Aluminum Armor Panel with Composite Layer for Ballistic Protection

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Solution Overview

Problem

Existing armor panels face challenges in achieving a balance between armor-piercing (AP) and fragment-simulated projectile (FSP) protection while being cost-effective and lightweight, as materials with good AP resistance often perform poorly in FSP tests and vice versa, and current solutions require complex and expensive production processes.

Innovation Solution

An aluminum alloy armor panel with a specific chemical composition (7.5% ≤ Zn ≤ 9.7%, 1.5% ≤ Mg ≤ 2.9%, 1.2% ≤ Cu ≤ 2.1%, and other elements within specified limits) combined with a composite reinforcing layer of high mechanical performance fibers like aramid or Kevlar, which provides enhanced ballistic protection with a surface density less than 100 kg/m².

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metal armor panels (steel, aluminum, titanium) are used to stop armor-piercing projectiles, then kinetic energy absorption is excellent, but weight increases significantly reducing efficiency

Engineering Contradiction:
Improvekinetic energy absorptionVSAvoidpanel weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent applies composite materials by combining an aluminum alloy plate with a ceramic layer on the projectile-facing side and a composite reinforcing layer on the rear side. This composite structure achieves excellent kinetic energy absorption while maintaining lower weight compared to solid steel or titanium panels, as each layer contributes specific properties: the aluminum alloy provides baseline strength, the ceramic absorbs and dissipates projectile kinetic energy, and the reinforcing layer prevents fragmentation without requiring heavy metal construction throughout.

Inventive Principle:
Principle #40Composite materials

2Strength

If ceramic products are placed on the projectile-facing side of composite panels, then projectile stopping capacity increases, but production cost increases significantly

Engineering Contradiction:
Improveprojectile stopping capacityVSAvoidproduction cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent uses composite materials to achieve projectile stopping capacity while controlling production cost. The aluminum alloy plate serves as a cost-effective substrate that is easier and cheaper to manufacture than solid ceramic or titanium armor. The ceramic layer is applied only where most needed (on the projectile-facing side), and the composite reinforcing layer on the rear provides necessary protection at lower cost than solid metal construction, creating an optimized balance between performance and manufacturability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The armor panel is segmented into three distinct functional layers: an aluminum alloy plate providing structural baseline, a ceramic layer on the projectile-facing side for kinetic energy absorption, and a composite reinforcing layer on the rear side for fragmentation prevention. This segmentation allows each component to be optimized independently and manufactured separately, reducing overall production complexity and cost compared to monolithic armor designs.

Inventive Principle:
Principle #1Segmentation

3Weight of moving object

If aluminum alloy plates are used for armor panels, then weight is reduced, but FSP resistance performance becomes average

Engineering Contradiction:
Improvepanel weightVSAvoidFSP resistance
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent applies composite materials by coating the aluminum alloy plate with a composite reinforcing layer comprising high-performance fibers (such as aramid, glass, or polyethylene) on the rear side. This composite layer significantly enhances FSP resistance by absorbing impact energy from fragmented debris while maintaining the lightweight advantage of the aluminum substrate, achieving both weight reduction and improved reliability against fragment-simulated projectiles.

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution achieves improved AP and FSP protection with a lower surface density, allowing for level 5 protection defined in STANAG 4569, with significant gains in FSP performance even with a thin composite reinforcement layer, particularly with 7xxx series aluminum alloys and Kevlar 129 fabric layers.

Implementation Method 1

the ability to stop the projectiles, to absorb their kinetic energy without emitting dangerous debris

Methodology Applied
Scientific EffectKinetic energy absorption:

Implementation Method 2

a composite reinforcing layer comprising reinforcing fibers or strips having a high mechanical performance which gives them a high ballistic protection capacity

Methodology Applied
Scientific EffectFiber reinforcement: Composite Materials

Implementation Method 3

characterizes the resistance to perforation

Methodology Applied
Scientific EffectBallistic resistance:

Implementation Method 4

excellent capacity to absorb kinetic energy from the armor-piercing projectile during an impact

Methodology Applied
Scientific EffectKinetic energy absorption:

Data Source

PatentEP2796827B1Composite panel for vehicle armour
Publication Date: 2018.04.11 CONSTELLIUM VALAIS SA AG
  • EP2796827B1 patent drawingFigure 1~2
  • EP2796827B1 patent drawingFigure 3~4
  • EP2796827B1 patent drawing

AI summary

Armor panel comprising an aluminum alloy plate and characterized in that: a) said aluminum alloy has the following chemical composition, expressed in weight percentages: 5.1% ≤ Zn ≤ 9.7% 1.5% ≤ Mg ≤ 2.9% 1.2% ≤ Cu ≤ 2.1% Si ≤ 0.4% Fe ≤ 0.5% Mn ≤ 0.3% Cr ≤ 0.28% Tri ≤ 0.2% Zr ≤ 0.15% b) said plate comprises a face intended to be exposed to impacts and a face opposite said impact-exposed face which is coated with a composite reinforcement layer comprising fibers or reinforcing strips having a high ballistic protection capacity, typically made of high mechanical performance glass, aramid or high performance polyethylene.