Fasteners play a critical role in the safety and durability of aircraft. They hold pieces together and help assemble aerostructures such as the fuselage, wings, empennage, nose, tower, nacelle, and flight control surfaces.
They’re made from different materials to meet specific application requirements. This means choosing the right material is a crucial design consideration for engineers.
Material
Choosing the right material for fasteners is essential. It can impact the strength of a bolt, the durability of the bolt in its final application, and its ability to perform the intended function.
Metals are used to create a wide range of fasteners. Steel and aluminum are among the most common materials.
Steel is a popular choice because of its high strength and corrosion resistance, although it does require certain treatments to make it more resistant to heat and rust. Aluminium is another popular choice because it is lightweight and strong.
Design
Aircraft fasteners are a critical part of every aircraft’s design and play an important role in the safety and durability of the airplane. They have many designs and properties, making them perfect for various applications.
Aerospace fasteners are usually made from steel, aluminum, and titanium. These metals offer great strength-to-weight ratio, corrosion resistance, and durability.
However, choosing the right fastener material for an aerospace application is important. Certain materials cannot withstand extreme environments, while others can.
There are many factors to consider when selecting the perfect fastener for your aircraft project, including weight, inspectability, tooling requirements, aerodynamic smoothness, access, and corrosion protection. In addition, there are options for optional surface finishes, which can enhance fastener features like corrosion resistance, high-temperature resistance, wet sealing, and aesthetics.
Cycle Life
Aerospace fasteners – bolts, studs, and rivets – are among the most critical components to construct large aircraft. They must withstand repeated pressure and temperature cycles, variations in dynamic loads, and high vibration levels.
Even with their importance, aerospace fasteners may only succeed if they are manufactured correctly or tested to withstand the stresses of flight operations. This can result in poor performance, failure of structural components, or even the risk of a catastrophic accident.
This is where the life cycle of an aircraft comes in handy. For example, if an aircraft is subject to frequent pressurization cycles during flight, its fastener holes will likely crack over time due to metal fatigue.
If the cracks exceed a specified size, they will likely cause structural damage and require expensive repairs or replacement. This can have a negative impact on safety, operational readiness, and life-cycle costs. It’s for this reason that it is vital for the right checks to be done during every pre and post flight stage for an aircraft. Using sophisticated ground support tools from a reputable provider such as tronair can greatly improve both the quality and range of checks done, this ensures that no debilitated parts are ignored and the correct repairs or replacements are provided to an aircraft before a serious accident can occur.
Environment
The environment impacts the safety and durability of aircraft in many ways. This includes everything from temperature fluctuations to the type of material used in the fasteners and how they are treated and maintained throughout their lifespan.
For example, aerospace fasteners are exposed to loads from towing, flight operations, wind gusts, and pressurization, to name a few. These loads will transfer through the joint, affecting its strength and durability.
In addition, aircraft fasteners are often placed in critical application areas that must be protected from environmental corrosion. This creates a need for coatings that can act against stress corrosion, electrochemical corrosion, fatigue corrosion, chemical and atmospheric corrosion and withstand temperature extremes to protect the fasteners from damage and retain their strength.