WO2018161072A1

WO2018161072A1 - Projectile-stopping plates for personal, vehicular and equipment protection

Info

Publication number: WO2018161072A1
Application number: PCT/US2018/020889
Authority: WO
Inventors: Mohamed A. BAKR; Khalil Ibrahim EI KHODARY
Original assignee: The American University In Cairo
Priority date: 2017-03-03
Filing date: 2018-03-05
Publication date: 2018-09-07

Abstract

A projectile-stopping panel is composed of a thermomechanically treated base plate (100) drilled with a uniform array of uniformly spaced holes of pre-determined depth and profile, and an array of thermomechanically treated pins (102) mounted onto the array of uniformly space holes of the base plate. In one embodiment, the thermomechanically treated base plate is a piece of flat steel and each pin is made of an alloy steel and has an axisymmetric profile.

Description

TITLE OF THE INVENTION

Projectile-Stopping Plates for Personal, Vehicular and Equipment Protection

FIELD OF THE INVENTION

The invention relates to defensive shielding. More specifically, it relates to armor plates for shielding against ballistics.

BACKGROUND OF THE INVENTION

Various types of ballistic armor plates are known, such as disclosed in US20100212484, US9207048, US20140007762, EP0151011. Existing armor plate designs, however, suffer from one or more disadvantages, such as use of specialized materials and high cost of manufacture.

BRIEF SUMMARY OF THE INVENTION

An armor plate design is provided that resists penetration from projectiles, including high-energy projectiles, by enacting an impact-adaptive combination of rigid body, deflective, and dynamic deformational mechanisms. The design relies mainly on a properly designed array of specifically modeled pins that are suitably mounted on an appropriate base plate. The design permits (a) near instantaneous blunting of the projectile impact front from quasi -punctal to areal, (b) near concurrent multi-component engagement of an individual projectile by the assembly, (c) multi- modal surficial and through-thickness mechanisms in pins and plate, that interact with each individual projectile and its incident/associated energies, designed to coact and prevent projectile penetration of the base plate.

Embodiments of the invention have applications to personal, vehicular and equipment protection against (high-energy) projectiles. It is affordable, rapidly produced and amenable to large scale production and wide-scale deployment.

Key advantages include: Embodiments use widely available materials, and manufacturing technology. It provides relatively thin base plates the ability to stop high energy projectiles. The pin assembly is often comparatively low weight to the base plate, but dominates the non- penetrability of the assembly. In one aspect, the invention provides a projectile-stopping panel comprising a thermomechanically treated base plate drilled with a uniform array of uniformly spaced holes of pre-determined depth and profile, and an array of thermomechanically treated pins mounted onto the array of uniformly space holes of the base plate. In one embodiment, the thermomechanically treated base plate is a 5-10 mm thick piece of flat steel and wherein each hole of the uniform array of uniformly spaced holes has a 5 mm diameter and 5 mm depth, and each pin of the array of thermomechanically treated pins is made of an alloy steel and has an axisymmetric profile and has a cylindrical neck 3 mm long and 5 mm in diameter.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Fig. 1 is a cross-sectional view of a Projectile Stopping Panel, according to an embodiment of the invention.

Fig. 2 is a fontal view of a Projectile Stopping Panel after a projectile field test, according to an embodiment of the invention.

Fig. 3 is a rear view of the Projectile Stopping Panel of Fig. 2 after a projectile field test, according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

This design permits for the first time relatively thin plates of ordinary material grade to resist high- energy projectile penetration.

Key features include:

• A relatively thin base plate is drilled with multiple blind/through holes of pre-determined depth and profile, possibly threaded, to hold an array of purpose-designed pins.

• The base plate is thermomechanically treated for appropriate strength/toughness requirements, with a knowledge of projectile and pin properties.

• Profiled pins are designed and mounted onto the base plate, with variable frontal overlap of the pin-heads, to meet and interact with incident projectiles.

• The Pins are themselves thermomechanically treated for appropriate strength/toughness requirements, with a knowledge of projectile and plate properties. • Due to the lightweight of the assembly, and flexibility/modularity of the design, it serves well for personal, vehicular and/or equipment protection.

• Due to the simplicity of the involved components and the typical grade/treatment of alloys/materials used, the resulting assembly is very low cost.

· The design of the plate is scalable and extends to large scale vehicular protection.

Fig. 1 is a cross-sectional view of one possible embodiment of the Projectile Stopping Panel (PSP) having a base plate 100 and array of mounted pins 102. The projectile 104 can impact the panel at any grazing angle 0< Θ <180°. In this embodiment 5-10 mm thick flat steel base plates were selected, of different grades (e.g. AISI 4340, S7, K600). The plates are thermally treated to the optimal toughness/hardness combination (by heating to 850 °C, water quenching, then tempering at 400 °C. Performed on multiple stages). A uniformly spaced periodic array of blind holes (5 mm diameter) was drilled into the base plate, such as to accommodate the shown pins with a transition or interference fit of 30 μπι (diametrically). Pin in this embodiment are AISI 4340 or K600, heat treated to a hardness of 65 HRC (to exceed that of the selected projectile 7.62x39 mm, HRC 60). The pins in this embodiment were axisymmetric of conical, mildly concave, and mildly convex profiles (max diameter 12 mm), and a very small rounded tip to face the projectile, and end with a cylindrical neck (3 mm long) to fit in the holes, with both the transition and interference fits. The holes are 5 mm deep in this embodiment. The pins rise between 0.5-1 mm above the plate. They are produced by standard turning operations. Each pin is itself of a size comparable to the projectile in this embodiment. In general, the pin size is always relatable to projectile and plate sizes (to instigate appropriate projectile stopping mechanisms), though not necessarily comparable. Multiple field tests were performed on this first embodiment of a PSP, for more than ten 5 mm- 10 mm plates. As shown for a 8 mm plate example Fig. 2 and Fig. 3, each has stopped the 7.62x39 mm projectile (fired from a 10-22.5 m distance), without any plate penetration, and only minimal plate deformation. The same steel grades were tested, without our pin assembly, and a 12.5mm plate was barely enough to stop the same 7.62x39 mm projectile, with clear evidence of penetration & excessive plate deformation. Fig. 2 is a fontal view of PSP after 7.62x39 mm projectile field test. The PSP plate 200 has an array of pins such as pin 202. The region of impact 206 is indicated. The directly impacted pin at the center of the circle is broken in place, while many other pins are seen to have flown out-of- place due to impact, leaving empty holes such as hole 204.

Fig. 3 is a rear view of the base plate 200 of Fig. 2 after 7.62x39 mm field test, indicating a cracking of the base plate within the region of impact 206.

Claims

1. A projectile-stopping panel comprising:

a thermomechanically treated base plate drilled with a uniform array of uniformly spaced holes of pre-determined depth and profile;

and

an array of thermomechanically treated pins mounted onto the array of uniformly space holes of the base plate.

2. The projectile-stopping panel of claim 1 wherein the thermomechanically treated base plate is a 5-10 mm thick piece of flat steel and wherein each hole of the uniform array of uniformly spaced holes has a 5 mm diameter and 5 mm depth.

3. The projectile-stopping panel of claim 1 wherein each pin of the array of

thermomechanically treated pins is made of an alloy steel and has an axisymmetric profile and has a cylindrical neck 3 mm long and 5 mm in diameter.