PSI - Issue 39

Daniele Amato et al. / Procedia Structural Integrity 39 (2022) 582–598 Author name / Structural Integrity Procedia 00 (2019) 000–000

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crack propagation process. The starting point for this paper is the study done by Rodella et al. [19], then, the numerical analyses, performed with a different code and different algorithms, also include the nonlinear contact between the crack faces. The choice of modelling the contact between the crack surfaces may influence the crack propagation prediction, especially in those cases in which = − 1 . Nomenclature area of triangle crack length measured on the specimen free surface distance in the axial direction / crack propagation rate ( / ) Paris law constant critical correction ℎ threshold correction R-value correction axial force critical value equivalent stress intensity factor Mode I stress intensity factor Mode II stress intensity factor Mode III stress intensity factor Paris law exponent torsional moment number of steps in the mission radial polar coordinate at the crack tip

0 . 2 Δ Δ Δ Δ ℎ Δφ φ

, , yield strength

, ,

temperature volume of the triangular prism built on Cartesian coordinate at the crack tip in the propagation direction normal Cartesian coordinate at the crack tip

tangential Cartesian coordinate at the crack tip

crack increment

equivalent stress intensity factor range

Paris law constant threshold value

error in the deflection angle max nominal axial stress max nominal torsional stress

angular polar coordinate at the crack tip deflection angle