Testing Metals and Advanced Materials in Aerospace
Expert testing support provided to the aerospace sector includes developing innovative and bespoke fatigue testing solutions on materials varying from base metal alloys to highly-engineered reinforced composites.
Since the beginning of human aviation history, failures caused by engineering fatigue have been a common cause of structural failures. The first recorded mention of fatigue was in 1837 by Wilhelm Albert who observed fatigue damage in conveyor chains in mines. Five years later, the cause of the fatal Versailles train crash in 1842 was attributed to metal fatigue in a wheel axle. Then, in the 1950s, three de Havilland Comets crashed due to catastrophic decompression after a fatigue crack grew from the corner of a punch riveted square window in the fuselage. All this led to systematic research into metal fatigue and its recognition as a major part of component life.
Engineering fatigue is the repeated application of stress or strain on a component at levels lower than what would normally cause any permanent deformation or failure. Each application and removal of the applied force is called a cycle. Fatigue damage is built up per cycle on a microscopic level within a material, eventually forming short cracks that will lead to failure, and is the most common mechanism for component failure. Fatigue life predictions are calculated through a combination of materials testing and computer modeling and will define critical component inspection and service periods.