Understanding the Evolution of Armour Materials
Armour historically relied on metals, starting from Bronze and Iron Age helmets through to steel plates in WWI tanks following the industrial revolution. Metals dominated because they were strong, widely available, and easy to manufacture using the technology of the time.
WWI introduced thick steel plates for tanks to resist rifle and machine-gun fire. Later improvements focused on increasing steel hardness so panels could be thinner without losing protection, reducing weight slightly while maintaining ballistic performance.
The shift toward composites was driven by weight and mobility concerns—heavy steel limits vehicle maneuverability and fuel efficiency. As warfare evolved to include rapid deployment and air transport, lighter armour became essential.
Experiments with composites began in the 1950s–60s, with more serious adoption during the late Cold War (1970s–80s). Early composite armour used glass fibres, and later aramid fibres like Kevlar became common for better energy absorption.
Polyamide fibres like Nylon 6,6 was an early precursor to Kevlar and marked the beginning of ballistic plastics, first used in WW2 ballistic vests. The rise of plastics encouraged military projects to explore lighter alternatives to steel for improved mobility.
Composites became widely used in the late 90’s & 00’s during conflicts such as Afghanistan, where lightweight armour was critical for survivability and rapid deployment. This is where Permali became involved in ballistic protection.
Today, the debate of ballistic composites vs traditional armour reflects a major evolution in protection technology, driven by the need for lighter, more adaptable solutions without compromising safety. Permali, as a UK leader in advanced composite armour systems, has been at the forefront of this transformation for decades.
What Are Ballistic Composites?
Ballistic composites are fibre-reinforced polymer systems designed to absorb and dissipate impact energy. Common fibres include aramid (Kevlar) for high tensile strength, UHMWPE for ultra-low density and excellent fragment capture, and glass fibre for cost-effective solutions.
These composites typically consist of multiple layers (plies) of fibres combined with resin systems such as epoxy or phenolic consolidated with heat and pressure to form a laminate. The structure is engineered to spread impact forces across fibres and resin, reducing penetration and minimizing spall.
Carbon fibre is generally avoided because it has high stiffness which makes it brittle under impact—it tends to shatter rather than deform, which is unsuitable for ballistic protection.
Composites primarily capture fragments (FSP – Fragment Simulating Projectiles) and, in some cases, kinetic energy rounds. Achieving full bullet-stopping capability requires combining composites with a harder strike face materials such as steel or ceramic.
Energy absorption occurs through fibre deformation and resin bonding, which dissipates impact energy across the laminate layers.
What Is Traditional Armour?
Traditional armour materials include Rolled Homogeneous Armour (RHA) steel, aluminium alloys, and ceramics. These were widely used in systems because they were strong, simple to manufacture, and well understood.
Steel armour works well against kinetic threats like bullets but struggles against fragments and high-energy projectiles. Larger threats can penetrate and potentially shatter the steel on impact.
Adding composite backing to steel improves fragment resistance and overall survivability, creating hybrid systems that combine the strengths of both materials.
Corrosion is a major drawback of steel armour. Composites generally resist rust
Key Differences Between Ballistic Composites and Traditional Armour
Weight & Mobility
Composites are significantly lighter than steel (UHMWPE has a specific gravity <1 compared to steel at 7.8), enabling better fuel efficiency, higher payload capacity, and improved maneuverability.
Impact Resistance
Composites absorb and distribute energy differently, reducing spall in overmatch situations and improving multi-hit performance compared to steel.
Corrosion & Durability
Composites resist moisture, chemicals, and corrosion, unlike steel, which requires protective coatings.
Design Flexibility
Composites can be moulded into complex shapes, making them easier to integrate into modern vehicle designs.
Standards, Testing and Certification
STANAG 4569
NATO standard with six protection levels:
- Level 1: rifle threats (e.g., 7.62 mm ball).
- Level 2: rifles with armour-piercing tips.
- Level 3: sniper rifles (e.g., Dragunov).
- Level 4: heavy machine guns
- Levels 5–6: cannon threats
NIJ 0108.01:
U.S. standard for ballistic resistance, handgun and rifle categories
DEF STAN 93-111:
UK standard, often covering composite material and test methods.
Physical Ballistic Tests
V0 Test:
- Represents the velocity at which there is a 0% probability of penetration—every shot must be stopped.
- Used in early development to confirm armour can defeat a given threat at a set velocity.
- Setup includes a witness sheet (0.5 mm aluminium) behind the panel to detect penetration.
- Results classified as NP (No Penetration), PP (Partial Penetration), or CP (Complete Penetration).
- Multi-hit standards like AEP-55 define shot spacing for repeated impacts.
V50 Test:
- Velocity at which there is a 50% probability of penetration, identifying the transition point between success and failure.
- Multiple shots fired at varying speeds around the estimated V50 point; refined until six shots give a reliable average.
- Data used to calculate V0 for performance comparison and design improvements.
Environmental Conditioning:
- Panels may undergo temperature, humidity, and pressure tests before ballistic trials to simulate real-world conditions (e.g., desert heat, Arctic cold, high-altitude pressure changes).
- DEF-STAN 00-35 & MIL-STD-810 defines extremes for temperature, humidity, and sand/dust exposure; aerospace tests include pressure cycling to prevent delamination.
Use Cases and Applications
Defence Vehicles
Applique armour bolted onto steel/aluminium hulls to boost protection levels; spall liners added inside vehicles to reduce fragment spray.
Aerospace
Standalone composite panels for crew protection and shrapnel mitigation; UHMWPE preferred for ultra-lightweight applications critical for flight performance.
Marine/Naval
Panels for ammunition stores requiring high protection; ceramic strike faces used for high-level threats; composites prevent corrosion in harsh marine environments.
Sustainability and Lifecycle Benefits of Composite Armour
- Lower lifecycle carbon footprint due to reduced fuel consumption (lighter armour improves efficiency for land and air platforms).
- Extends vehicle service life by enabling upgrades without full redesign, reducing waste and cost.
- Composites don’t corrode like steel, reducing maintenance needs and improving durability.
- Focus is on longevity of vehicles rather than recyclability of materials.
Speak to a Permali Expert
Permali’s engineering expertise ensures that ballistic composites deliver superior weight efficiency compared to traditional armour, meeting NATO STANAG and UK DEF STAN standards. This capability positions Permali as a trusted partner for defence and aerospace programmes requiring certified, high-performance solutions.
Developed in-house by a team of material scientists and design engineers, Permali’s ballistic composite solutions are available as bespoke or standard configurations. They can be integrated directly into OEM platforms or supplied as applique upgrades and replacements, delivering a complete lifecycle service for armoured vehicles across land, sea, and air.
FAQs on Ballistic Composites vs Traditional Armour
Main materials include glass fibre, aramid (Kevlar), UHMWPE combined with epoxy or phenolic resins.
Not in absolute terms; they offer better impact resistance and weight efficiency at certain threat levels, whereas steel alone would need prohibitively thick plates.
Ballistic composites are tested through real-world ballistic trials under certification standards (V0, V50, multi-hit, environmental conditioning).
Significant weight reduction for improved mobility; ability to engineer for specific conditions (e.g., buoyancy for amphibious vehicles); enhanced protection without sacrificing speed or payload capacity.