A Numerical Study on Jet Formation and Penetration Characteristics of the Shaped Charge with an Aspect Ratio of 2.73 and a High-Strength Copper Liner

2019 ◽  
Vol 24 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Dong-Hoo Kim ◽  
Hyunho Shin ◽  
Dong-Wol Jung ◽  
Eun-Ho Lee ◽  
Seung-Jae Seo ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Numerical Study ◽  
High Strength ◽  
Shaped Charge ◽  
Jet Formation

scholarly journals High strength steel cold-formed hollow sections: implication of cross-section aspect ratio and slenderness characteristics on flexural behavior

2019 ◽  
Author(s):  
Shady Adib ◽  
Ieva Misiunaite
Keyword(s):  
Aspect Ratio ◽  
Cross Section ◽  
Numerical Study ◽  
Plastic Material ◽  
High Strength ◽  
Flexural Behavior ◽  
Design Codes ◽  
Structural Problems ◽  
Tubular Sections ◽  
Structural Solutions

Cold-formed tubular sections are widely applicated for a variety of structural solutions, primarily due to their advantageous structural properties, inherent aesthetic characteristics and ease of prefabrication and mass production. High strength steels (HSS) are attaining growing attention from structural engineers and researchers due to their potential on the design of lightweight and more economic structures. In combination with cold-formed tubular sections HSS might serve as improvement on structural efficiency as well as solution for structural problems when usage of normal steel is limited due to insufficient strength. However, innovative structural solutions are often faced problems related with absence of appropriate design procedures. In most of the design codes cross-section design is performed following the traditional classification procedure based on the slenderness of the individual constituents without respect to their interaction. Moreover, tubular sections are generally treated in the same manner without respect to their formation route, embedding an elastic-perfectly plastic material model, without reference to the cold-formed sections increased strength and reduced ductility over the flat material. This paper reports on the numerical study of cold-formed HSS tubular beams deformation response, with a focus on the effect of cross-section constituent’s interaction and strength enhancement influence on the cross-section slenderness. Finite element (FE) models were first developed and validated against existing test results. Upon validation against the experimental results, parametric studies were carried out to expand the available flexural response data over a range of cross-section aspect ratio, cross-section slenderness and steel grades. The obtained numerical results were used to assess the suitability of the current design codes cross-sections classification for cold-formed HSS tubular beams.

scholarly journals Experimental and Numerical Study on the PG-7VM Warhead Performance against High-Hardness Armor Steel

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3020
Author(s):  
Paweł Żochowski ◽  
Radosław Warchoł ◽  
Maciej Miszczak ◽  
Marcin Nita ◽  
Zygmunt Pankowski ◽  
...  
Keyword(s):  
Numerical Model ◽  
Numerical Study ◽  
High Hardness ◽  
The Body ◽  
Shaped Charge ◽  
Steel Plates ◽  
Technical Documentation ◽  
Jet Formation ◽  
Depth Of Penetration ◽  
Shaped Charge Jet

Analyses presented in the article were carried out in order to characterize the main parameters of the shaped charge jet formed due to detonation of the PG-7VM warhead. As opposed to the previously published studies in which rolled homogeneous armored steel was mainly used as a target, in the current work the warhead penetration capability was determined against more contemporary high-hardness (500 HB) ARMSTAL 30PM steel armor with precisely determined mechanical properties. The research included experimental depth of penetration tests and their numerical reproduction in the LS-Dyna software. Special attention was paid to factors that could perturbate the shaped charge jet formation process and under- or overestimate its penetration capability. For this reason, warheads were X-ray inspected for structural discrepancies (voids or air inclusions in explosive, misalignment between the body, explosive, and liner, or lack of contact between the explosive and the liner) and properties of materials (explosive, targets, and most important warhead components) were analyzed before the experiments. The numerical model of the warhead was defined more accurately than in previously published studies, since it was based on the real grenade dimensions and its technical documentation. Thanks to this, the depth of penetration of the target made of ARMSTAL 30PM armored steel plates by the shaped charge jet formed from the PG-7VM warhead obtained by numerical simulation was consistent with the experimental results and equaled 278 mm and 280 mm, respectively. The difference between the experimental and numerical value was smaller than 1%, which confirms that the developed methodology of modeling allows users to properly reproduce the PG-7VM shaped charge jet formation and target penetration processes. A verified numerical model of the shaped charge jet penetration into a steel target was used to determine depth of penetration in function of stand-off distance for the PG-7VM warhead. A maximum depth of penetration of about 317 mm was obtained for the stand-off distance of 360 mm, which may indicate the potential direction of modernization of warheads.

Numerical Study of Shaped Charge Jet Formation and Penetration into Multi-Layer with Different Liner Material

2010 ◽  
Vol 148-149 ◽  
pp. 744-748 ◽  
Author(s):  
Yan Long Kang ◽  
Jian Wei Jiang ◽  
Shu You Wang ◽  
Jian Bing Men
Keyword(s):  
Titanium Alloy ◽  
Mild Steel ◽  
Numerical Study ◽  
Hole Diameter ◽  
Shaped Charge ◽  
Jet Formation ◽  
Liner Material ◽  
Shaped Charge Jet ◽  
Tip Velocity ◽  
Good Agreement

This paper investigates the penetration performance of shaped charge against multi-layer target. A titanium alloy liner of shaped charge is proposed in order to obtain large perforated hole. Jet formation and penetrating into multi-layer target was calculated by hydro code AUTODYN. For different liner material include titanium alloy, mild steel and Cu, the explosion energy conversion, jet tip velocity and jet length, also the penetration performance are studied. It is found that the kinetic energy of jet is larger and the shape of jet is podgier when the liner material is titanium alloy, the perforated hole diameter on multi-layer improved 20% compare with the mild steel and Cu liner, the numerical simulation is good agreement to experimental results.

scholarly journals Numerical Study on the Surface Plasmon Resonance Tunability of Spherical and Non-Spherical Core-Shell Dimer Nanostructures

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1728
Author(s):  
Joshua Fernandes ◽  
Sangmo Kang
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Surface Plasmon Resonance ◽  
Aspect Ratio ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Shell Thickness ◽  
Numerical Study ◽  
Field Enhancement ◽  
Core Shell

The near-field enhancement and localized surface plasmon resonance (LSPR) on the core-shell noble metal nanostructure surfaces are widely studied for various biomedical applications. However, the study of the optical properties of new plasmonic non-spherical nanostructures is less explored. This numerical study quantifies the optical properties of spherical and non-spherical (prolate and oblate) dimer nanostructures by introducing finite element modelling in COMSOL Multiphysics. The surface plasmon resonance peaks of gold nanostructures should be understood and controlled for use in biological applications such as photothermal therapy and drug delivery. In this study, we find that non-spherical prolate and oblate gold dimers give excellent tunability in a wide range of biological windows. The electromagnetic field enhancement and surface plasmon resonance peak can be tuned by varying the aspect ratio of non-spherical nanostructures, the refractive index of the surrounding medium, shell thickness, and the distance of separation between nanostructures. The absorption spectra exhibit considerably greater dependency on the aspect ratio and refractive index than the shell thickness and separation distance. These results may be essential for applying the spherical and non-spherical nanostructures to various absorption-based applications.

Heat transfer characteristics of nanofluids from a sinusoidal corrugated cylinder placed in a square cavity

2021 ◽  
pp. 095440622110272
Author(s):  
Salaika Parvin ◽  
Nepal Chandra Roy ◽  
Litan Kumar Saha ◽  
Sadia Siddiqa
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Rayleigh Number ◽  
Aspect Ratio ◽  
Average Nusselt Number ◽  
Numerical Study ◽  
Heat Transfer Characteristics ◽  
Number Range ◽  
Transfer Characteristics ◽  
Wide Range

A numerical study is performed to investigate nanofluids' flow field and heat transfer characteristics between the domain bounded by a square and a wavy cylinder. The left and right walls of the cavity are at constant low temperature while its other adjacent walls are insulated. The convective phenomena take place due to the higher temperature of the inner corrugated surface. Super elliptic functions are used to transform the governing equations of the classical rectangular enclosure into a system of equations valid for concentric cylinders. The resulting equations are solved iteratively with the implicit finite difference method. Parametric results are presented in terms of streamlines, isotherms, local and average Nusselt numbers for a wide range of scaled parameters such as nanoparticles concentration, Rayleigh number, and aspect ratio. Several correlations have been deduced at the inner and outer surface of the cylinders for the average Nusselt number, which gives a good agreement when compared against the numerical results. The strength of the streamlines increases significantly due to an increase in the aspect ratio of the inner cylinder and the Rayleigh number. As the concentration of nanoparticles increases, the average Nusselt number at the internal and external cylinders becomes stronger. In addition, the average Nusselt number for the entire Rayleigh number range gets enhanced when plotted against the volume fraction of the nanofluid.

NUMERICAL AND EXPERIMENTAL STUDY ON FREE VIBRATION OF DELAMINATED WOVEN FIBER GLASS/EPOXY COMPOSITE PLATES

2012 ◽  
Vol 12 (02) ◽  
pp. 377-394 ◽  
Author(s):  
J. MOHANTY ◽  
S. K. SAHU ◽  
P. K. PARHI
Keyword(s):  
Experimental Study ◽  
Aspect Ratio ◽  
Free Vibration ◽  
Boundary Conditions ◽  
Natural Frequencies ◽  
Numerical Study ◽  
Shear Deformation Theory ◽  
Composite Plates ◽  
Fiber Glass ◽  
Number Of Layers

This paper presents a combined experimental and numerical study of free vibration of industry-driven woven fiber glass/epoxy (G/E) composite plates with delamination. Using the first-order shear deformation theory, an eight-noded two-dimensional quadratic isoparametric element was developed, which has five degrees of freedom per node. In the experimental study, the influence of various parameters such as the delamination size, boundary conditions, fiber orientations, number of layers, and aspect ratio on the natural frequencies of delaminated composite plates are investigated. Comparison of the numerical results with experimental ones shows good agreement. Fundamental natural frequencies are found to decrease with the increase in the delamination size and fiber orientation and increases with the increase in the number of layers and aspect ratio of delaminated composite plates. The natural frequency of the delaminated composite plate varies significantly for different boundary conditions.

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