SPH SIMULATIONS OF HYPERVELOCITY IMPACT OF AL SPHERES ON MULTI-PLATE STRUCTURES

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1604-1611 ◽  
Author(s):  
QING-MING ZHANG ◽  
REN-RONG LONG ◽  
ZHI-FANG LIU ◽  
FENG-LEI HUANG

A series of numerical simulations using SPH (Smoothed Particle Hydrodynamics) method were carried out to study the hypervelocity impact of aluminum spheres on multi-plate structures. Both the morphologic characteristics of debris clouds and the damage of intermediate plates were investigated. The possible damage effects of debris cloud threat on back wall were also described qualitatively. Results showed that, comparing with single plate or double-plate structures, the multi-plate structure has higher resistance capacity to the impact from hypervelocity particles. Hence the multi-plate shield structure has a better shielding performance with a reduction in weight of the structure. It provides a promising alternative to the traditional shield in the spacecraft shield design.

Author(s):  
M. Ganser ◽  
B. van der Linden ◽  
C. G. Giannopapa

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.


2020 ◽  
Author(s):  
Shuai Li ◽  
Xiaoqing Chen ◽  
Chong Peng ◽  
Jiangang Chen

<p>Drainage channel with step-pool systems are widely used to control debris flow. However, the blocking of debris flow often gives rise to local damage at the steps and baffles. Hence, the estimation of impact force of debris flow is crucial for design step-pools channel. This paper presents a numerical study on the impact behavior of debris flows using SPH (Smoothed Particle Hydrodynamics) method. Some important parameters, such as the baffle shape (square, triangle, and trapezoid) and the densities of debris flows are considered to examine their influence on the impact force. The results show that the largest peak impact force is obtained at the second last baffle, rather than the first baffle. Moreover, the square baffle gives rise to the largest impact force whereas the triangle baffle bears the smallest one among the three baffles. Generally, the peak impact force increases with increasing the inflow density. However, a threshold density, beyond which the peak impact force will decrease, is suggested by the simulations. Based on the numerical results, an improved expression to predict the impact force considering the inclined angle of baffle is proposed.</p>


2012 ◽  
Vol 531-532 ◽  
pp. 695-698
Author(s):  
Hui Lin Zhou ◽  
Hui Yong Yu ◽  
Ming Hua Pang

The Smoothed Particle Hydrodynamics (SPH) method is a very important method to resolve hypervelocity problems and the basic theory of SPH method is introduced here. Then the three dimensional hypervelocity impact problems are simulated by using the model of chair. The results of SPH analysis show that (SPH) method is a numerical calculation method to resolve hypervelocity problems without mesh model but the particle model must be getting to calculate and the program code is less than other method. By analysis the results of the simulation is reasonable and very similar to the test result. It can be concluded that the advantages of SPH demonstrated make it a good and an ideal method to simulate the impact problem and other problems.


2019 ◽  
Vol 89 (8) ◽  
pp. 1213
Author(s):  
В.А. Кузьмин ◽  
С.И. Герасимов ◽  
А.В. Зубанков ◽  
А.Г. Сироткина ◽  
Е.П. Акашева ◽  
...  

The results of the computational and experimental study of the features of the impact of the impactor with the barrier simulating the screen shield of the spacecraft are presented, the pictures of fragmentation of the impactor and the barrier are presented. Numerical calculations were performed using the SPH (Smoothed Particle Hydrodynamics) method. In the experiment, the impactor was accelerated using a two-stage light-gas gun, the state of the barrier and the impactor at the time of their interaction was controlled using x-ray and high-speed video camera. Start-up of the recording equipment was carried out by means of induction sections. The comparative analysis of results of numerical calculation and experiment is given.


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