FATIGUE – FAILURES VARIOUS MECHANICAL COMPONENTS Cracks in bicycle frameHelical gear Spring Steering arm Pedal Stub axleBoltShaft - torsion Source: The Open University -
AEROSPACE INDUSTRY December 19, 2005, off Miami Beach, Florida, Grumman G73T Turbo Mallard seaplane Fatigue cracks in the right wing. Lading gear fatigue failure Aloha Airlines Flight April 28, 1988 Cracks in the fuselage
SHIPS USS Tanker ship fractured in January 1943 Liberty ship - USS Carlos Carillo 2,751 built between Built from welded sections 1500 instances of significant brittle fractures 19 ships broke in half without warning Steel embrittlement Cracks initiated from stress concentrators Crack propagation along weld lines (source:
STRESS ANALYSIS – FINITE ELEMENT METHOD Airplane wing spar
NOTCHED SPECIMENS DUCTILE FRACTURE STUDIES Finite element analyses Scanning electron microscopy