scholarly journals Upon Using of Plastics Layer in Light Multilayered Armor

2019 ◽  
Vol 57 (2) ◽  
pp. 265-275
Author(s):  
Catalin Adetu ◽  
Vasile Nastasescu ◽  
Alina Elena Adetu ◽  
Florian Vladulescu

The concept of ballistic protection is a subject of great importance and is defined as representing all the capabilities of the military vehicle to withstand attacks, in order to ensure protection of the crew during the missions. The projectile-plate impact research must answer a series of questions on designer or fighter behalf, among which the most important would be whether the bullet penetrates or perforates and whether the velocity after the perforation ensures a lethal effect on the personnel. The current paper presents the numerical evaluation of the working together of aluminum layers with plastic materials in a multilayer structure with honeycomb core, on impact with a rigid projectile. Plastic materials have revolutionized many industries and they are increasingly used due to their main properties, low mass and high strength. The research included the use of plastics, the positioning within the panel and the study of the two constructive versions of the structure, with coupled and uncoupled layers. Post-processing model and interpretation of the results are offered and these could be enriched and customized for other situations, similar or less similar, implicitly, the method is provided, finding a quick answer to certain questions.

1962 ◽  
Vol 6 (03) ◽  
pp. 24-32
Author(s):  
James A. Nott

A theoretical derivation is given for elastic and plastic buckling of stiffened, circular cylindrical shells under uniform external hydrostatic pressures. The theory accounts for variable shell stresses, as influenced by the circular stiffeners, and critical buckling pressures are obtained for simple support conditions at the shell-frame junctures. Collapse pressures for both elastic and plastic buckling are determined by iteration and numerical minimization. The theory is applicable to shells made either of strain-hardening or elastic-perfectly plastic materials. Using the developed analysis, it is shown that a variation in stiffener size can change the buckling pressures. Test data from high-strength steel and aluminum cylinders show agreement between the theoretical and experimental collapse pressures to within approximately six percent.


Author(s):  
Andrea Brown ◽  
Heather Millman ◽  
Bethany Easterbrook ◽  
Alexandra Heber ◽  
Rosemary Park ◽  
...  

LAY SUMMARY In 2015, the Canadian Armed Forces (CAF) implemented Operation HONOUR to eliminate sexual misconduct (SM) in the military. Sexual assault, inappropriate sexual behaviours, sexual harassment, and gender discrimination are all types of SM. Experiencing SM can result in depression, substance abuse, physical health problems, and even posttraumatic stress disorder (PTSD). Despite Operation HONOUR, SM still happens in the CAF. At this time, many groups are working together to address SM and to support those who have experienced SM. Canadian-based researchers, policymakers, military members, Veterans, and clinicians are collaborating to identify new approaches to training, culture change, research, and treatment relating to SM in the CAF. The end goal of working together is to minimize SM in the CAF and ensure the health and safety of all CAF members and Veterans.


Author(s):  
Ozan O. Varol

Balanced civil-military relations emerge from synergy. In this case synergy refers to civilians setting aside their ideological differences, working together to build credible democratic institutions, and constructing a viable alternative to military rule. If the civilians themselves are divided on the future democratic trajectory of the nation or the military’s exit from politics, the military may more easily exploit these divisions. Instead of trying for a quick power grab, civilians in an emerging democracy must shun any antidemocratic alternatives, including military interventions, to political rule. The more effective the civilian politicians are in constructing a stable, robust democracy, the less likely power vacuums and military interventions will occur. If political parties have a real chance to compete and win in the electoral marketplace, they are more likely to play the democratic game rather than violate its rules and resort to tanks and guns to oust their opponents.


2011 ◽  
Vol 368-373 ◽  
pp. 894-900 ◽  
Author(s):  
Hao Wu ◽  
Qin Fang

Based on the large amounts of field impact tests with different projectile nosed shapes, the abilities of the existing classical empirical and semi-empirical impact formulae in predicting the local damage of normal and high strength concrete targets (NSCT & HSCT) under the strike of rigid projectile were evaluated. It finds that, firstly, for the penetration depth, the Forrestal and Chen & Li semi-empirical formulae, BRL and Whiffen empirical formulae are advised for the NSCT under the impact of ogive nosed projectile; and Chen & Li semi-empirical formula and ACE empirical formulae are advised for the NSCT under the impact of special nosed projectile; the dimensionless penetration depth of NSCT increases linearly with the non-dimensional impact factor. Secondly, for the penetration depth, Chen & Li semi-empirical formula is advised for the HSCT under the mid-to-high speed impact, and the existing formulae are not applicable while the speed of the projectile was relatively low. Thirdly, for the perforation mode of the target, the BRL and Chang empirical formulae are advised for the NSCT, and the Chen semi-empirical formula, ACE and BRL empirical formulae are advised for the HSCT.


2015 ◽  
Vol 1095 ◽  
pp. 837-841 ◽  
Author(s):  
Guang Xing Huang ◽  
Bao Shou Sun ◽  
Wen Fei Peng ◽  
Xue Dao Shu ◽  
Wang Lu

Titanium alloy with high strength, corrosion resistance, heat resistance and many other advantages has widely applications in aviation industry and the military-industrial complex. The market demand for titanium alloy increases year by year. However, the rolling technology for small size titanium rod is not mature due to its poor plasticity and difficult processing. In addition, current titanium alloy bar can not meet the high-end market requirements, it still largely dependents on imports now. Developing high-quality titanium bars is a major aim of titanium industry in our country in the future. Three-roll rolling is one of mature methods in current production of titanium alloy bars. Using this processing method for rolling titanium alloy bars, multi-standard, low-volume production requirements can be achieved.


Author(s):  
Shumei Chen ◽  
Xiaomei Chen

Damper performance is important for the vehicle, especially for the military vehicle. The damper will not only improves driver’s comfort and vehicle safety factor, but also enhances the veracity and the mobility in campaign. Therefore, how to analyze the magneto-rheological damper performance and get more accurate results are extremely important. In this article, first of all, sets up the mathematical model by the desired damper, founds the formula about damping force and simulate analysis by Matlab/Simulink. Then set the relevant parameters and boundary conditions, does the computational fluid dynamics (CFD), numerical analysis of fluid dynamic properties by FLUENT. Manufactured this damper after the optimization design and validated by the test on the experimental platform. The results are shown that this damper’s performance is good for satisfying the actual requests.


2014 ◽  
Vol 584-586 ◽  
pp. 1746-1749 ◽  
Author(s):  
Yu Li Cui ◽  
Fu Guo Qian ◽  
Shu Xiu Liu ◽  
Hai Tao Yin

This paper reports the effects of hydrogen peroxide in surface morphology, strength, density, thermal conductivity of foam concrete and hydrogen peroxide utilization efficiency. The results show that these foam concretes are new and innovative building materials with interesting properties: low mass density and high strength when the addition amount of hydrogen peroxide is in 5%~6% range. Responsible for these properties are the macro-and microporosity. Macropores are created by adding hydrogen peroxide in different addition amount. It is also found that the utilization efficiency of hydrogen peroxide is higher when the addition amount of hydrogen peroxide is in the range of 5%~6%.


Author(s):  
Oleg Rikunov ◽  
Viktor Kuzhelovych Viktor

The article argues the relevance of determining the indicator of military-technical efficiency of the use of military automobile equipment by units and subunits of the National Guard of Ukraine when performing battle actions (operations). Currently, special indicators are used to assess the state of military automotive equipment, which are a numerical expression of the gauges or their relationship. Existing methods of planning technical support, methods for predicting the quantitative assessment of the military-technical efficiency indicator of the use of military automotive equipment during hostilities need further improvement. The article proposes to use a comprehensive indicator, a generalized coefficient of military-technical efficiency of using military automobile equipment during combat actions (operations), as an indicator of military-technical efficiency of using military automobile equipment in combat conditions, and to determine directions for increasing the efficiency of using military equipment. Keywords: automotive technical support; military automotive equipment; military-technical efficiency of using military automobile equipment; performance indicators; technical readiness coefficient; machine use efficiency during battle actions (operations)


2013 ◽  
Vol 415 ◽  
pp. 586-589
Author(s):  
Xiang Hong Zhang ◽  
Han Yang ◽  
Si Lian Sheng ◽  
Yan Jun Li ◽  
Li Jun Yin

In the process of military vehicle design and modification, because of the dynamotor, oil pump and other load demands, installation of power take off (PTO) is an common project which will meet different needs of users. The paper designs and summarizes the military field used in conjunction self-propelled dynamotor system of kitchen vehicle's design project, process, performance testing and test data and etc.


Author(s):  
Bela Revesz

Abstract Words can mean different things to different people. This can be problematic, mainly for those working together in a bureaucratic institution, such as the secret service. Shared, certified, explicit and codified definitions offer a counter to subjective, solitary and/or culturally dominant definitions. It’s true that codified secrecy terms for secret services can be seen to involve a number of political, cultural, subcultural “languages”, but if words come from unclassified or declassified files, memorandums and/or records, one needs a deep understanding of the secret services. A remarkable feature of this bureaucratic language is the evolving nature of, certain “keywords” as important signifiers of historical transformation. Thus, the changes in the language of the secret services depends at least as much on the internal changes of the secret services as on the transformation in the external political-social environment. In spite of the confusion of Hungarian secret services in the revolutions of 1918–1919 and the disintegration of the Austrian-Hungarian Monarchy, in the early 1920’s became a stable system. Between the two World Wars, the Hungarian State Police directed by the Ministry of Internal Affairs (hereinafter referred to as MIA), the Military Intelligence and Counter-Espionage directed by the Ministry of Defence (hereinafter referred to as MoD), and the Hungarian Royal Gendarmerie directed by both of the Ministries had their own operational service. This structure existed unchanged until 1945. Simultaneously with the forward advance of the soviet troops, government began to re-establish the former system of the secret services in the eastern part of the country. After WWII, in 1946, the “State-protection Department” as political police became independent from the police. However, from the beginning, they remained under the control of the Communist Party. After 1950, the State Security Authority provided special services for the MIA and the Military Political Directorate of the MoD. After quashing the revolution in 1956, in the spring of 1957, the MIA Political Investigation Department was established which—with slight modifications—kept the structure created during the “state protection era”. The MIA III. The State-Protection General Directorate was established in 1962. The reorganization was finalized in the middle of the 1960’s, which resulted in the new system, which—with the structure of Directorates—became the ultimate structure of the state secret police until the abolishment of the MIA General Directorate III in January 1990. These organizational transformations were largely the result of exogenous historical-political changes. Moreover, each new period had a major impact on the organizational communication, language use and vocabulary of the secret services. This study seeks to interpret these historical transformations.


Sign in / Sign up

Export Citation Format

Share Document