Response Analysis of Submerged Floating Tunnel Hit by Submarine Based on Smoothed-Particle Hydrodynamics

This paper presents the theoretical investigation on the damage of the submerged floating tunnel (SFT) under extreme loads. Water was modeled by smoothed-particle hydrodynamics (SPH). Anchor cables, SFT, and submarine were modeled by the finite element method (FEM). Penetrating phenomenon in the calculation process was achieved by the penalty function, and the fluid-solid coupling effect was also considered in the simulation. The process of a submarine striking on the SFT was studied based on the commercial software. The relationships between the energy of the water, submarine, and SFT were studied. The structural and human damages were evaluated using the kinematics and kinetic parameters of the SFT according to the relevant criterion. The results indicate that the SPH-FEM coupling method is suitable to investigate the impact of the SFT in the water. The initial kinetic energy of the submarine is mainly converted into kinetic energy of the water and internal energy of the tunnel. The kinematic parameters at the impact point reach a peak value. The kinematic parameters at the anchor cables reach the minimum value, so the anchor cables can inhibit the development of disaster significantly. The SPH-FEM coupling method can be helpful for collision and explosion analysis of the SFT.

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Numerical Simulation of Non-Homogeneous Viscous Debris-Flows Based on the Smoothed Particle Hydrodynamics (SPH) Method

Water ◽

10.3390/w11112314 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2314 ◽

Cited By ~ 4

Author(s):

Shu Wang ◽

Anping Shu ◽

Matteo Rubinato ◽

Mengyao Wang ◽

Jiping Qin

Keyword(s):

Debris Flow ◽

Water Content ◽

Smoothed Particle Hydrodynamics ◽

Debris Flows ◽

Sph Method ◽

Particle Hydrodynamics ◽

Sph Model ◽

Smoothed Particle ◽

The Impact ◽

Kinetic And Potential Energies

Non-homogeneous viscous debris flows are characterized by high density, impact force and destructiveness, and the complexity of the materials they are made of. This has always made these flows challenging to simulate numerically, and to reproduce experimentally debris flow processes. In this study, the formation-movement process of non-homogeneous debris flow under three different soil configurations was simulated numerically by modifying the formulation of collision, friction, and yield stresses for the existing Smoothed Particle Hydrodynamics (SPH) method. The results obtained by applying this modification to the SPH model clearly demonstrated that the configuration where fine and coarse particles are fully mixed, with no specific layering, produces more fluctuations and instability of the debris flow. The kinetic and potential energies of the fluctuating particles calculated for each scenario have been shown to be affected by the water content by focusing on small local areas. Therefore, this study provides a better understanding and new insights regarding intermittent debris flows, and explains the impact of the water content on their formation and movement processes.

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The Role of Discs in the Collapse and Fragmentation of Prestellar Cores

Publications of the Astronomical Society of Australia ◽

10.1017/pasa.2015.55 ◽

2016 ◽

Vol 33 ◽

Cited By ~ 1

Author(s):

O. Lomax ◽

A. P. Whitworth ◽

D. A. Hubber

Keyword(s):

Kinetic Energy ◽

Smoothed Particle Hydrodynamics ◽

Low Mass Stars ◽

Gravitational Instabilities ◽

Disc Material ◽

Prestellar Cores ◽

Particle Hydrodynamics ◽

Smoothed Particle ◽

Low Mass

AbstractDisc fragmentation provides an important mechanism for producing low-mass stars in prestellar cores. Here, we describe smoothed particle hydrodynamics simulations which show how populations of prestellar cores evolve into stars. We find the observed masses and multiplicities of stars can be recovered under certain conditions.First, protostellar feedback from a star must be episodic. The continuous accretion of disc material on to a central protostar results in local temperatures which are too high for disc fragmentation. If, however, the accretion occurs in intense outbursts, separated by a downtime of ~ 104yr, gravitational instabilities can develop and the disc can fragment.Second, a significant amount of the cores’ internal kinetic energy should be in solenoidal turbulent modes. Cores with less than a third of their kinetic energy in solenoidal modes have insufficient angular momentum to form fragmenting discs. In the absence of discs, cores can fragment but results in a top-heavy distribution of masses with very few low-mass objects.

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Modeling Hypervelocity Impacts Using Smoothed Particle Hydrodynamics

Volume 4: Fluid-Structure Interaction ◽

10.1115/pvp2018-84609 ◽

2018 ◽

Author(s):

M. Ganser ◽

B. van der Linden ◽

C. G. Giannopapa

Keyword(s):

Smoothed Particle Hydrodynamics ◽

Large Deformations ◽

Hypervelocity Impact ◽

Density Fluctuations ◽

Computational Domain ◽

Simulation Tool ◽

Hypervelocity Impacts ◽

Particle Hydrodynamics ◽

Smoothed Particle ◽

The Impact

Hypervelocity impacts occur in outer space where debris and micrometeorites with a velocity of 2 km/s endanger spacecraft and satellites. A proper shield design, e.g. a laminated structure, is necessary to increase the protection capabilities. High velocities result in massive damages. The resulting large deformations can hardly be tackled with mesh based discretization methods. Smoothed Particle Hydrodynamics (SPH), a Lagrangian meshless scheme, can resolve large topological changes whereas it still follows the continuous formulation. Derived by variational principles, SPH is able to capture large density fluctuations associated with hypervelocity impacts correctly. Although the impact region is locally limited, a much bigger domain has to be discretized because of strong outgoing pressure waves. A truncation of the computational domain is preferable to save computational power, but this leads to artificial reflections which influence the real physics. In this paper, hypervelocity impact (HVI) is modelled by means of basic conservation assumptions leading to the Euler equations of fluid dynamics accompanied by the Mie-Grueneisen equation of state. The newly developed simulation tool SPHlab presented in this work utilizes the discretization method smoothed particle hydrodynamics (SPH) to capture large deformations. The model is validated through a number of test cases. Different approaches are presented for non-reflecting boundaries in order to tackle artificial reflections on a computational truncated domain. To simulate an HVI, the leading continuous equations are derived and the simulation tool SPHlab is developed. The method of characteristics allows to define proper boundary fluxes by removing the inwards travelling information. One- and two-dimensional model problems are examined which show excellent absorption behaviour. An hypervelocity impact into a laminated shield is simulated and analysed and a simple damage model is introduced to model a spallation failure mode.

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Application of Smoothed Particle Hydrodynamics (SPH) for the Simulation of Flow-like Landslides on 3D Terrains

10.21203/rs.3.rs-1222497/v1 ◽

2022 ◽

Author(s):

Binghui Cui ◽

Liaojun Zhang

Keyword(s):

Risk Assessment ◽

Smoothed Particle Hydrodynamics ◽

Disaster Mitigation ◽

Sph Method ◽

Landslide Event ◽

Particle Hydrodynamics ◽

Smoothed Particle ◽

Simulation Results ◽

Mitigation Design ◽

The Impact

Abstract Flow-type landslide is one type of landslide that generally exhibits characteristics of high flow velocities, long jump distances, and poor predictability. Simulation of it facilitates propagation analysis and provides solutions for risk assessment and mitigation design. The smoothed particle hydrodynamics (SPH) method has been successfully applied to the simulation of two-dimensional (2D) and three-dimensional (3D) flow-like landslides. However, the influence of boundary resistance on the whole process of landslide failure is rarely discussed. In this study, a boundary algorithm considering the friction is proposed, and integrated into the boundary condition of the SPH method, and its accuracy is verified. Moreover, the Navier-Stokes equation combined with the non-Newtonian fluid rheology model was utilized to solve the dynamic behavior of the flow-like landslide. To verify its performance, the Shuicheng landslide event, which occurred in Guizhou, China, was taken as a case study. In the 2D simulation, a sensitivity analysis was conducted, and the results showed that the shearing strength parameters have more influence on the computation accuracy in comparison with the coefficient of viscosity. Afterwards, the dynamic characteristics of the landslide, such as the velocity and the impact area, were analyzed in the 3D simulation. The simulation results are in good agreement with the field investigations. The simulation results demonstrate that the SPH method performs well in reproducing the landslide process, and facilitates the analysis of landslide characteristics as well as the affected areas, which provides a scientific basis for conducting the risk assessment and disaster mitigation design.

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Numerical study of rainstorm influence on parachute airdropping based on the smoothed particle hydrodynamics/arbitrary Lagrangian–Eulerian coupling method

Journal of Engineered Fibers and Fabrics ◽

10.1177/1558925020915616 ◽

2020 ◽

Vol 15 ◽

pp. 155892502091561

Author(s):

Linbo Yan ◽

Zhengkai Sun ◽

Han Cheng

Keyword(s):

Smoothed Particle Hydrodynamics ◽

Wind Field ◽

Numerical Study ◽

Great Influence ◽

Coupling Method ◽

Influential Factor ◽

Arbitrary Lagrangian Eulerian ◽

Particle Hydrodynamics ◽

Smoothed Particle ◽

And Performance

In order to study the influence of rainstorm on parachute dropping, the smoothed particle hydrodynamics/arbitrary Lagrangian–Eulerian coupling method is proposed. Finite elements are used to describe the continuous material such as fabric and air flow field, and the smoothed particle hydrodynamics particles are used to describe the discrete raindrops. The coupling between different fluid and structure is realized by penalty function. In order to distinguish the most influential factor of rainstorm environment on parachute, the effects of raindrop field and wind field in rainstorm are studied, respectively. It could be found that the raindrop fields with different droplet sizes have little effect on the parachute’s shape, opening shock, and performance according to the comparative analysis, while the vertical wind field has a great influence on parachute’s deceleration performance. The wind field, not the raindrop field, is the most important factor affecting the parachute’s deceleration performance. The method and conclusions in this article could provide some references for parachute design.

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Analysis of surface-erosion mechanism due to impacts of freely rotating angular particles using smoothed particle hydrodynamics erosion model

Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology ◽

10.1177/1350650117700750 ◽

2017 ◽

Vol 231 (12) ◽

pp. 1537-1551 ◽

Cited By ~ 3

Author(s):

Xiangwei Dong ◽

Zengliang Li ◽

Qi Zhang ◽

Wei Zeng ◽

G.R. Liu

Keyword(s):

Smoothed Particle Hydrodynamics ◽

Impact Angle ◽

Surface Erosion ◽

Free Rotation ◽

Erosion Model ◽

Erosion Mechanism ◽

Particle Hydrodynamics ◽

Smoothed Particle ◽

The Impact ◽

Angular Particles

The free rotation of an angular particle during its impact on ductile surfaces is an important factor that influences the erosion mechanism. However, the phenomenon cannot be easily revealed experimentally because the incident conditions cannot be accurately controlled. In this study, a novel erosion model based on smoothed particle hydrodynamics method is proposed to simulate single and multiple impacts of particles with specified angularities on a ductile surface. The model can simulate a particle having free rotation during the impact process and initial rotation prior to the impact. The results show that the impact angle and initial orientation significantly affect the tumbling behavior, which determines the erosion mechanism. Moreover, the initial rotation is investigated by assigning an initial angular velocity to the particle at the onset of impact. The proposed smoothed particle hydrodynamics erosion model is proven to be a promising complementary method that supports experimental techniques. This study provides insight for understanding the fundamental mechanisms of surface erosion due to angular particles.

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Numerical Simulation of Impact Behavior of Ceramic Coatings Using Smoothed Particle Hydrodynamics Method

Journal of Engineering Materials and Technology ◽

10.1115/1.4049021 ◽

2020 ◽

pp. 1-25

Author(s):

Jian Zhang ◽

Zhe Lu ◽

Sugrim Sagar ◽

Hyunhee Choi ◽

Heesung Park ◽

...

Keyword(s):

Spherical Particle ◽

Smoothed Particle Hydrodynamics ◽

Coating Layer ◽

Ceramic Coatings ◽

Impact Angle ◽

Impact Behavior ◽

Sph Method ◽

Particle Hydrodynamics ◽

Smoothed Particle ◽

The Impact

Abstract In this work, the impact behavior of an alumina spherical particle on alumina coating is modeled using the smoothed particle hydrodynamics (SPH) method. The effects of impact angle (0°, 30°, and 60°) and velocity (100 m/s, 200 m/s, and 300 m/s) on the morphology changes of the impact pit and impacting particle, and their associated stress and energy are investigated. The results show that the combination of impact angle of 0° and velocity of 300 m/s produces the highest penetration depth and largest stress and deformation in the coating layer, while the combination of 100 m/s & 60° causes the minimum damage to the coating layer. This is because the penetration depth is determined by the vertical velocity component difference between the impacting particle and the coating layer, but irrelevant to the horizontal component. The total energy of the coating layer increases with the time, while the internal energy increases with the time after some peak values, which is due to energy transmission from the spherical particle to the coating layer and the stress shock waves. The energy transmission from impacting particle to coating layer increases with the increasing particle velocity, and decreases with the increasing inclined angle. The simulated impact pit morphology is qualitatively similar to the experimental observation. This work demonstrates that the SPH method is useful to analyze the impact behavior of ceramic coatings.

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Multigrain Smoothed Particle Hydrodynamics and Hertzian Contact Modeling of the Grinding Force in Atherectomy

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4042603 ◽

2019 ◽

Vol 141 (4) ◽

Cited By ~ 1

Author(s):

Yihao Zheng ◽

Yao Liu ◽

Yang Liu ◽

Albert J. Shih

Keyword(s):

Smoothed Particle Hydrodynamics ◽

Cutting Forces ◽

Grinding Force ◽

Grinding Wheel ◽

Hertz Contact ◽

Grinding Forces ◽

Calcified Plaque ◽

Particle Hydrodynamics ◽

Smoothed Particle ◽

The Impact

This study investigated the grinding force in rotational atherectomy, a clinical procedure that uses a high-speed grinding wheel to remove hardened, calcified plaque inside the human arteries. The grinding force, wheel motion, and ground surface were measured based on a ring-shape bovine bone surrogate for the calcified plaque. At 135,000, 155,000, and 175,000 rpm wheel rotational speed, the grinding forces were 1.84, 1.92, and 2.22 N and the wheel orbital speeds were 6060, 6840, and 7800 rpm, respectively. The grinding wheel was observed to bounce on the wall of the bone surrogate, leaving discrete grinding marks. Based on this observation, we modeled the grinding force in two components: impact and cutting forces. The impact force between the grinding wheel and the bone surrogate was calculated by the Hertz contact model. A multigrain smoothed particle hydrodynamics (SPH) model was established to simulate the cutting force. The grinding wheel model was built according to the wheel surface topography scanned by a laser confocal microscope. The workpiece was modeled by kinematic-geometrical cutting. The simulation predicted a cutting force of 41, 51, and 99 mN at the three investigated wheel rotational speeds. The resultant grinding forces, combining the impact and cutting forces modeled by the Hertz contact and SPH simulation, matched with the experimental measurements with relative errors less than 10%.

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Improved δ-SPH Scheme with Automatic and Adaptive Numerical Dissipation

Water ◽

10.3390/w12102858 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2858 ◽

Cited By ~ 1

Author(s):

Abdelkader Krimi ◽

Luis Ramírez ◽

Sofiane Khelladi ◽

Fermín Navarrina ◽

Michael Deligant ◽

...

Keyword(s):

Kinetic Energy ◽

Smoothed Particle Hydrodynamics ◽

Numerical Scheme ◽

Compressible Flows ◽

Adaptive Method ◽

Numerical Dissipation ◽

Numerical Examples ◽

Weakly Compressible ◽

Particle Hydrodynamics ◽

Smoothed Particle

In this work we present a δ-Smoothed Particle Hydrodynamics (SPH) scheme for weakly compressible flows with automatic adaptive numerical dissipation. The resulting scheme is a meshless self-adaptive method, in which the introduced artificial dissipation is designed to increase the dissipation in zones where the flow is under-resolved by the numerical scheme, and to decrease it where dissipation is not required. The accuracy and robustness of the proposed methodology is tested by solving several numerical examples. Using the proposed scheme, we are able to recover the theoretical decay of kinetic energy, even where the flow is under-resolved in very coarse particle discretizations. Moreover, compared with the original δ-SPH scheme, the proposed method reduces the number of problem-dependent parameters.

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Pressure evaluation during dam break using weakly compressible SPH

EPJ Web of Conferences ◽

10.1051/epjconf/201921302030 ◽

2019 ◽

Vol 213 ◽

pp. 02030

Author(s):

Petr Jančík ◽

Tomáš Hyhlík

Keyword(s):

Experimental Data ◽

Smoothed Particle Hydrodynamics ◽

Two Dimensions ◽

Dam Break ◽

Kinematics And Dynamics ◽

Sph Method ◽

Weakly Compressible ◽

Particle Hydrodynamics ◽

Smoothed Particle ◽

The Impact

This paper presents a solution of a dam break problem in two dimensions obtained with smoothed particle hydrodynamics (SPH) method. The main focus is on pressure evaluation during the impact on the wall. The used numerical method and the way of pressure evaluation are described in detail. The numerical results of the kinematics and dynamics of the flow are compared with experimental data from the literature. The abilities and limitations of the used methods are discussed.

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