To date, aviation remains the youngest mode of transport. Even those who are not at all interested in aircraft know that when attaching the fuselage of metal birds, they do not use welding, screws, and even less carpenter's nails, but rivets. But did you have to think about why the rivet was chosen as the fastener for the connection?
It is quite obvious that of all the methods of joining metal parts, welding has been and remains one of the best, most economical and at the same time reliable. Or is it still not? In fact, when it comes to the aerospace industry, when it comes to welding, everything immediately becomes not as simple as we would like. And all because, with apparent reliability, welding has one serious drawback.
How does welding work? If we describe this process in broad strokes, then something like this: before joining, metal parts are heated to a melting temperature, which leads to deformation, followed by solidification. The problem is that with this method of joining two materials, excessive mechanical stress is formed, which in the future can develop into “metal fatigue”. All this is not too scary for fixed structures. However, if the product is constantly moving and regularly exposed to long-term external loads, deformation and destruction of the material can occur.
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So it turns out that the use of welding in aircraft is contraindicated, since their fuselage is constantly under the influence of critical loads. A welded aircraft most likely will not survive even the first takeoff or drawdown. However, even if the welded machine somehow miraculously survived in the sky, then its fuselage most likely would not have survived the turbulence zone. Therefore, for safety reasons, rivets have been used in the construction of aircraft for more than a century.
Unlike welding, rivets are much better able to withstand the two main types of stress that the aircraft fuselage constantly encounters - vibration loads and shock loads. Most often in aviation, overlapping materials are used with the chain structure of the rivet row. In addition, the rivet seam in aircraft is covered with a special protective compound to ensure the tightness of the structure.
If you want to know even more interesting things, then you should read about how much do different countries cost their best fighter planes.
Source: https://novate.ru/blogs/010522/62870/