Use of Linear Elastic Fracture Mechanics in the In-service Fracture Analysis of Structural Components

Abstract

AbstractThe proposed failure analysis procedure requires six important steps which are a combination of the fractographic analysis and the application of approximation method based on linear elastic fracture mechanics. This procedure was applied to an in-service failure of an anchor bar of a high-voltage transmission line tower.Microscopic observations of the fracture surface indicated multiple crack initiation sites and brittle intergranular features mixed with transgranular cleavage fracture. This is probably caused by the hydrogen embrittlement which produced a weakening of the material properties at the toe of the fillet which could be assumed to produce a narrow axisymmetric crack at the fillet toe. The remote stress needed to produce failure was analysed for different crack sizes and different applied stress intensity factor, K I. The fracture toughness K IC was insufficient for this material. Higher fracture toughness would have been required or the problem would need to have been detected by quali...