scholarly journals Ultrasonic Detection of Spall Damage Distribution Subjected to Plate Impact Test with Different Thickness

2018 ◽  
Vol 183 ◽  
pp. 02029
Author(s):  
Naoya Nishimura ◽  
Toshihiro Ito ◽  
Takeru Watanabe
Keyword(s):  
Tensile Stress ◽  
Impact Test ◽  
Plate Thickness ◽  
Flyer Plate ◽  
Plate Impact ◽  
Target Plate ◽  
Damage Distribution ◽  
Spall Damage ◽  
The Impact ◽  
Different Thickness

Plate impact test on medium carbon steel were carried out to the target plate by impacting the flyer plate with one-third and two-thirds thickness of the target plate. The spall damage within the target plate was evaluated non-destructively with a low frequency scanning acoustic microscope as well as ultrasonic velocity and backscattering intensity. We observed the spall damage distribution by the B-and Cscan images. The distribution of spall damage through the plate thickness depends on the tensile stress area within the target plate. The difference of spall damage distribution was investigated by the plate impact test by flyer plate with different thickness. In the plate impact test by the flyer plate with 1/3 target plate thickness, the spall damage was generated by tensile stress area which superposed in the back surface side. On the other hand, in the case of 2/3 target plate thickness, the spall damage was detected at the impact surface side. By generating the spall damage in the different position through the target thickness, it will be possible to evaluate the accumulation of spall damage by reflection and transmission of the stress wave at the internal damage subjected to repeated impact.

The Numerical Simulation of behind Armor Debris by Shaped Charge Jet Penetration

2014 ◽  
Vol 951 ◽  
pp. 257-260
Author(s):  
Bo Liu ◽  
Zhi Min Yao ◽  
Guo Qing Liu
Keyword(s):  
Plate Thickness ◽  
Emission Angle ◽  
Shaped Charge ◽  
Target Plate ◽  
Whole Process ◽  
Armor Plate ◽  
Axis Of Symmetry ◽  
Sph Algorithm ◽  
Shaped Charge Jet ◽  
Different Thickness

In order to study the aftereffect of the target plate penetrated by shaped charge jet , with the help of nonlinear dynamics solver AUTODYN, the SPH algorithm was adopted to simulate the whole process of jet penetrating the armor plate with different thickness under the condition of vertical. Results show that while the jet head perforating the plate, the behind armor debris (DAB) cloud will be formed, and the axis of symmetry of the "ellipsoid" is the jet direction. However, with the increase of target plate thickness, the behind armor debris number reduced, largest fragment emission angle also reduced.

Multi-Thickness Target Plate Impact Experimental Approach to Failure Waves in Soda-lime Glass and Its Numerical Simulation

2012 ◽  
Vol 13 (1) ◽  
Author(s):  
Zhuo-Ping Duan ◽  
Yan-Geng Zhang ◽  
Lian-Sheng Zhang ◽  
Zhuo-Cheng Ou ◽  
Feng-Lei Huang
Keyword(s):  
Numerical Simulation ◽  
Experimental Period ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Plate Impact ◽  
Target Plate ◽  
Failure Wave ◽  
Applied Software ◽  
Surface Particle ◽  
The Impact

AbstractA multi-thickness target plate impact experimental technique is proposed in this paper and adopted in the research on the so-called failure wave phenomenon in soda-lime glasses, in which, four sub-targets in different thicknesses embedded in the target ring are impacted simultaneously and the longitudinal stress temporal curves at the backing surface of each of the sub-targets are measured by four manganin piezo-resistive stress sensors. Hence, the failure wave trajectory under a certain dynamic loading can be obtained by only one test, which can reduce considerably the experimental expense as well as the experimental period, and, more importantly, the measurement uncertainty resulted from different loading conditions in repetitious impact experiments is avoided. It is found that the propagating velocity of failure wave is approximate to a constant and increases with the magnitude of the impact loading, and there always exists an initial delay time for the initiation of failure wave behind the precursory shock wave, which decreases with the magnitude of impact loads. Moreover, a numerical simulation for the failure wave propagation is carried out by using the LS-DYNA applied software, together with a statistical isotropic elastic microcrack model to describe the dynamic damage evolvement of soda-lime glasses. It is demonstrated that both the critical damage value distributions and the free surface particle velocity temporal curves can be used to determine the failure wave trajectory, and the numerical results are consistent substantially with the experimental data.

Failure Behaviour of Sandwich Beam Subjected to Projectile Impact

2011 ◽  
Vol 183-185 ◽  
pp. 2143-2147
Author(s):  
Li Qing Meng ◽  
Shi Zhe Chen ◽  
Yan Wu ◽  
Xue Feng Shu
Keyword(s):  
Impact Test ◽  
Sandwich Beam ◽  
Damage Mechanism ◽  
Honeycomb Core ◽  
Failure Behaviour ◽  
Core Damage ◽  
Nomex Honeycomb ◽  
The Difference ◽  
The Impact ◽  
Different Thickness

Aerodynamic gun impact test is carried out to investigate sandwich beam with metallic skin and Nomex honeycomb core damage mechanism and failure behaviour. Details of the deformation and damage progression within the sandwich beam are observed in particular. The comparisons between the two kinds of specimen with different thickness skins clearly show that the difference in the impact energy consumed in global bending deformation and the localized indentation. Theoretical elastic bending stiffness of the sandwich beam with thicker skins is approximately 2.26 times greater than that of sandwich beam with thinner skins.

Multi-Thickness Target Plate Impact Experimental Approach to Failure Waves in Soda-lime Glass and Its Numerical Simulation

2012 ◽  
Vol 13 (1) ◽  
Author(s):  
Zhuo-Ping Duan ◽  
Yan-Geng Zhang ◽  
Lian-Sheng Zhang ◽  
Zhuo-Cheng Ou ◽  
Feng-Lei Huang
Keyword(s):  
Numerical Simulation ◽  
Experimental Period ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Plate Impact ◽  
Target Plate ◽  
Failure Wave ◽  
Applied Software ◽  
Surface Particle ◽  
The Impact

AbstractA multi-thickness target plate impact experimental technique is proposed in this paper and adopted in the research on the so-called failure wave phenomenon in soda-lime glasses, in which, four sub-targets in different thicknesses embedded in the target ring are impacted simultaneously and the longitudinal stress temporal curves at the backing surface of each of the sub-targets are measured by four manganin piezo-resistive stress sensors. Hence, the failure wave trajectory under a certain dynamic loading can be obtained by only one test, which can reduce considerably the experimental expense as well as the experimental period, and, more importantly, the measurement uncertainty resulted from different loading conditions in repetitious impact experiments is avoided. It is found that the propagating velocity of failure wave is approximate to a constant and increases with the magnitude of the impact loading, and there always exists an initial delay time for the initiation of failure wave behind the precursory shock wave, which decreases with the magnitude of impact loads. Moreover, a numerical simulation for the failure wave propagation is carried out by using the LS-DYNA applied software, together with a statistical isotropic elastic microcrack model to describe the dynamic damage evolvement of soda-lime glasses. It is demonstrated that both the critical damage value distributions and the free surface particle velocity temporal curves can be used to determine the failure wave trajectory, and the numerical results are consistent substantially with the experimental data.

Effects of spinning on residual velocity of ogive-nosed projectile undergoing ordnance velocity impact

2021 ◽  
pp. 095440622110200
Author(s):  
V Pranay ◽  
SK Panigrahi
Keyword(s):  
Plate Thickness ◽  
Tungsten Alloy ◽  
Target Plate ◽  
Residual Velocity ◽  
Element Analysis ◽  
Velocity Impact ◽  
Nose Shape ◽  
Ansys Explicit Dynamics ◽  
Rigorous Error ◽  
The Impact

In the present article, finite element analysis (FEA) based simulation on the study of the impact of projectiles having ogive nose shape has been made using ANSYS explicit dynamics. The effects of spinning on the residual velocity of ogive nosed projectile undergoing ordnance velocity impact have been presented. The variations of residual velocity due to different projectile materials and target plate thickness have been evaluated when the projectile is impacted by translational and spinning velocity. The target plates and ogive nosed projectile of a given material are discretized, and a rigorous error and convergence study has been made. Subsequently, the residual velocity of the considered model is evaluated by numerical techniques based on FEA. The results with the optimized meshed model are compared with the analytical results using the penetration theory and found that the results are well compared. Parametric study of the residual velocity has been made with varied ogive nosed materials and target plate thickness when the ogive nosed projectile undergoing ordnance velocity impact. Based on the numerical results, it has been found that the ogive nose projectile having tungsten alloy material is more effective undergoing ordnance velocity impact compared to steel 4340 material. For a given target plate thickness, spinning velocity, and impact velocity, the residual velocity is about 3 percent higher for the projectile made up of tungsten alloy compared to the steel 4340. The effects of the target plate thickness on the residual velocity of the ogive nose projectile do not seem to have much significant effects. It may be due to the simple reason that the ratio of the target plate thickness to projectile diameter is remaining within the intermediate range, i.e. within 1 and 10.

Target Configurations for Plate-Impact Recovery Experiments

1992 ◽  
Vol 59 (2) ◽  
pp. 305-311 ◽  
Author(s):  
S. N. Chang ◽  
D.-T. Chung ◽  
Y.-F. Li ◽  
S. Nemat-Nasser
Keyword(s):  
Free Edge ◽  
Surface Velocity ◽  
Thin Plates ◽  
Longitudinal Momentum ◽  
Normal Velocity ◽  
Flyer Plate ◽  
Plate Impact ◽  
Tensile Stresses ◽  
The Impact ◽  
Momentum Trap

Normal plate impact recovery experiments have been perfomed on thin plates of ceramics, with and without a back momentum trap, in a one-stage gas gun. The free-surface velocity of the momentum trap was measured, using a normal velocity (or displacement) interferometer. In all recovered samples, cross-shaped cracks were seen to have been formed during the impact, at impact velocities as low as 27 m/s, even though star-shaped flyer plates were used. These cracks appear to be due to in-plane tensile stresses which develop in the sample as a result of the size mismatch between the flyer plate and the specimen (the impacting area of the flyer being smaller than the impacted area of the target) and because of the free-edge effects. Finite element computations, using PRONTO-2D and DYNA-3D, based on linear elasticity, confirm this observation. Based on numerical computations, a simple configuration for plate impact experiments is proposed, which minimizes the inplane tensile stresses allowing recovery experiments at much higher velocities than possible by the star-shaped flyer plate configuration. This is confirmed by normal plate impact recovery experiments which produced no tensile cracks at velocities in a range where the star-shaped flyer invariably introduces cross-shaped cracks in the sample. The new configuration includes lateral as well as longitudinal momentum traps.

Unusual Microstructure in Shock-Compacted Graphite

1970 ◽  
Vol 28 ◽  
pp. 474-475
Author(s):  
Lucien F. Trueb
Keyword(s):  
Mechanical Characteristic ◽  
Compression Wave ◽  
Gray Zone ◽  
Flyer Plate ◽  
Compacted Graphite ◽  
The Impact

Crushed and statically compressed Madagascar graphite that was explosively shocked at 425 kb by means of a planar flyer-plate is characterized by a black zone extending for 2 to 3 nun below the impact plane of the driver. Beyond this point, the material assumes the normal gray color of graphite. The thickness of the black zone is identical with the distance taken by the relaxation wave to overtake the compression wave.The main mechanical characteristic of the black material is its great hardness; steel scalpels and razor blades are readily blunted during attempts to cut it. An average microhardness value of 95-3 DPHN was obtained with a 10 kg load. This figure is a minimum because the indentations were usually cracked; 14.8 DPHN was measured in the gray zone.

Use of thermomechanical pulp fibers from waste woods for making eco-friendly cushioning material

TAPPI Journal ◽  
2010 ◽  
Vol 9 (7) ◽  
pp. 15-21 ◽  
Author(s):  
JI-YOUNG LEE ◽  
CHUL-HWAN KIM ◽  
JEONG-MIN SEO ◽  
HO-KYUNG CHUNG ◽  
KYUNG-KIL BACK ◽  
...  
Keyword(s):  
Impact Test ◽  
Product Distribution ◽  
Expanded Polystyrene ◽  
Thermomechanical Pulp ◽  
Fiber Structure ◽  
Pulp Fibers ◽  
Cationic Starch ◽  
Thermal Insulating ◽  
Surface Sizing ◽  
The Impact

Eco-friendly cushioning materials were made with thermomechanical pulps (TMPs) from waste woods collected from local mountains in Korea, using a suction-forming method without physical pressing. The TMP cushions had superior shock-absorbing performance, with lower elastic moduli than expanded polystyrene (EPS) or molded pulp. Even though the TMP cushions made using various suction times had many voids in their inner fiber structure, their apparent densities were a little higher than that of EPS and much lower than that of molded pulp. The addition of cationic starch contributed to an increase in the elastic modulus of the TMP cushions without increasing the apparent density, an effect which was different from that of surface sizing with starch. In the impact test, the TMP cushions showed a more ductile pattern than the brittle EPS. The porosity of the TMP cushion was a little less than that of EPS and much greater than that of molded pulp. The porous structure of the TMP cushions contributed to their excellent thermal insulating capacity, which was equivalent to that of EPS. In summary, the TMP packing cushions showed great potential for surviving external impacts during product distribution.

scholarly journals 2-Piece Cork Stoppers as Alternative for Valorization of Thin Cork Planks: Analysis by LCA Methodology

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 873
Author(s):  
Francisco Javier Flor-Montalvo ◽  
Agustín Sánchez-Toledo Ledesma ◽  
Eduardo Martínez Cámara ◽  
Emilio Jiménez-Macías ◽  
Jorge Luis García-Alcaraz ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Raw Materials ◽  
Lca Methodology ◽  
Significant Difference ◽  
Different Dimensions ◽  
The Impact ◽  
Different Thickness ◽  
Cork Stoppers ◽  
Wine Bottle

Natural stoppers are a magnificent closure for the production of aging wines and unique wines, whose application is limited by the availability of raw materials and more specifically of cork sheets of different thickness and quality. The growing demand for quality wine bottle closures leads to the search for alternative stopper production. The two-piece stopper is an alternative since it uses non-usable plates in a conventional way for the production of quality caps. The present study has analyzed the impact of the manufacture of these two-piece stoppers using different methodologies and for different dimensions by developing an LCA (Life Cycle Assessment), concluding that the process phases of the plate, its boiling, and its stabilization, are the phases with the greatest impact. Likewise, it is detected that the impacts in all phases are relatively similar (for one kg of net cork produced), although the volumetric difference between these stoppers represents a significant difference in impacts for each unit produced.

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