Numerical Study of Overdriven Detonation Phenomenon

2005 ◽  
Author(s):  
K. Mahmadi ◽  
M. Souli ◽  
N. Aquelet
Keyword(s):  
Numerical Study ◽  
Detonation Pressure ◽  
Explicit Finite Element ◽  
Structure Interaction ◽  
High Velocity Impacts ◽  
Detonation Process ◽  
Material Points ◽  
Overdriven Detonation ◽  
Detonation Phenomenon ◽  
Good Agreement

The overdriven detonation refers to detonation process in which the main detonation parameters, such as detonation pressure and propagating velocity, exceed the corresponding Chapman-Jouguet (C-J) values. This kind of detonation can be occurred when the flyer plate of high velocity impacts the explosive. So, in this work numerical simulation of overdriven detonation (following O.D.D.) phenomenon, which brings out higher detonation pressures than C-J pressure of an explosive is considered. The shock-structure interaction in this fast event is modeled by a penalty coupling, which permits to couple a Lagrangian mesh of the plate to material points of a multi-material Eulerian flow. This technique has been used successfully in many areas of applications, including automotive and industrial fields. By using an explicit finite element method, a good agreement between numerical and experimental results will valid penalty coupling capabilities to solve accurately O.D.D. phenomenon.

The Performance of Pressure Vessel Using Concentric Double Cylindrical High Explosive

2004 ◽  
Vol 126 (4) ◽  
pp. 409-413 ◽  
Author(s):  
Toru Hamada ◽  
Yuichi Nakamura ◽  
Shigeru Itoh
Keyword(s):  
High Velocity ◽  
High Explosive ◽  
Maximum Pressure ◽  
Detonation Pressure ◽  
Low Velocity ◽  
High Explosives ◽  
Detonation Process ◽  
Set Up ◽  
Overdriven Detonation ◽  
Detonation Phenomenon

The detonation pressure from the steady detonation of high explosives is a characteristic. Nevertheless, in materials processing using high explosives, there are cases when the detonation pressure does not match the intended pressure. In this investigation, as a new method of generating the overdriven detonation effectively, a double cylindrical high explosive set up using two kinds of explosives was developed, and its basic performance is analyzed. The concentric double cylindrical high explosive set up was composed of a high velocity explosive and a low velocity explosive, and the overdriven detonation was performed in the low velocity explosive. In this experiment, the ion gap was set up in the high velocity explosive and low velocity explosive respectively, and the detonation velocity was measured. The detonation pressure was also measured by setting up a manganin gauge (Kyowa Electric Instrument Co., Ltd.,) at the position where the generation of the overdriven detonation phenomenon was expected. Furthermore, the overdriven detonation process of the concentric double cylindrical high explosive was continually observed by numerical analysis and the framing photography. From the experimental results, the very high pressure region including the mach stem was observed in the low velocity explosive, and the overdriven detonation phenomenon was confirmed. The maximum pressure value of the concentric double cylindrical high explosive set up was 2.3 times higher than the Chapman-Jouguet pressure of the single explosive.

scholarly journals A Fluid-Structure Interaction Model of Pressurised Composite Structures Subjected to Blast Loading

2010 ◽  
Vol 19 (3) ◽  
pp. 096369351001900
Author(s):  
G. Mohamed ◽  
C. Soutis ◽  
A. Hodzic
Keyword(s):  
Composite Structures ◽  
Structural Integrity ◽  
Numerical Study ◽  
Fluid Structure Interaction ◽  
Dynamic Crack ◽  
Arbitrary Lagrangian Eulerian ◽  
Fluid Structure ◽  
Explicit Finite Element ◽  
Structure Interaction ◽  
Finite Element Software

A numerical study into the dynamic behaviour of hybrid pressurised barrels manufactured from GLARE (Glass fibre Reinforced laminate) has been performed using the Arbitrary-Lagrangian-Eulerian (ALE) method that accounts for fluid structure interaction within the explicit finite element software RADIOSS. The results high-lighted the importance of the geometrical features of the closed barrel when assessing the shock wave propagation of the blast wave. Also the effect of pre-pressurisation was studied which proved significant in providing additional internal energy to the system. It was concluded that pressurisation should be accounted in all future studies to model the dynamic crack growth and structural integrity of typical aircraft structures subjected to blast.

Numerical study on ice fragmentation by impact based on non-ordinary state-based peridynamics

2019 ◽  
Vol 04 (01) ◽  
pp. 1850006 ◽  
Author(s):  
Ying Song ◽  
Haicheng Yu ◽  
Zhuang Kang
Keyword(s):  
Experimental Data ◽  
Numerical Study ◽  
Plastic Material ◽  
Impact Loads ◽  
Plasticity Model ◽  
Continuous Contact ◽  
Contact Algorithm ◽  
Structure Interaction ◽  
Discontinuous Problems ◽  
Good Agreement

Ice-structure interaction is currently one of the hot topics in engineering fields and has not been addressed. Traditional numerical methods derived from classical continuum mechanics have difficulties in solving such discontinuous problems of ice fragmentations. In the present paper, a non-ordinary state-based peridynamics formulation is presented to simulate the behavior of the ice under impact loads applied by a rigid ball. Ice is assumed as a viscoelastic-plastic material and simulated by the modified Drucker–Prager plasticity model. The failure criterion of ice is defined based on fracture toughness. A continuous contact algorithm is adopted to detect the contact between the rigid ball and ice particles. It is shown that numerical results are in good agreement with experimental data from open-literatures, and the non-ordinary state-based peridynamics model can capture the detail fragmentation features of ice under impact loads.

Transient Simulations of the Fluid–Structure Interaction Response of a Partially Confined Pipe Under Axial Flows in Opposite Directions

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Konstantinos Kontzialis ◽  
Kyriakos Moditis ◽  
Michael P. Païdoussis
Keyword(s):  
Numerical Study ◽  
Critical Value ◽  
Flow Speed ◽  
Physical Parameters ◽  
Structure Interaction ◽  
Transient Simulations ◽  
Flow Induced Vibrations ◽  
The Stability ◽  
Insight Into ◽  
Good Agreement

This paper presents a numerical study of the dynamic response and stability of a partially confined cantilever pipe under simultaneous internal and external axial flows in opposite directions. The onset of flow-induced vibrations is predicted by the developed numerical model, and moreover, limit-cycle motion occurs as the flow speed becomes larger than a critical value. The numerical results are in good agreement with existing experimental results. The simulation gives control over many physical parameters and provides a better insight into the dynamics of the pipe. A parametric study regarding the stability of the system for varying confinement length is performed. The current results show that there is an increase in the susceptibility of the system to instability as the extent of confinement is increased.

Numerical Study on the Interaction of an Inextensible Filament in a Uniform Fluid Flow Using the Immersed Boundary Method

2009 ◽  
Author(s):  
Ranjith Maniyeri ◽  
Yong Kweon Suh ◽  
Sangmo Kang
Keyword(s):  
Fluid Flow ◽  
Immersed Boundary Method ◽  
Numerical Study ◽  
Fluid Structure Interaction ◽  
Immersed Boundary ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Boundary Method ◽  
Good Agreement ◽  
Uniform Fluid

Numerical modeling of fluid-structure interaction problems are challenging in the field of computational fluid dynamics because of the complex geometries involved and freely moving boundaries. Flapping of an inextensible filament in a uniform fluid flow is such a problem which mimics the swimming of energy harvesting eel fish. Recently, immersed boundary method has found much attention in simulating fluid-structure interaction problems due to its easiness in grid generation and memory and CPU savings. In the present work, we employed an improved version of immersed boundary method proposed by Shin et al. [1] which combines the feedback forcing scheme of the virtual boundary method with Peskin’s regularized delta function approach. A FORTRAN code is developed for the simulation of flexible filament flapping in a uniform fluid flow. The code is validated for the bench mark problem of two-dimensional flow over a circular cylinder. A single filament hanging under gravitational force is simulated using the developed code which is analogous to a rope pendulum and the results are compared with available analytical results. The results are found to be in good agreement. Finally, the interaction of the flapping filament in the uniform fluid flow is studied for different flow and structure parameters. The production of a series of vortex procession obtained in the case of flapping of filament is in good agreement with the previous available experimental and numerical results.

Experimental and Numerical Study of Blast-Structure Interaction

2020 ◽  
Author(s):  
Benjamin J. Katko ◽  
Rodrigo Chavez ◽  
Heng Liu ◽  
Barry Lawlor ◽  
Claire McGuire ◽  
...  
Keyword(s):  
Numerical Study ◽  
Structure Interaction

Fluid-Structure Interaction Simulation of the Edge-to-Edge Repair of the Mitral Valve in Functional and Degenerative States

2012 ◽  
Author(s):  
K. D. Lau ◽  
G. Burriesci ◽  
V. Díaz-Zuccarini
Keyword(s):  
Mitral Valve ◽  
Fluid Structure Interaction ◽  
Mitral Valve Regurgitation ◽  
Fluid Structure ◽  
Explicit Finite Element ◽  
Structure Interaction ◽  
Modelling Techniques ◽  
Induced Stresses ◽  
Annular Dilation ◽  
Ventricular Filling

The most common dysfunction of the mitral valve (MV) is mitral valve regurgitation (MVR) which accounts for approximately 70% of native MV dysfunction [1]. During closure, abnormal amounts of retrograde flow enter the left atrium altering ventricular haemodynamics, an issue which can lead to cardiac related pathologies. MVR is caused by a variety of different mechanisms which are either degenerative (myxomatous degeneration) or functional (annular dilation or papillary muscle displacement) [2]. Correction of MVR is performed by repairing existing valve anatomy or replacement with a prosthetic substitute, however repair is preferred as mortality rates are reduced (2.0% against 6.1% for replacement) along with other valve related complications [3]. A common and popular method of repair is the edge-to-edge repair (ETER), which aims to correct MVR by surgically connecting the regurgitant region through reducing the inter-leaflet distance. Although MV function is improved in systole, induced stresses are significantly increased in diastole where the MV is typically in a low state of stress. In order to assess the effect of this technique in diastole, where the dynamics of both the MV and ventricular filling are disrupted it is required to use fluid-structure interaction (FSI) modelling techniques. Here a FSI model of the of the MV has been described, using this model the resulting induced stresses from the ETER in both functional and degenerative states of the MV have been simulated and assessed using the explicit finite element code LS-DYNA.

A numerical study on the influences of underlying soil and backfill characteristics on the dynamic behaviour of typical integral bridges

Bauingenieur ◽  
2020 ◽  
Vol 95 (11) ◽  
pp. S 2-S 11
Author(s):  
H. D. B. Aji ◽  
M. B. Basnet ◽  
Frank Wuttke
Keyword(s):  
Soil Structure ◽  
Dynamic Behaviour ◽  
Numerical Study ◽  
Coupled System ◽  
Soil Structure Interaction ◽  
Dynamic Resistance ◽  
Soil Characteristic ◽  
Structure Interaction ◽  
Integral Bridges ◽  
Underlying Soil

Abstract The identification of the dynamic behaviour of a structure is one of the crucial steps in the design of the dynamic resistance of the structure. The dynamic behaviour is represented by the natural frequencies and damping which are subsequently used along with the considered dynamic actions in the design process. In regard of integral bridge concept, one of the consequences of the omission of joints and bearings is the substantial soil-structure interaction which in turn increases the sensitivity of the dynamic behaviour of the bridges to the surrounding soil characteristic. In this article, we extended our hybrid BEM-FEM steady-state dynamic numerical tool to the 3D regime, developed by utilizing an in-house BEM and the commercial FEM software ABAQUS and use it to analyse the dynamic interaction between the bridge and the underlying soil as well as the backfill. The numerical results from four typical integral bridges show that underlying soil characteristic has great effect on the resonant frequencies and the damping. The backfill material properties tend to have less significant role due to the abutment wingwalls dominating the force transfer between the soil and the superstructure. The results also show that the degree of influence of the soil-structure interaction on the coupled system is affected by the type of load pattern in addition to the flexural stiffness of the superstructure.

Numerical Simulation of Ship Collision and Validations With Experimental Results

2021 ◽  
Author(s):  
Xiangbiao Wang ◽  
Chun Bao Li ◽  
Ling Zhu
Keyword(s):  
Numerical Simulation ◽  
Model Test ◽  
Structural Damage ◽  
Added Mass ◽  
Ship Motion ◽  
Time Dependent ◽  
Structural Deformation ◽  
Structure Interaction ◽  
Ship Collision ◽  
Good Agreement

Abstract Ship collision accidents occur from time to time in recent years, and this would cause serious consequences such as casualties, environmental pollution, loss of cargo on board, damage to the ship and its equipment, etc. Therefore, it is of great significance to study the response of ship motion and the mechanism of structural damage during the collision. In this paper, model experiments and numerical simulation are used to study the ship-ship collision. Firstly, the Coupled Eulerian-Lagrangian (CEL) was used to simulate the fluid-structure interaction for predicting structural deformation and ship motion during the normal ship-ship collision. Meanwhile, a series of model tests were carried out to validate the numerical results. The validation presented that the CEL simulation was in good agreement with the model test. However, the CEL simulation could not present the characteristics the time-dependent added mass.

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