One could make the case that the biggest advantage aerospace composites have is their strength-to-weight ratio. Composites weigh considerably less than steel and aluminum but are stronger than both. But in military applications, composites have something else to offer – built-in stealth capabilities.
The relationship between aerospace composites and stealth is a multifaceted one. Different composites contribute to stealth in different ways. When you look at the big picture, however, it is clear that the stealth capabilities of modern military vehicles simply would not be possible without composites.
For the remainder of this post, we will focus primarily on aircraft. Aerospace composites contribute to stealth capabilities in the following ways:
Radar absorption is critical to stealth capabilities. If an aircraft cannot be picked up by ground radar, it is harder to detect. Aerospace engineers rely on composite materials to address this.
Composites can be engineered to absorb radar waves, thereby significantly reducing an aircraft’s radar cross-section. What cannot be absorbed can be deflected away from radar receivers to make a stealth aircraft nearly invisible.
Achieving maximum stealth capabilities relies heavily on design features. And in any form of aircraft design, engineers are limited by the materials they work with. Aerospace composites have a lot to offer in terms of structural integration.
The B-2 bomber is a perfect example of how structural integration benefits stealth capabilities. A significant portion of the bomber’s structure can be constructed with composite materials. This allows engineers to design more stealth features into the plane without having to worry about weight considerations.
Speaking of weight considerations, they do play a role in stealth capabilities. Lighter aircraft are faster and easier to maneuver. Both properties make an aircraft more stealthy. It is a lot like watching cars on a racetrack. The faster and more maneuverable they are, the harder they are to follow with the naked eye. It’s a lot easier to watch a car traveling in a straight line at just 10 mph.
Maximizing both radar absorption and deflection is often a matter of designing unconventional structures. Let us go back to the B-2 bomber for evidence. This particular aircraft looks nothing like a traditional plane. In fact, it is often referred to as ‘one big wing’ rather than a traditional aircraft.
Its design would not be possible with aluminum and steel. But with aerospace composites, the bomber’s design represents just another day in the office among aerospace designers and engineers. They can do what they do because they have access to advanced composite materials.
How an aircraft interacts with radar waves influences its visibility. Fortunately, composites can be engineered to demonstrate specific electromagnetic properties. These properties can have a considerable influence on how an aircraft interacts with radar, thus improving stealth capabilities.
The more control engineers have over electromagnetic properties, the more radar resistance they can build into their designs. This has composite manufacturers constantly looking for new ways to improve electromagnetic properties.
Finally, one of the most exciting areas of aerospace development right now is multispectral stealth. Engineers are working on carbon-based composites with the potential to offer stealth across multiple spectrums – these include radar, visual, and infrared.
Stealth has been a key component of warfare for millennia. But in more recent generations, our understanding of stealth has been enhanced by new technologies and materials. The stealth we enjoy today is due largely to the introduction of advanced composites. And where aircraft are concerned, advanced aerospace composites are the name of the game.
