Author(s): Correia, J. A .F. O. ; De Jesus, A. M. P. ; Calcada, R. ; Pedrosa, B. ; Rebelo, C. ; Silva, Luís Simões da
Date: 2017
Persistent ID: https://hdl.handle.net/10316/108202
Origin: Estudo Geral - Universidade de Coimbra
Subject(s): Fatigue Crack Growth; Strain Energy; Unigrow Model; Pressure Vessel Steel
Fatigue crack growth (FCG) rates have traditionally been formulated from fracture mechanics, whereas fatigue crack initiation has been empirically described using stress-life or strain-life methods. More recently, there has been efforts towards the use of the local stress-strain and similitude concepts to formulate fatigue crack growth rates. A new model has been developed which derives stress-life, strain-life and fatigue crack growth rates from strain energy density concepts. This new model has the advantage to predict an intrinsic stress ratio effect of the form σar=(σamp)γ·(σmax )(1-γ), which is dependent on the cyclic stress-strain behaviour of the material. This new fatigue crack propagation model was proposed by Huffman based on Walkerlike strain-life relation. This model is applied to FCG data available for the P355NL1 pressure vessel steel. A comparison of the experimental results and the Huffman crack propagation model is made.
