အောက်ဆုံးထိ ဆွဲကြည့်ပေးကြပါ ခင်ဗျာ
A bulletproof vest, also known as a ballistic vest or a bullet-resistant vest, is an item of body amour that helps absorb the impact and reduce or stop penetration to the torso by firearm-fired projectiles and fragmentation from explosions. The vest may come in a soft form, as worn by many police officers, prison officers, security guards, and some private citizens, used to protect against stabbing attacks or light projectiles, or hard form, using metallic or para-aramid components. Soldiers and police tactical units wear hard amour, either in conjunction with soft amour or alone, to protect against rifle ammunition or fragmentation.
WHO INVENTED THE BULLETPROOF VEST?
The focus of inventing the bulletproof vest came after the assassination of Carter Harrison Sr. Zeglen. He was a Roman Catholic Priest of a parish with over 40,000 followers in Chicago. He collaborated with Jan Szczepanik to improve the initial design of the bulletproof vest in 1901. Although there has been debate about Szczepanik’s role or possibly the original inventor of the bulletproof vest, most sources agree that the modern vest was invented by Zeglen.
BULLETPROOF VEST HISTORY
The first recorded mention of bulletproof armor seems to be around 1538. It was in this year that Francesco Maria della Rovere commissioned Filippo Negroli with manufacturing a bulletproof vest. While history makes no mention of Negroli producing and testing his bulletproof vest, there are records of a version of bulletproof vests being tested as early as 1561 by the Holy Roman Emperor Maximilian II.
THE ROLE OF SILK AND BULLETPROOFING
In 1881 George E. Goodfellow made note of how silk “had significantly reduced the penetration of one of the bullets“. Following this discovery, Goodfellow started trying to understand how silk could be used to protect people from bullets. He fabricated a vest that was made from 30 layers of silk. As much as he pioneered the use of silk in bulletproof materials, he returned to being a devoted physician.
This research laid the foundation for Zeglen as he fabricated and tested a bulletproof vest made of silk. The major difference between using silk fabric and Zeglen’s design was the custom sewing methods utilized to make a higher performance ballistic fabric.
MODERN BULLETPROOF VEST ADVANCEMENTS
As with all technology, bulletproof vests have improved over time in design. Higher performance ballistic materials have been developed that protect better, are lighter weight, and last longer. The most recent advancement in bulletproof technology is the use of graphene microfibers. Citizen Armor vests with graphene microfibers are tested to NIJ level IIIA and are more flexible and lightweight than other soft body armor.
Early modern era
In 1538, Francesco Maria Della Rovere commissioned Filippo Negroli to create a bulletproof vest. In 1561, Maximilian II, Holy Roman Emperor is recorded as testing his armor against gunfire. Similarly, in 1590 Sir Henry Lee expected his Greenwich amour to be “pistol proof”. Its actual effectiveness was controversial at the time.
During the English Civil War Oliver Cromwell’s Ironside cavalry were equipped with Capeline helmets and musket-proof cuirasses which consisted of two layers of armor plate. The outer layer was designed to absorb the bullet’s energy and the thicker inner layer stopped further penetration. The armor would be left badly dented but still serviceable.
Kevlar is the most commonly used material as armour for protection against bullets used in hand guns because of its impact resistance, high strength and low weight. These properties make Kevlar an ideal material to be used in bullet-proof vests as compared to other materials. In the present study, different numbers of layers of Kevlar with different weights are tested to determine the weights and the number of layers needed to design a safe bullet-proof vest. For this purpose, several ballistic tests were performed on combinations of ballistic gel and Kevlar layers of different weights. Ballistic impacts are generated by 9 mm Parabellum ammunition. The objective is to assess the characteristics of high-speed ballistic penetration into a combination of a gel and Kevlar and determine the number of layers needed to safely stop the 9 mm bullet and thereby contribute to the design of safe bullet-proof vests. The tests provide information on the distances the bullets can travel in a gel/Kevlar medium before they are stopped and to identify the resistance capabilities of Kevlar of different grams per square meter (GSM). The tests were conducted with the use of a chronograph in a controlled test environment. Specifically, results identify the number of layers of Kevlar required to stop a 9 mm Parabellum projectile, and the effectiveness of using different number of layers of GSM Kevlar material.
Why don t army wear bulletproof vests?
The primary reason would be because it really isn’t necessary. In modern warfare, the percentage of casualties resulting from direct rifle and machine gun fire are surprisingly low. What has proven to be quite deadly is the effects of blasts from detonating artillery and aviation ordnance?
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