Showing papers in "Defence Technology in 2016"

TL;DR: In this paper, the effect of kenaf fiber orientation on the mechanical properties of Kenaf-aramid hybrid composites for military vehicle's spall liner application is presented.

TL;DR: In this paper, an attempt has been made to evaluate the mechanical properties and microstructural characteristics of AA2519-T87 aluminium alloy joints made by FSW and UWFSW processes.

TL;DR: In this article, a laser welding process has been optimised for P92 material by using Taguchi based grey relational analysis (GRA), which has been carried out using a 3.5 kW diffusion cooled slab CO2 laser by varying laser power, welding speed and focal position.

TL;DR: A short review of the literature of azo-bridged triazoles (mainly 1,2,4-triazoles), some of their derivatives (chloromethyl, dinitro and trinitro pyrazole substituted ones, etc.) and their salts, have been presented focusing on the most recent investigations as mentioned in this paper.

TL;DR: In this paper, an analytical method of predicting the ballistic behavior of surface composites was developed based on energy balance, i.e., the initial energy of impact is same as that of energy absorbed by multi layers.

TL;DR: In this article, the comparative strategies involved in the syntheses of HNIW with respect to economical and environmental aspects are presented, and a compilation of available literature on the aforementioned characteristic properties for obtaining a value added e-HNIW is discussed here.

TL;DR: A review of thermobaric (TBX) and enhanced blast explosives (EBX) that are concentrated on studies that include their compositions, properties, reactive metal components, modeling and computations are presented in this article.

TL;DR: In this article, a multi-field coupled model of a railgun was presented, which was composed of electromagnetic field, thermal field and structural field, and the magnetic diffusion equations were solved by a finite-element boundary-element coupling method.

TL;DR: Bead-on-plate friction stir welds were made on P91 alloy with low and high rotational speeds (100 and 1000 RPM) to study their effects on weld microstructural changes and impression creep behavior as discussed by the authors.

TL;DR: In this article, an economic dependence between subsystems (paired and unpaired) is proposed, and then the maintenance cost and time under different economic dependences are formulated in a simple and consistent manner.

TL;DR: In this article, the corrosion behavior of bronze alloy prepared by equal channel angular pressing (ECAP) was investigated in 3.5 wt. NaCl solution and the results showed that ECAPed bronze samples exhibited higher corrosion resistance compared with the as-cast alloy and passive current density decreased with increasing number of passes.

TL;DR: In this paper, the thermal properties of DMR-249A steel weld joints manufactured by SMAW and activated gas tungsten arc welding (A-GTAW) processes were studied using Finite Element Model (FEM) simulation.

TL;DR: In this paper, a power series representation of the normalized depth of penetration of a tungsten long rod impact was derived for four types of ceramics: AD-995 alumina, aluminum nitride, silicon carbide, and boron carbide.

TL;DR: A scalable synthesis method for producing boron nitride nano-particles that can be readily dispersed into propellants has been developed in this article, and even dispersion of the nanoparticles in a double-base propellant has been demonstrated using a solvent-based processing approach.

TL;DR: In this article, the phase morphologies and crystal composition of synthesized nano-catalysts were examined using Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS) and Fourier Transform Infrared Spectrography (FTIR) methods.

TL;DR: In this article, the influence of confinement and prestress on cone cracking and transition velocity is investigated, and it is shown that prestress will suppress the formation and growth of the cone crack by lowering the driving stress.

TL;DR: The tuneable effects concept as discussed by the authors is aimed at achieving selectable blast and fragmentation output, to enable one charge to be used in different scenarios requiring different levels of fragmentation lethality.

TL;DR: In this article, a rotating non-consumable rod (CP Mo or AISI 304) was applied to the upper sheet of a metallic stack clamped under pressure, and an axial force was applied as the distal end of the rod touched the top portion of the upper metallic sheet.

TL;DR: In this article, the authors examined the ricochet and penetration behavior in sand, water and gelatin by steel spheres, 7.62mm APM2 and 25 mm projectiles.

TL;DR: In this article, the susceptibility to hydrogen assisted cracking of DMR-249A steel welds made using this electrode has been assessed using implant test, and it was observed that both the steel and the welding consumable are not susceptible to hydrogen-assisted cracking even with a high diffusible hydrogen level of 9 mL/100g of weld metal.

TL;DR: In this article, the influence of different welding processes on the mechanical properties and corresponding variation in the microstructural features have been investigated for the dissimilar weldments of 18% Ni maraging steel 250 and AISI 4130 steel.

TL;DR: In this paper, a flash X-ray imaging method has been developed, which provides up to eight flash radiographs in one experiment, which is used to visualize and analyze the penetration of 7.62 mm AP projectiles into three different types of SiC ceramics.

TL;DR: In this article, the failure of a shear screw which connects the separation band and band end block has been attributed to combined effect of stress and corrosion leading to stress corrosion cracking.

TL;DR: In this paper, the authors illustrated the difference between skin effect and proximity effect, and the influencing factors of proximity effect were investigated, and showed that the current is concentrated on the surface around rails due to the skin effect, while the proximity effect exacerbates the current density on the inner surfaces of rails.

TL;DR: In this article, a theoretical solution of the total yaw angle function with the cyclical yawing forces is deduced utilizing the 7 degrees of freedom (7-DOF) model designed for this calculation.

TL;DR: In this article, the authors investigated how the stiffness of the adhesive affects the failure of ceramic tiles adhered to metallic backings, and found that a higher fracture strain caused a larger deformation of the backing compared to adhesives, which exhibit a high tensile strength and low fracture strains.

TL;DR: An analytical model for calculating the propagation time of shock wave in a wave shaper is presented in this article, which shows that the contours of three typical detonation waves, such as conical detonation wave, spherical detonation and planar detonation, can be formed in the main charge by changing the thickness of wave shapers.

TL;DR: In this article, a 30mm electrothermal-chemical (ETC) gun experimental system is employed to investigate the burning rate characteristics of 4/7 high-nitrogen solid propellant.

TL;DR: The effect of small variations of target hardness on the depth of penetration for nominally identical target material has not been addressed systematically in publications yet and is often neglected as mentioned in this paper, however, it is worth noting that the authors in this paper present a linear regression analysis of penetration vs. hardness, which shows that small yaw angles and slight variations of impact velocities provide a smaller variation of the semi-infinite penetration depths than a variation of target hardening.

TL;DR: In this paper, a 3D numerical model was introduced to simulate and analyze the generation mechanism and evolution of the rail gouging phenomenon, which showed that a rail surface bulge is an important factor to induce gouging.