Experiment on the Attenuation Characteristics of Shock Wave Interacting with Open and Closed Foam

2014 ◽  
Vol 1035 ◽  
pp. 445-452
Author(s):  
Jian Wang ◽  
Bao Gui Wang ◽  
Gang Tao
Keyword(s):  
Shock Wave ◽  
Internal Friction ◽  
Dynamic Behavior ◽  
Solid Phase ◽  
Experimental Results ◽  
Reflection And Transmission ◽  
Attenuation Characteristics

For understanding the dynamic behavior of open and closed foam subject to a shock wave, this paper through experiments, to gain a deeper understanding of the incidence, reflection and transmission of a shock wave when it interacted with cellular foam. Moreover, by analyzing the loss of the peak overpressure and positive impulse, we were able to respectively know the positive impulse of the incidence, reflection and transmission shock wave. The experimental results indicated that the attenuation capability for foam to the shock wave was caused by the internal friction and deformation of solid phase, which would absorb the energy of the shock wave. From the results we gain an understanding that the mechanical phenomenon of open foam to shock wave are not fully consistent with those of closed foam , while the attenuation of open foam to shock wave is more effective than that of closed foam.

The Mechanical Properties for the Attenuation of Shock Wave Interaction with Watery Foam Material

2013 ◽  
Vol 815 ◽  
pp. 558-566 ◽  
Author(s):  
Jie Zhou ◽  
Gang Tao
Keyword(s):  
Mechanical Properties ◽  
Shock Wave ◽  
Internal Friction ◽  
Dynamic Behavior ◽  
Wave Interaction ◽  
Experimental Results ◽  
Foam Material ◽  
Reflection And Transmission ◽  
Shock Wave Interaction ◽  
Water Atomization

For understanding the dynamic behavior of watery cellular foam subject to a shock wave, this paper through experiments, to gain a deeper understanding of the incidence, reflection and transmission of a shock wave when it interacted with watery foam. Moreover, by analyzing the loss of the peak overpressure and positive impulse, we were able to respectively know the positive impulse of the incidence, reflection and transmission shock wave. The experimental results indicated that the attenuation capability for watery foam to the shock wave was caused by the internal friction and the water atomization, which would absorb the energy of the shock wave. Therein, the higher percentage of water in the cellular foam, the more obvious attenuation phenomenon for the shock wave was presented. However, the mechanical processes of cellular foam with different water percentages subject to the shock wave were not completely consistent.

Dependence of the Dynamic Behavior of Supersaturated Silicic Acid on the Surface Area of the Solid Phase

2008 ◽  
Author(s):  
Yuichi Niibori ◽  
Yasunori Kasuga ◽  
Hiroshi Kokubun ◽  
Kazuki Iijima ◽  
Hitoshi Mimura
Keyword(s):  
Surface Area ◽  
Dynamic Behavior ◽  
Silicic Acid ◽  
Solid Phase

Metallographic Estimation of the Number of Forming Metallic Particles Obtained during Direct and Indirect Reduction of Metals from Complex Oxides

2019 ◽  
Vol 946 ◽  
pp. 523-527
Author(s):  
Arman S. Bilgenov ◽  
P.A. Gamov ◽  
V.E. Roshchin
Keyword(s):  
Metal Forming ◽  
Solid Phase ◽  
Quantitative Estimation ◽  
Direct Reduction ◽  
Reduction Process ◽  
Complex Oxide ◽  
Experimental Results ◽  
Solid Carbon ◽  
Indirect Reduction ◽  
Co Gas

The direct reduction of metals from a complex oxide with low iron content by solid carbon and indirect reduction by CO gas were studied in a vertical laboratory resistance furnace at 1300 °C for an hour reduction time. The experimental results were described from the point of view of the electrochemical nature of the metal reduction process, that involves the interaction of ions and electrons in the oxide lattice. The technique was developed by using the two different software programs for the quantitative estimation of the areas, average size and number of the metal forming in a complex oxide with extensive fields of vision. The obtained results of the quantitative characteristics of the metal forming during solid-phase carbo-thermal reduction were presented. The processes of reduction by solid carbon and CO gas based on the areas occupied by metal particles were quantitatively compared. The experimental results and the prospects for further experimental work were assessed and outlined.

Effect of Biphase Lubricants on Dynamics of Rigid Rotors

1983 ◽  
Vol 105 (1) ◽  
pp. 29-38 ◽  
Author(s):  
A. Mukherjee
Keyword(s):  
Bearing Capacity ◽  
Dynamic Behavior ◽  
Solid Phase ◽  
Qualitative Change ◽  
Surface Velocity ◽  
Medium Size ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Rotational Load ◽  
Rigid Rotors

The dynamic behavior of rigid rotors as affected by the use of liquid-solid biphase lubricants in the supporting hydrodynamic bearings is studied theoretically. Two categories of dynamic behavior viz (a) unbalance response at low rotor speeds, and (b) half frequency whirl at high speeds, are studied. It is shown that the use of liquid-solid biphase lubricants causes considerable reduction in the size of journal orbit of an unbalanced rotor. The influence of particle size and dispersion concentration is studied. It is observed that an early reversal of journal surface velocity in the trailing half of crushing zone reduces the efficacy of the crushing action of the solid phase to some extent and results in periodic pulses applied by the solid phase on the journal. At higher journal speeds at which the operating point of the journal becomes unstable and the phenomenon of half-frequency whirl sets in, the use of biphase lubricants with small and medium-size particles causes a reduction in the size of whirl orbits. The journal, however, keeps whirling in a manner such that the whirl ratio crosses the value of + 1/2 twice in an orbit and thus the bearing loses its rotational load bearing capacity twice in an orbit. The use of large particles with heavy or medium weight rotors results in a significant qualitative change in the nature of whirl orbit. The journal center in such cases does not encircle the bearing center and the whirl ratio of + 1/2 is never reached. The liquid phase retains rotational load bearing capacity and shares the major part of rotor weight throughout.

Internal friction and Mössbauer study of C–Cr associates in MANET steel

1997 ◽  
Vol 12 (2) ◽  
pp. 296-299 ◽  
Author(s):  
P. Gondi ◽  
R. Gupta ◽  
R. Montanari ◽  
G. Principi ◽  
M. E. Tata
Keyword(s):  
Internal Friction ◽  
Slow Rate ◽  
Structural Model ◽  
Martensitic Steel ◽  
Experimental Results ◽  
Thermal Treatments ◽  
Mössbauer Study ◽  
Low Intensity ◽  
Magnetic Pattern ◽  
Bcc Phase

Internal friction and Mössbauer techniques have been used to investigate the structure of C–Cr associates and the arrangement of Fe atoms near them in the Cr martensitic steel MANET subjected to different thermal treatments. After slow rate cooling from the austenitic field, the Mössbauer spectra exhibit, besides the complex magnetic pattern of martensite, a low intensity singlet attributed to the presence of a Cr-rich bcc phase. In correspondence, the internal friction curves, show, among others, a Snoek-type peak due to anelastic processes involving C–Cr associates with 6 Cr atoms. To explain the experimental results, a simple structural model is suggested.

Experimental and Analytical Investigation on Spaghetti Problem

2001 ◽  
Author(s):  
Yoshimasa Komaki ◽  
Nobuyuki Kobayashi ◽  
Masahiro Watanabe
Keyword(s):  
Dynamic Behavior ◽  
Multibody Dynamics ◽  
Constant Velocity ◽  
Analytical Investigation ◽  
Experimental Results ◽  
Flexible Beam ◽  
Gap Size ◽  
Lateral Vibration ◽  
Elastic Wall ◽  
Pulling Velocity

Abstract The dynamic behavior of the flexible beam, which is pulled into the slit of the elastic wall with a constant velocity, is discussed with multibody dynamics formulation and experiments. The vibration of the free tip of a flexible beam increases rapidly as pulling into the slit, and this behavior is called “Spaghetti Problem”. The effect of gap size of the slit on the behavior of Spaghetti Problem is especially focused. Dynamic behavior of the beam is simulated numerically and examined the accuracy of the presented formulation by changing the gap size and the pulling velocity of the beam as parameters. It is clarified that the presented modeling method simulates the experimental results quite well, and the gap size and the pulling velocity influence the increase of the lateral vibration near the inlet of the slit.

scholarly journals Surface Plasmon Singularities

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Gabriel Martínez-Niconoff ◽  
P. Martinez-Vara ◽  
G. Diaz-Gonzalez ◽  
J. Silva-Barranco ◽  
A. Carbajal-Domínguez
Keyword(s):  
Shock Wave ◽  
Boundary Condition ◽  
Electromagnetic Field ◽  
Metal Surface ◽  
Surface Plasmon ◽  
Computer Simulations ◽  
Free Space ◽  
Experimental Results ◽  
Physical Features

With the purpose to compare the physical features of the electromagnetic field, we describe the synthesis of optical singularities propagating in the free space and on a metal surface. In both cases the electromagnetic field has a slit-shaped curve as a boundary condition, and the singularities correspond to a shock wave that is a consequence of the curvature of the slit curve. As prototypes, we generate singularities that correspond to fold and cusped regions. We show that singularities in free space may generate bifurcation effects while plasmon fields do not generate these kinds of effects. Experimental results for free-space propagation are presented and for surface plasmon fields, computer simulations are shown.

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