scholarly journals Optimization and Experimental Investigation of the Ability of New Material from Aluminum Casting on Pumice Particles to Reduce Shock Wave

2020 ◽  
Vol 64 (3) ◽  
pp. 224-232
Author(s):  
Masoud Rahmani ◽  
Amin Moslemi Petrudi
Keyword(s):  
Shock Wave ◽  
Static Loading ◽  
Aluminum Foam ◽  
Strain Curve ◽  
Sudden Increase ◽  
Constituent Material ◽  
Smooth Region ◽  
New Material ◽  
Casting Aluminum ◽  
Shock Tube Test

Some materials, due to their inherent properties, can be used as shock and wave absorbers. These materials include foam and porous materials, in this study, specimens were made by casting aluminum on porous mineral pumice. Which can replace aluminum foam in some applications with lesser cost, at first, the material is compared with aluminum foam using compression test and quasi-static loading diagram. Which compares the diagrams of these two materials showing the similarity of their behavior in quasi-static loading. Initially, the elastic bending of the walls causes an elastic region in the stress-strain curve of the material. Then, the plastic collapsing of the cells forms a large and relatively smooth region along the elastic and after the plastic collapse of the cells, the area known as foam densification begins where the density of the foam closer to the density of its constituent material causes a sudden increase in the stress level in the specimen. These steps have also been seen in the quasi-static loading of aluminum foam. Then, by using numerical simulations with ANSYS AUTODYN and the shock tube test the ability of these specimens were investigated to reduce the shock wave. The behavior of the material in this case is also very similar to the results of previous studies on aluminum foam.

scholarly journals Dynamic Compensation of Piezoresistive Pressure Sensor Based on Sparse Domain

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Bo Xu ◽  
Tailin Han ◽  
Hong Liu ◽  
Xiao Wang ◽  
Mingchi Ju
Keyword(s):  
Shock Wave ◽  
Shock Tube ◽  
Test Data ◽  
Pressure Sensor ◽  
Pressure Sensors ◽  
The United States ◽  
Positive Pressure ◽  
Dynamic Compensation ◽  
Tube Test ◽  
Shock Tube Test

In the process of transient test, due to the insufficient bandwidth of the pressure sensor, the test data is inaccurate. Firstly, based on the projection of the shock tube test signal in the sparse domain, the feature expression of the signal sample is obtained. Secondly, the problem of insufficient bandwidth is solved by inverse modeling of sensor dynamic compensation system based on swarm intelligence algorithm. In this paper, the method is used to compensate the shock tube test signals of the 85XX series pressure sensors made by the Endevco company of the United States, the working bandwidth of the sensor is widened obviously, the rise time of the pressure signal can be compensated to 12.5 μs, and the overshoot can be reduced to 8.96%. The repeatability of dynamic compensation is verified for the actual gun muzzle shock wave test data, the results show that the dynamic compensation can effectively recover the important indexes such as overpressure peak value and positive pressure action time, and the original shock wave signal is recovered from the high resonance data.

Shock wave compression behavior of aluminum foam

2003 ◽  
Vol 10 (4) ◽  
pp. 333-337 ◽  
Author(s):  
He-fa Cheng ◽  
Xiao-mei Huang ◽  
Guo-xian Xue ◽  
Fu-sheng Han
Keyword(s):  
Shock Wave ◽  
Aluminum Foam ◽  
Compression Behavior ◽  
Wave Compression ◽  
Shock Wave Compression

scholarly journals Behaviour of the peach under underwater shock wave loading

2008 ◽  
Vol 56 (4) ◽  
pp. 151-160
Author(s):  
Libor Severa
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Strain Rate ◽  
Compression Test ◽  
Static Loading ◽  
Surface Velocity ◽  
Shock Wave Loading ◽  
Wave Loading ◽  
Underwater Shock Wave ◽  
Underwater Shock

The paper concerns with the experimental and numerical study of the peach (Red Haven) at underwater shock wave loading. The behaviour of the peach skin as well as peach stone can be described in terms of elasticity. Following experiments have been performed: tensile testing of the skin (exocarp) specimens at constant elongation at strain rate 0.01 s−1, compression test of the mesocarp specimens at different strain rates corresponding to quasi – static loading, compression test of the mesocarp spe­ci­mens at the high rates of strain (about 1000 s−1), and compression test of the whole peach stone at strain rate corresponding to quasi – static loading. The model of the peach has been suggested. The model is used for the numerical simulation, which was performed on the software LS DYNA 3D finite element code. Pressure wave propagation in the water has been studied and following quantities evaluated: pressure on the peach surface, displacement, and surface velocity. Two different models (Maxwell and Kelvin) have been used. The results of this simulation show some agreement with results of the observation (undamaged peach skin). The numerical simulation also gives an insight on the details of the loading, which was recently tested as a tool of fruit treatment. It has been shown that undewater shock wave treatment of peaches can lead to their softening.

scholarly journals Experimental and numerical optimization study of shock wave damping in aluminum panel sandwich

2020 ◽  
Vol 15 (55) ◽  
pp. 88-109
Author(s):  
Masoud Rahmani ◽  
Amin Moslemi Petrudi
Keyword(s):  
Shock Wave ◽  
Numerical Optimization ◽  
Aluminum Foam ◽  
Experimental Testing ◽  
Weight Ratio ◽  
High Strength ◽  
Shock Propagation ◽  
Wave Damping ◽  
Optimization Study ◽  
Porous Grains

Sandwich panels with polymer composite and light core composites are widely used in aircraft and spacecraft, vessels, trains, submarines, and cars. Due to their high strength to weight ratio, high stability, and high corrosion resistance, these structures have become particularly important in the industry. Reduction in impact energy, shock waves, and noise in many industries, including the automotive and military industries. Porous materials have always been the focus of attention due to their shock-reducing effects in various protective applications. For this reason, the study of physics governing shock propagation problems in porous media is of particular importance, and the complexity of the governing equations also results in the numerical solution of these equations with many computational problems and costs. In this paper, shock wave damping is investigated numerically and experimentally in aluminum blocks with porous grains scattered inside aluminum. The deformations of the specimens in numerical simulation and experimental testing have been compared. The results show that this material behaves similarly to the aluminum foam in both static loadings (practical pressure testing) and dynamic loading (explosion simulation) results, again similar to aluminum foam.

Rate-Dependent Constitutive Model Coupled with Temperature Softening for Open-Cell Aluminum Foam

2013 ◽  
Vol 470 ◽  
pp. 70-75
Author(s):  
Wei Zheng ◽  
Bao Jun Pang ◽  
Yong Chen
Keyword(s):  
Constitutive Model ◽  
Dynamic Loading ◽  
Aluminum Foam ◽  
Split Hopkinson Pressure Bar ◽  
Strain Curve ◽  
Hopkinson Pressure Bar ◽  
Element Analysis ◽  
Open Cell ◽  
Rate Dependent ◽  
Loading Tests

Both quasi-static compressive tests and dynamic loading tests on the open-cell aluminum foam made of 6061 aluminum alloy were firstly conducted. The Split Hopkinson Pressure Bar (SHPB) apparatus was used to perform the dynamic loading tests. The rate-dependent constitutive model for the open-cell aluminum foam was then studied. Based on the empirical constitutive model proposed by Sherwood for polyurethane foam, a new function was found to analyze the three-stage characteristic of quasi-static stress-strain curve of the aluminum foam. Moreover, the temperature softening was also modified. Thus a new strain rate hardening constitutive model coupled with temperature softening for the open-cell aluminum foam was obtained. Finally, both Taylor impact tests and finite element analysis (FEA) were conducted to verify the new constitutive model and the results show that the model was reliable.

Fullerene stability under shock-wave and static loading

1994 ◽  
Vol 30 (2) ◽  
pp. 259-260
Author(s):  
O. G. Epanchintsev ◽  
A. A. Dityat'ev
Keyword(s):  
Shock Wave ◽  
Static Loading ◽  
Fullerene Stability

scholarly journals Non-Oscillatory Finite Compact Scheme for the Equations of Ideal Magnetohydrodynamics

2013 ◽  
Vol 432 ◽  
pp. 157-162
Author(s):  
Li Liu ◽  
Yi Qing Shen
Keyword(s):  
Shock Wave ◽  
Mhd Equations ◽  
Compact Scheme ◽  
Internal Boundary ◽  
Computational Domain ◽  
Smooth Region ◽  
Wave Region ◽  
Ideal Magnetohydrodynamics ◽  
Detecting Method ◽  
Hydrodynamics Equations

Although the equations of ideal Magnetohydrodynamics (MHD) is a non-strictly hyperbolic system, they have a wave-like structure analogous to that of the hydrodynamics equations, various numerical schemes for hydrodynamics equations have been extended to solve the MHD equations. The finite compact (FC) scheme treats the discontinuity as the internal boundary and avoids the global dependence of the traditional compact schemes. By using a parameter-free shock detecting method, the computational domain is divided into a series of smooth regions and shock wave regions. In the shock wave regions, the shock capturing scheme is used to construct the numerical flux, and in the smooth regions the compact scheme is used, the flux of shock wave region is automatically the boundary formulation of the compact scheme. Hence, the FC scheme can resolve shock essentially non-oscillatory and achieve high order of accuracy in smooth region. This paper develops the non-oscillation finite compact scheme for the ideal MHD equations.

scholarly journals Shock Wave Attenuation Characteristics of Aluminum Foam Sandwich Panels Subjected to Blast Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jinglin Xu ◽  
Jianqing Liu ◽  
Wenbin Gu ◽  
Xin Liu ◽  
Tao Cao
Keyword(s):  
Shock Wave ◽  
Mild Steel ◽  
Polyvinylidene Fluoride ◽  
Sandwich Structure ◽  
Aluminum Foam ◽  
Wave Attenuation ◽  
Steel Structure ◽  
Steel Structures ◽  
Test Results ◽  
Attenuation Rate

Comparative experiments were conducted with two different structures to study the mechanism of aluminum foam sandwich attenuating blast shock wave. The sandwich structure is composed of “steel–aluminum foam–steel,” and the mild steel structure is composed of “steel–steel.” In the experiment, the polyvinylidene fluoride transducers were used to directly test the load of stress wave between different interfaces of sandwich and mild steel structures. The strain of back sheet was simultaneously measured using high-precision strain gauge. The accuracy of the test results was verified by Henrych’s formula. Experimental results show that the wave attenuation rate on the mild steel structure is only 11.3%, whereas the wave attenuation rate on the sandwich structure can exceed 90%. The interface effect is clearly a more crucial factor in the wave attenuation. The peak value of back sheet strain in the mild steel structure is much higher than the sandwich structure. The apparent overall “X” crushing band is produced in the aluminum foam core, and scanning electron microscope (SEM) observation clearly shows the collapse of the cell wall. Experiments on the sandwich structure with different aluminum foam densities indicate that increasing the relative density results in increased attenuation capability of the aluminum foam and decreased attenuation capability of the sandwich structure. Experiments on the sandwich structure with different aluminum foam thickness indicate that increasing the thickness results in increased attenuation capability of the aluminum foam and the sandwich structure.

Shock Enhancement of Aluminum Foam under Impact Loading Using FEM Simulations

2010 ◽  
Vol 160-162 ◽  
pp. 1077-1082 ◽  
Author(s):  
Xin Mei Xiang ◽  
Yu Long Li ◽  
Tao Suo ◽  
Bing Hou
Keyword(s):  
Shock Wave ◽  
Relative Density ◽  
Impact Velocity ◽  
Wave Velocity ◽  
Impact Loading ◽  
Aluminum Foam ◽  
Shock Wave Velocity ◽  
Sample Length ◽  
Fem Simulations ◽  
The Impact

The compressive behaviors of aluminum foam under impact loading are investigated using FEM simulations. The plastic deformation takes place locally and an enhancement of force occurs at the impact end of the samples. By further investigation, this shock enhancement is found decreasing with relative density, but increasing with impact velocity. We also estimate the shock wave velocity. It is found that shock wave velocity increases significantly with impact velocity, but changes slightly with relative density. It is noted that the influence of the sample length on both the shock enhancement and the shock wave velocity is negligible. Finally, the relations of shock enhancement and shock wave velocity with impact velocity are obtained.

Numerical Study on the Mechanical Behavior of Aluminum Foam Material Using CT Image

2009 ◽  
Vol 79-82 ◽  
pp. 1297-1300 ◽  
Author(s):  
Hyup Jae Chung ◽  
Kyong Yop Rhee ◽  
Beom Suck Han ◽  
Yong Mun Ryu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Aluminum Foam ◽  
Three Dimensional ◽  
Strain Curve ◽  
Foam Material ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Element Analysis ◽  
X Ray

In this study, finite element analysis was made to predict the tensile and compressive behaviors of aluminum foam material. The predicted tensile and compressive behaviors were compared with those determined from the tensile and compressive tests. X-ray imaging technique was used to determine internal structure of aluminum foam material. That is, X-ray computed tomography (CT) was used to model the porosities of the material. Three-dimensional finite element modeling was made by stacking two-dimensional tomography of aluminum foam material determined from CT images. The stackings of CT images were processed by three-dimensional modeling program. The results showed that the tensile stress-strain curve predicted from the finite element analysis was similar to that determined by the experiment. The simulated compressive stress-strain curve also showed similar tendency with that of experiment up to about 0.4 strain but exhibited a different behavior from the experimental one after 0.4 strain. The discrepancy of compressive stress-strain curves in a high strain range was associated with the contact of aluminum foam walls broken by the large deformation.

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