Applications of fracture mechanics in failure analysis case studies

CIM Bulletin, Vol. 78, No. 878, 1985

W.W. TENNESE, ACTA Western Metallurgical Consultants Winnipeg, Manitoba and M.N. BASSIM, Department of Mechanical Engineering, University of Manitoba, Winnipeg, Manitoba

Concepts of linear elastic fracture mechanics were applied to study two cases of failure, namely an equalizing beam from a tandem rear axle of a highway tractor unit and the main beam of a flat bed trailer. In the first case, the presence of a crack, initiated by stress corrosion cracking followed by significant fatigue crack propagation produced a state of stress which was sufficient to produce brittle failure. Calculation of the fatigue life agreed with the number of cycles that the structure experienced before final fracture. In the second case, it was demonstrated that a combination of low temperature and high loading rate was sufficient to cause brittle fracture.
Keywords: Metallurgy, Fracture mechanics, Failure analysis. Metallography, Tensile properties, Chemical analysis