Factors affecting the bulletproof effectiveness of bulletproof vests

Factors affecting the bulletproof effectiveness of bulletproof vests
The factors affecting the bulletproof effectiveness of bulletproof clothing can be considered from two aspects: the interacting projectile (bullet or shrapnel) and bulletproof material. As far as the projectile is concerned, its kinetic energy, shape and material are important factors determining its penetration force. Ordinary warheads, especially lead core or ordinary steel core bullets, will deform after contacting bulletproof materials. In this process, the bullet consumes a considerable part of kinetic energy, which effectively reduces the penetration of the bullet, which is an important aspect of the bullet energy absorption mechanism. For the shrapnel produced by the explosion of bombs and grenades or the secondary fragments formed by bullets, the situation is significantly different. These shrapnel have irregular shape, sharp edges, light weight and small volume. They will not deform after hitting bulletproof materials, especially soft bulletproof materials.

Generally speaking, the velocity of such debris is not high, but it is large and dense. The key to the energy absorption of such fragments by soft bulletproof clothing is that the fragments cut, stretch and break the yarn of bulletproof fabric, and make the interaction between the yarns inside the fabric and between different layers of the fabric, resulting in the overall deformation of the fabric. In these processes, the fragments do work to the outside, so as to consume their own energy. In the above two types of body energy absorption, a small part of energy is converted into heat energy through friction (fiber / fiber, fiber / bullet) and into sound energy through impact.