scholarly journals Towards a Smoothed Particle Hydrodynamics Algorithm for Shocks Through Layered Materials

2013 ◽  
Author(s):  
Iason Zisis ◽  
Bas van der Linden ◽  
Christina Giannopapa
Keyword(s):  
Shock Waves ◽  
Density Distribution ◽  
Smoothed Particle Hydrodynamics ◽  
Shock Loading ◽  
Numerical Technique ◽  
Layered Materials ◽  
Functionally Graded ◽  
Particle Hydrodynamics ◽  
Graded Material ◽  
Smoothed Particle

Hypervelocity impacts (HVIs) are collisions at velocities greater than the target object’s speed of sound. Such impacts produce pressure waves that generate sharp and sudden changes in the density of the materials. These are propagated as shock waves. Previous computational research has given insight into this shock loading for the case of homogeneous materials. Shock-wave propagation through materials with discontinuous density distribution has not been considered in depth yet. Smoothed Particle Hydrodynamics (SPH) is a numerical technique, which has been extensively used for the simulation of HVIs. It is especially suitable for this purpose as it describes both the solid and fluid-like behavior effectively as well as the violent breakup of the material under impact. In previous studies on SPH, impact loading of composite materials was modeled by homogenization of the material, or under assumption of being a so-called functionally graded material (FGM). Both these models neglect the reflection-transmission effects on the interface between materials of different density. In this paper the shock loading of layered materials is studied. A modification to the standard SPH method is developed and tested, that incorporates materials with purely discontinuous density distribution. The developed method’s performance at simple shock loading cases is investigated; reflection-transmission patterns of shock-waves through layered materials are discussed, along with a parametric study of the governing parameters.

scholarly journals Interaction of Shock Waves with Discrete Gas Inhomogeneities: A Smoothed Particle Hydrodynamics Approach

2019 ◽  
Vol 9 (24) ◽  
pp. 5435 ◽  
Author(s):  
Andrea Albano ◽  
Alessio Alexiadis
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Shock Tube ◽  
Smoothed Particle Hydrodynamics ◽  
Particle Hydrodynamics ◽  
Interaction Of Shock Waves ◽  
Smoothed Particle ◽  
Different Shapes ◽  
The Difference

In this study, we propose a smoothed particle hydrodynamics model for simulating a shock wave interacting with cylindrical gas inhomogeneities inside a shock tube. When the gas inhomogeneity interacts with the shock wave, it assumes different shapes depending on the difference in densities between the gas inhomogeneity and the external gas. The model uses a piecewise smoothing length approach and is validated by comparing the results obtained with experimental and CFD data available in the literature. In all the cases considered, the evolution of the inhomogeneity is similar to the experimental shadowgraphs and is at least as accurate as the CFD results in terms of timescale and shape of the gas inhomogeneity.

Investigation of the Dynamic Response of Functionally Graded Materials Using Smoothed Particle Hydrodynamics

2012 ◽  
Vol 586 ◽  
pp. 111-116 ◽  
Author(s):  
Gui Ming Rong ◽  
Hiroyuki Kisu
Keyword(s):  
Functionally Graded Materials ◽  
Smoothed Particle Hydrodynamics ◽  
Functionally Graded ◽  
Two Dimensional ◽  
Inhomogeneous Materials ◽  
Graded Materials ◽  
Stress Pulse ◽  
Benchmark Calculation ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

In the present study, the problem of functionally graded materials (FGMs) under a stress pulse is analyzed based on smoothed particle hydrodynamics (SPH) using the formulation for large deformation. First, the formulation of SPH for this problem is described, and a benchmark calculation is performed and compared to one-dimensional analytical solutions. The behavior of FGMs subjected to a stress pulse is then investigated for several cases, including various distributions of inhomogeneous materials and two-dimensional problems with different boundary conditions. It is found that in the two-dimensional case, if there is a free boundary not parallel to the direction of the external force, the influence from this boundary cannot be ignored.

scholarly journals Non-Symmetrical Collapse of an Empty Cylindrical Cavity Studied with Smoothed Particle Hydrodynamics

2021 ◽  
Vol 11 (8) ◽  
pp. 3500
Author(s):  
Andrea Albano ◽  
Alessio Alexiadis
Keyword(s):  
Shock Waves ◽  
Smoothed Particle Hydrodynamics ◽  
Cylindrical Cavity ◽  
High Velocity ◽  
Pressure Field ◽  
Anisotropic Pressure ◽  
Cavity Radius ◽  
Double Peaks ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

The non-symmetrical collapse of an empty cylindrical cavity is modeled using Smoothed Particle Hydrodynamics. The presence of a nearby surface produces an anisotropic pressure field generating a high-velocity jet that hits the surface. The collapse follows a different dynamic based on the initial distance between the center of the cavity and the surface. When the distance is greater than the cavity radius (detached cavity) the surface is hit by traveling shock waves. When the distance is less than the cavity radius (attached cavity) the surface is directly hit by the jet and later by other shock waves generated in the last stages of the of the collapse. The results show that the surface is hit by a stronger shock when distance between the center of the cavity and the surface is zero while showing more complex double peaks behavior for other distances.

scholarly journals Landslides and tsunamis predicted by incompressible smoothed particle hydrodynamics (SPH) with application to the 1958 Lituya Bay event and idealized experiment

2017 ◽  
Vol 473 (2199) ◽  
pp. 20160674 ◽  
Author(s):  
A. M. Xenakis ◽  
S. J. Lind ◽  
P. K. Stansby ◽  
B. D. Rogers
Keyword(s):  
Turbulent Flows ◽  
Smoothed Particle Hydrodynamics ◽  
Initial Conditions ◽  
Numerical Technique ◽  
Computational Techniques ◽  
Highly Nonlinear ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Run Up ◽  
Multi Phase

Tsunamis caused by landslides may result in significant destruction of the surroundings with both societal and industrial impact. The 1958 Lituya Bay landslide and tsunami is a recent and well-documented terrestrial landslide generating a tsunami with a run-up of 524 m. Although recent computational techniques have shown good performance in the estimation of the run-up height, they fail to capture all the physical processes, in particular, the landslide-entry profile and interaction with the water. Smoothed particle hydrodynamics (SPH) is a versatile numerical technique for describing free-surface and multi-phase flows, particularly those that exhibit highly nonlinear deformation in landslide-generated tsunamis. In the current work, the novel multi-phase incompressible SPH method with shifting is applied to the Lituya Bay tsunami and landslide and is the first methodology able to reproduce realistically both the run-up and landslide-entry as documented in a benchmark experiment. The method is the first paper to develop a realistic implementation of the physics that in addition to the non-Newtonian rheology of the landslide includes turbulence in the water phase and soil saturation. Sensitivity to the experimental initial conditions is also considered. This work demonstrates the ability of the proposed method in modelling challenging environmental multi-phase, non-Newtonian and turbulent flows.

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