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.

Analysis of 3-D Numerical Simulation for Soil Cutting by Small Agricultural Machinery

2012 ◽  
Vol 433-440 ◽  
pp. 6182-6189
Author(s):  
Jiang Zhong ◽  
Xian Zhang ◽  
Jian Dong Jiang ◽  
Zhang Feng Zhao
Keyword(s):  
Structural Parameters ◽  
Agricultural Machinery ◽  
Compacted Soil ◽  
Mesh Free ◽  
Particle Hydrodynamics ◽  
Mesh Free Method ◽  
Smoothed Particle ◽  
Soil Cutting ◽  
Large Material ◽  
Cutting Problem

Small agricultural machinery with forward and reverse-rotational rotary blades was proposed for solving the problem of cultivation with compacted soil. Lagrangian smoothed particle hydrodynamics (SPH) based models of forward and reverse-rotational rotary blades were carried out using the LS-DYNA software. SPH is a mesh free method, thus large material distortions that occur in the soil cutting problem are easily managed. In most earth moving machinery, such as bulldozers or tillage tools, the working tool is a blade. Hence for tillage systems, accurately predicting the forces acting on the blade is of prime importance in helping to enhance productivity. Structural parameters of reverse-rotational rotary blade were studied and optimized with orthogonal test and numerical simulating technology. Results show that forward and reverse-rotational rotary tool can independently work for the cutting of compacted soil with different operating resistance. It is perfectly feasible to apply the proposed composite rotary tiller to compacted soil deep-tilling with low power motor. Proper structural parameters of forward and reverse-rotational rotary blades can reduce the power consumption. This method provides theoretical basis for the design of tools.

The Application of Godunov SPH in the Simulation of Energetic Materials

2019 ◽  
Vol 17 (07) ◽  
pp. 1950028
Author(s):  
Man Hu ◽  
Guangyu Wang ◽  
Guirong Liu ◽  
Qing Peng
Keyword(s):  
Energetic Materials ◽  
Solid Mechanics ◽  
Particle Density ◽  
Numerical Study ◽  
Artificial Viscosity ◽  
High Explosives ◽  
Mesh Free ◽  
Particle Hydrodynamics ◽  
Mesh Free Method ◽  
Sph Algorithm

The numerical study of detonation of high explosives has been the interest of researchers over decades. Due to its special advantages in tracking free surface and dealing with large deformation, smoothed particle hydrodynamics (SPH) has been a powerful tool to investigate detonation phenomenon. SPH is a Lagrangian mesh-free method with extensive applications in fluid mechanics and solid mechanics. In the early development of SPH method, artificial viscosity is introduced to suppress unphysical fluctuation. However, the parameters of artificial viscosity often need to be tuned for some simulation, which can be quite time-consuming. Herein, a Riemann solver is integrated in traditional SPH algorithm to eliminate artificial viscosity, which is known as Godunov SPH. First, shock tube problem is studied using the Godunov SPH. The simulation result is compared with that obtained by traditional SPH with artificial viscosity, finite volume method (FVM) and experiment. Then, the Godunov SPH is implemented to investigate the detonation of 1D and 2D polymer-bonded explosive PBX 9501. Various factors that may influence simulation are studied, such as particle density and smoothing length. It is demonstrated that the proposed method is accurate and reliable for the study of detonation of high explosives.

Numerical Simulation of Crushing and Bending Failure of Ice Using SPH

2015 ◽  
Author(s):  
Jitapriya Das ◽  
Sören Ehlers
Keyword(s):  
Sea Ice ◽  
Failure Time ◽  
Free Particle ◽  
Particle Method ◽  
Primary Objective ◽  
Bending Test ◽  
Four Point Bending ◽  
Mesh Free ◽  
Particle Hydrodynamics ◽  
Mesh Free Method

The primary objective of this investigation is to simulate bending and crushing failure of sea ice in a local scale using Smoothed Particle Hydrodynamics (SPH), which being a mesh free method offers a lot of advantages over traditional gridbased approaches. The numerical bending results are compared to earlier simulations of in-situ four-point bending test results and finite element simulations in terms of force, displacement and failure time whereas the crushing failure is compared with experiments conducted by Häusler. The comparison of these SPH-based numerical simulations with the available literature will serve as a basis to discuss the potential advantages and shortcomings of the mesh free particle method used to model failure of sea ice. Furthermore, this developed model will be extended further so as to simulate the actual behaviour of sea ice as ships progress through level ice.

Method of smooth particle hydrodynamics for simulation the failure and relief of the roof of mine working

2018 ◽  
Vol 11 (49) ◽  
pp. 464-475
Author(s):  
Malinnikova O.N. ◽  
◽  
Troimov V.A. ◽  
Shipovskii I.E. ◽  
◽  
...  
Keyword(s):  
Mine Working ◽  
Smooth Particle Hydrodynamics ◽  
Particle Hydrodynamics

scholarly journals Review of smoothed particle hydrodynamics: towards converged Lagrangian flow modelling

2020 ◽  
Vol 476 (2241) ◽  
pp. 20190801
Author(s):  
Steven J. Lind ◽  
Benedict D. Rogers ◽  
Peter K. Stansby
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Graphics Processing Units ◽  
Wave Structure ◽  
Free Form ◽  
Mesh Free ◽  
Weakly Compressible ◽  
Particle Hydrodynamics ◽  
Massively Parallel Computing ◽  
Smoothed Particle ◽  
Graphics Processing

This paper presents a review of the progress of smoothed particle hydrodynamics (SPH) towards high-order converged simulations. As a mesh-free Lagrangian method suitable for complex flows with interfaces and multiple phases, SPH has developed considerably in the past decade. While original applications were in astrophysics, early engineering applications showed the versatility and robustness of the method without emphasis on accuracy and convergence. The early method was of weakly compressible form resulting in noisy pressures due to spurious pressure waves. This was effectively removed in the incompressible (divergence-free) form which followed; since then the weakly compressible form has been advanced, reducing pressure noise. Now numerical convergence studies are standard. While the method is computationally demanding on conventional processors, it is well suited to parallel processing on massively parallel computing and graphics processing units. Applications are diverse and encompass wave–structure interaction, geophysical flows due to landslides, nuclear sludge flows, welding, gearbox flows and many others. In the state of the art, convergence is typically between the first- and second-order theoretical limits. Recent advances are improving convergence to fourth order (and higher) and these will also be outlined. This can be necessary to resolve multi-scale aspects of turbulent flow.

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.

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