AerospaceMaterialsFailureModesInstructorNotes.docVIP

Failure Modes of Aerospace Materials Instructor Notes Introduction These instructor notes contain commentary for each of the accompanying slideshow presentation. These notes are followed with related student activities and references. Each presentation slide is numbered in the lower left-hand corner to facilitate matching the sequence with these notes. Slide 1 Title Slide- Aerospace Materials Failure Modes Slide 2 Questions What types of materials are used in aircraft? How do aircraft structural materials fail? How do materials failure modes affect aircraft? What do these material failure modes look like? What are the root causes of these failures? Slide 3 But first, why are we focusing on failure? Simply, this is what we are trying to prevent. There are far greater consequences of failure for aircraft than for ground based equipment. Aircraft must be light, so they cannot be made any heavier for strength than needed. Aircraft must endure thousands of hours of turbulence that vibrates and flexes the structure. Aircraft must endure thousands of landings which place high loads on the structure. Because of these conditions and others, the materials are used to highest potential, but failure must be anticipated and minimized. Slide 4 What types of materials are used in aircraft? Metals Aluminum- Very common, traditional aircraft material, light, strong, good corrosion resistance Steel/Stainless Steel- Very high strength, for highly loaded components Titanium- Roughly the strength of steel but 2/3 the weight Magnesium- Similar to aluminum in properties but even lighter Superalloys- Nickel based high temperature resistant alloys for use in engines Ceramics- Combinations of metals and non-metals, strong but brittle, high temperature resistance Plastics/Elastomers Aircraft interiors, tires, sealants, adhesives Composites Rapid growth in use of complex engineered materials to replace much of the traditional materials Eac