Multilayer graphene is an exceptional anisotropic material due to its layered structure composed of two-dimensional carbon lattices. Although the intrinsic mechanical properties of graphene have been investigated at quasi-static conditions, its behavior under extreme dynamic conditions has not yet been studied. We report the high–strain-rate behavior of multilayer graphene over a range of thicknesses from 10 to 100 nanometers by using miniaturized ballistic tests. Tensile stretching of the membrane into a cone shape is followed by initiation of radial cracks that approximately follow crystallographic directions and extend outward well beyond the impact area. The specific penetration energy for multilayer graphene is ~10 times more than literature values for macroscopic steel sheets at 600 meters per second.

Dynamic mechanical behavior of multilayer graphene via supersonic projectile penetration

Parameters influencing the impact response of fiber-reinforced polymer matrix composite materials: a critical review

In the present study, effect of hybridization on the hybrid composite armors under ballistic impact is investigated using hydrocode simulations. The hybrid composite armor is constructed using various combinations and stacking sequences of fiber reinforced composites having woven form of fibers specifically high speciﬁc-modulus/high speciﬁc-strength Kevlar fiber (KF), tough, high strain-to-failure fiber Glass fiber (GF) and high strength/high stiffness Carbon fiber (CF). Different combinations of composite armors studied are KF layer in GF laminate, GF layer in KF laminate, KF layer in CF laminate and CF layer in KF laminate at various positions of hybridized layers for a fixed thickness of the target. In this article the results obtained from the finite element model are validated for the case of KF layer in a GF laminate with experimental predictions reported in the literature in terms of energy absorption and residual velocity and good agreement is observed. Further, the effect of stacking sequence, projectile geometry and target thickness on the ballistic limit velocity, energy absorbed by the target and the residual velocity are presented for different combinations of hybrid composite armors. The simulations show that, at a fixed thickness of the hybrid composite armor, stacking sequence of hybridized layer shows significant effect on the ballistic performance. The results also indicate energy absorption and ballistic limit velocity are sensitive to projectile geometry. Specifically, it is found that arranging the KF layer at the rear side, GF layer in the exterior and CF layer on the front side offers good ballistic impact resistance. The hybrid composite armor consisting of a CF layer in KF laminate acquires maximum impact resistance and is the best choice for the design compared to that of other combinations studied.

The effect of hybridization on the ballistic impact behavior of hybrid composite armors

Plastics in engineering

The energy absorption behavior of hybrid composite laminates containing nano-fillers under ballistic impact

Ballistic impact performance of Kevlar-29 and Al2O3 powder/epoxy targets under high velocity impact

The importance of penetration and perforation into targets in both, military and civilian application has made it the subject of many investigations. The current investigation is focused on the ballistic performance of Polymethylmethacrylate (PMMA) under impact by a rigid spherical projectile in the range of 89.3 – 670 m/s. An analytical model for the ballistic limit velocity from the work done for target based on the experimental observations is suggested. The results are discussed in terms of the work done in causing the failure modes coupling this work with the projectiles kinetic energy drop and its effect on the ballistic limit velocity. The effect of target thickness on the velocity is then discussed. The experimental results showed good agreement compared with Ipson and Recht equation.

Behaviour of transparent material under high velocity impact

This project aims at determining both numerical and experimental to some thermal properties and its thermal expansion coefficient, thermal conductivity and mechanical properties of reinforcement of fiber glass woven with matrix of multi wall carbon nanotube MWCNT / epoxy composite. First, this powder is known to have a very good thermal properties. So, the nanopartical combined with resin has poor thermal properties. Secondly, the development a complete solution for the manufacturing of multi wall carbon nanotube /epoxy composites different volume fraction from 1% to 10% with increment of 2% to compare the result of finite element method by using ANSYS program with experimental results to determine the mechanical and thermal properties for nanocomposite materials. The finite element by using ANSYS is good agreement with experimental data for different volume fraction. The thermal conductivity of the nanocomposite materials increases with increasing in the volume fraction concentration thermal expansion coefficient reduces with increasing in the volume fraction concentrations. The increment nano particle concentration effect on the mechanical properties is accomplished the best results.

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Study of thermal and mechanical properties of fiber-glass multi-wall carbon nanotube/epoxy

Many uses of aluminum led the researchers to develop this field by changing the target bullion to obtain alloys suitable for all specialties and possibilities. Adding some metals to aluminum leads to a change in properties, whether mechanical or physical, but in our research we target the mechanical properties, adding magnesium and zinc are in equal proportions (5%Mg-5%Zn, 10%Mg-10Zn). We offer this alloy to some tests such as hardness test, electrical conductivity test, compression test and Microstructure examination test. We compare the properties obtained with each other and with the basic properties of pure basic metal according to international standards.

Effect of Addition of Magnesium and Zinc to Obtain Optimal Mechanical Properties of Al-Mg-Zn Alloy

In this study, the behaviour of laminated composite plates, fiber Kevlar29, Al2O3powder/epoxy and the suggested analytical solution for static analysis of composite plates were presented using general classical laminated plate theory. The Navier solutions are limited to simply support rectangular plates using static analysis. The results show that the effect of the deflections and stresses on the plate thickness–to–length ratio, aspect ratio, modulus ratio, fiber orientation and the number of layers were observed. The deflection and stresses on laminated composite plate decreases with the increase in the number of layers, fiber orientation, and thickness of the laminated plates. These results indicate that the improvements in mechanical properties for aircraft body applications were achieved.

	 

	Key words: Composite materials, laminated plates, mechanical properties, Navier solution, deflection plate.

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Luay Hashem Abbud

Papers

Ballistic impact performance of Kevlar-29 and Al2O3 powder/epoxy targets under high velocity impact

Behaviour of transparent material under high velocity impact

Study of thermal and mechanical properties of fiber-glass multi-wall carbon nanotube/epoxy

Effect of Addition of Magnesium and Zinc to Obtain Optimal Mechanical Properties of Al-Mg-Zn Alloy

Mechanical properties of interlaminer Kevlar29 and Al2O3 powder/epoxy composite plates using an analytical approach