parameters

Total Lagrangian Smooth Particle Hydrodynamics (TLSPH) has been applied to a set of non-trivial, commercially interesting forging examples.Being a mesh-free method, TLSPH can conveniently simulate processes having large deformation and material separation.Test cases were designed that were characterized by large material flows having large changes in grain connectivity.The implementation used, Smooth Mach Dynamics (SMD), provided tunable simulation parameters that enabled the simulation to optimally match each case.The results showed that the TLSPH/SMD has the potential to model the metal forging process efficiently without numerical instabilities.Each case studied required adaptation of the simulation parameters to optimize the results.

scholarly journals ASSESSMENT OF THE CAPABILITY OF 3D STRATIFIED FLOW FINITE ELEMENT MODEL IN CHARACTERIZING MEANDER DYNAMICS

2015 ◽  
pp. 155-166
Author(s):  
Dwinanti Rika Marthanty ◽  
Herr Soeryantono ◽  
Erick CARLIER ◽  
Dwita Sutjinigsih
Keyword(s):  
Finite Element ◽  
Sediment Transport ◽  
Finite Element Model ◽  
Flow Characteristics ◽  
Distribution Patterns ◽  
Element Model ◽  
Boundary Element Methods ◽  
Arbitrary Lagrangian Eulerian ◽  
Particle Hydrodynamics ◽  
Complex Phenomena

There have been attempts to simulate meander dynamics (Langbein and Leopold 1966, Oodgard 1989, Campoerale et. al 2007, da Silva and El-Tahawy 2008, Duan and Julien 2010, Blanckaert and de Vriend 2010, Esfahani and Keshavarzi 2011). Meandering geometry is complex phenomena (Chanson 2004, Wu 2008), this would include the dynamics of flow properties and of morphology. Simulating meander flow dynamics is mostly popular using either Finite Element Method (FEM) or Finite Volume Method (FVM) where are based on Eulerian description, and based on stationer grid-based methods (Wormleaton and Ewunetu 2006, Wu 2008, Duan and Julien 2010, Gomez-Gesteira et. al 2010). As such this model is lack of capability in simulating the dynamics of meander morphology; much effort is put through to overcome this issue with such as Smoothed Particle Hydrodynamics (SPH), Boundary Element Methods, Arbitrary Lagrangian Eulerian, etc. This paper has two objectives; to identify meander flow characteristics and sediment transport distribution patterns, and to simulate meander flow characteristics and sediment transport distribution patterns using FEM. This study has identified that the key of dynamics of flow characteristics are helical flow and coherent structures, and the key of dynamics of transport characteristics are erosion-deposition zone patterns. The finite element model using in this study, RMA has shown its capability to simulate the meander key characteristics above, for small deflection angles (30°) location of maximum erosion-deposition zones near the crossover of the sinuosity, for intermediate deflection angles (70°) location of maximum erosion-deposition zones between the crossover and apex of the sinuosity, and for large deflection angles (110°) location of maximum erosion-deposition zones near the apex of the sinuosity, these are agreed with experiments of Odgaard 1989, da Silva 2006, da Silva et. al 2006, and Esfahani and Keshavarzi (2012). These results can be used as a reference to develop a method to model meander morpho-dynamics.

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