The effect of impact velocity and target thickness on ballistic performance of layered plates using Taguchi method

2014 ◽  
Vol 53 ◽  
pp. 719-726 ◽  
Author(s):  
Ravindranadh Bobbili ◽  
Ashish Paman ◽  
V. Madhu ◽  
A.K. Gogia
Keyword(s):  
Taguchi Method ◽  
Impact Velocity ◽  
Target Thickness ◽  
Layered Plates ◽  
Ballistic Performance

Target Size Effects on Foreign Object Damage in Gas-Turbine Grade Silicon Nitrides by Ceramic Ball Projectiles

2010 ◽  
Author(s):  
Sung R. Choi ◽  
Zsolt Ra´cz
Keyword(s):  
Silicon Nitride ◽  
Gas Turbine ◽  
Impact Velocity ◽  
Impact Damage ◽  
Target Thickness ◽  
Foreign Object ◽  
Silicon Nitrides ◽  
Foreign Object Damage ◽  
Post Impact ◽  
Grade Silicon

Foreign object damage (FOD) phenomena of two gas-turbine grade silicon nitrides (AS800 and SN282) were determined at ambient temperature using impact velocities ranging from 25 to 150 m/s by 1.59-mm diameter silicon nitride ball projectiles. Targets in flexure bar configuration with two different thicknesses of 1 and 2 mm were impacted under a fully supported condition. The degree of impact damage as well as of post-impact strength degradation increased with increasing impact velocity, increased with decreasing target thickness, and was greater in SN282 than in AS800 silicon nitride regardless of target thickness. The critical impact velocity, in which targets fractured catastrophically, decreased monotonically with decreasing target thickness and was lower in SN282 than in AS800. Backside cracking was dominant in both AS800 and SN282 target specimens with a thickness of 1 mm, occurring from an impact velocity of 50 m/s. A backside cracking analysis based on the elastic foundation approach was made as a function of target thickness. Overall, FOD by ceramic projectiles was significantly greater than that by hardened metallic counterparts.

An Examination of DOP Test of Ceramic Tile Subjected to Long Rod Penetration

2014 ◽  
Vol 566 ◽  
pp. 353-358
Author(s):  
Jian Ming Yuan ◽  
Geoffrey E.B. Tan
Keyword(s):  
Numerical Solution ◽  
Impact Velocity ◽  
Ceramic Tile ◽  
Tungsten Alloy ◽  
Ceramic Tiles ◽  
Depth Of Penetration ◽  
Ballistic Performance ◽  
Long Rod ◽  
Multilayered Materials ◽  
The Impact

Depth of penetration (DOP) test of ceramic tile subjected to long rod impact was analyzed by applying the Tate model. This paper investigated the influence of impact velocity and tile thickness on the ballistic performance measurement of the tested ceramic tiles. DOP test was simplified as an eroding rod penetrating a target composed of multilayered materials. Through applying the Tate model, the method of obtaining the numerical solution was proposed. For a constant impact velocity, it was found that the measured differential tile efficiency (DEF) was independent of the thickness of the ceramics tiles. But the measured DEF decreased as the impact velocity increased. These analytical conclusions were verified by the using of the results of DOP tests of SiC and Al2O3 tiles subjected to impact of long tungsten alloy rods at a nominal impact velocity of 1.3 km/s.

Dynamic Fracture of Layered Plates Subjected to In-Plane Bending

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Servesh Kumar Agnihotri ◽  
Venkitanarayanan Parameswaran
Keyword(s):  
Dynamic Loading ◽  
Impact Velocity ◽  
High Speed ◽  
Thermal Protection ◽  
Strain History ◽  
High Speed Imaging ◽  
Layered Plates ◽  
Pmma Layer ◽  
Crack Tips ◽  
The One

Layered structures typically used in applications such as windshields, thermal protection systems, heavy armor, etc., have property jumps at the layer interfaces. Present study focuses on understanding crack initiation and propagation in such systems under dynamic loading particularly when the property jumps are across the crack front. Layered plates were fabricated by joining polymethylmethacrylate (PMMA) and epoxy sheets using an epoxy-based adhesive (Araldite). Single-edge notched (SEN) specimens were subjected to dynamic loading using a modified Hopkinson bar setup. High-speed imaging coupled with dynamic photoelasticity was used to record the crack-tip isochromatic fringes from which the stress intensity factor (SIF) history was obtained. In selected experiments, a pair of strain gages installed on surfaces of specimen was used to record the strain history in the layers, from which the SIF in each layer was obtained. The results indicated that, prior to crack extension, the strain in both layers was identical. The crack tips in the layers start extending at different time instants with the one in the relatively brittle epoxy layer extending first followed by the one in the PMMA layer. At low impact velocity, the delay obtained was significantly higher than that at high impact velocity. The speed of epoxy crack was lower initially due to the bridging of the crack by the uncracked portion of the PMMA layer till initiation of the crack in the PMMA layer. This effect reduced at higher impact velocity for which the delay was much lower and the cracks propagated at a higher-speed.

Numerical Simulation on Effect of Impact Velocity and Target Thickness in Magnesium Alloy AZ31B

2015 ◽  
Vol 787 ◽  
pp. 291-295
Author(s):  
B. Ezhil Vendhan ◽  
K.L. Hari Krishna ◽  
A.K. Lakshminarayanan
Keyword(s):  
Magnesium Alloy ◽  
Impact Velocity ◽  
Shear Force ◽  
Failure Mechanisms ◽  
Plate Thickness ◽  
Target Thickness ◽  
Light Weight ◽  
Varying Thickness ◽  
Magnesium Alloy Az31b ◽  
Simulation Results

Recent research works indicate that magnesium alloy can be used for constructing light weight armor because of its density, which is 35% lower than aluminium and 77% lower than steel and also it exhibits superior vibration damping and better failure mechanisms than the contemporary ballistic materials. In this study, numerical simulations were carried out in a monolithic magnesium AZ31B plate using AUTODYN software to understand the effect of Impact velocity and plate thickness on the deformation of target plates. The projectiles are normally impacted on target plates of varying thickness plates at different velocities. Lagrangian solver was used for meshing, in which the grid developed by the solver distorts with the material helps in eliminating the inaccuracies caused by the cell growth due to the shear force of the bullet impact. The simulation results are verified with the experimental data available in the literature.

Ballistic performance and damage simulation of fiber metal laminates under high-velocity oblique impact

2020 ◽  
Vol 29 (7) ◽  
pp. 1011-1034 ◽  
Author(s):  
Chao Zhang ◽  
Qian Zhu ◽  
Jose L Curiel-Sosa ◽  
Tinh Quoc Bui
Keyword(s):  
Impact Velocity ◽  
High Velocity ◽  
Damage Mechanics ◽  
Failure Modes ◽  
Element Model ◽  
Oblique Impact ◽  
Ballistic Performance ◽  
Fiber Metal Laminates ◽  
Fiber Metal ◽  
The Impact

Fiber metal laminates have been successfully applied in military aircrafts, armor vehicles and other modern engineering industries as protective structures due to their outstanding impact resistant properties. Prediction of the ballistic performance and investigation on the damage mechanism of the fiber metal laminates under general oblique impact conditions still remain a very challenging issue. In this study, a nonlinear dynamic finite element model in terms of continuum damage mechanics including intra- and inter-layer failure modes is presented. The accuracy of this model is validated with available experimental data. The damage and ballistic performance of two different structural fiber metal laminates subjected to high-velocity oblique impact by rigid hemispherical nose projectile with angles of 0°, 30°, 45° and 60° are studied. The numerical results show that the projectile deflects when the oblique impact occurs and the deflection angle decreases with increasing the impact velocity. The residual velocity of the projectile and the energy absorption of the target are related to the initial impact velocity and impact angle of the projectile. The proposed simulation approach offers a new proper reference for numerical investigations of common oblique impact problems in other fiber metal laminates.

Damages Caused by Projectile Impact

2016 ◽  
Vol 689 ◽  
pp. 29-33
Author(s):  
Adnan I.O. Zaid
Keyword(s):  
Plastic Deformation ◽  
Phase Transformation ◽  
Impact Velocity ◽  
Incident Angle ◽  
Shear Bands ◽  
Local Stress ◽  
Target Thickness ◽  
Target Plate ◽  
Reflected Waves ◽  
Plug Formation

Impact conditions involve velocities below the sonic speed, which is normally of the order few hundreds up to few thousands m/s. The implications of impact depend on projectile and target materials, impact velocity, incident angle and the mass and shape of the projectile impacting head. The superimposition of progressing and reflected waves can lead to local stress levels that exceed the material’s strength, thus causing cracks and / or fracture at significant velocities. At low impact velocities, plastic deformation normally prevails. With increasing velocities the projectile will leave a hole in the target. With decreasing target thickness, the effects range from perforation, via internal cracks, and finally to plug formation. In this paper, the damages caused by impact which include: perforation, plugs formation and their fracture, metallurgical changes e.g. shear bands, twinning, recrystallization and phase transformation and fractures both in the projectile and the target plate are presented and discussed.

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