Issue 41

A. S. Cruces et alii, Frattura ed Integrità Strutturale, 41 (2017) 54-61; DOI: 10.3221/IGF-ESIS.41.08 60 Figure 6 : Predicted vs. experimental life for St52-3N using Fatemi II model and Sandip model. C ONCLUSION wo recently developed fatigue theories have been studied on experimental data. The experimental data were acquired on biaxial tests combining tension-compression and torsion under proportional load. The two fatigue theories were based on the critical plane approach. One of them is an enhanced formulation of the Fatemi-Socie damage parameter. The other theory uses the product of the normal and the shear stress at the critical plane. Both theories provided an overall good prediction for the loading cases analyzed. While the new Fatemi-Socie damage parameter tended to overestimate the fatigue life preditions, the Suman-Kallmeyer tended to underestimate the life preditions. A CKNOWLEDGEMENTS uthors would like to acknowledge financial support of Junta de Andalucía thru Proyectos de Excelencia grant reference TEP-3244, Campus de Excelencia Internacional del Mar (CEIMAR) and Ministerio de Economía y Competitividad thru grant reference MAT2016-76951-C2-2-P. R EFERENCES [1] Christopher CJ, Lu Y, Patterson EA. Local crack plasticity and its influences on the global elastic stress field. Int J Fatigue 2013;46:4–15. [2] Zanganeh M, Lopez-Crespo P, Tai YH, Yates JR. Locating the crack tip using displacement field data: a comparative study. Strain 2013;49:102–15. [3] Branco R, Antunes FV. Finite element modelling and analysis of crack shape evolution in mode-I fatigue Middle Cracked Tension specimens. Eng Fract Mech 2008;75:3020–37. doi:10.1016/j.engfracmech.2007.12.012. [4] Lopez-Crespo P, Pommier S. Numerical analysis of crack tip plasticity and history effects under mixed mode conditions. J Solid Mech Mater Eng 2008;2:1567–76. [5] Rodopoulos CA. Fatigue Damage from Surface to Bulk. In: Sih GC, editor. Multiscale Fatigue Crack Initiat. Propag. Eng. Mater. Struct. Integr. Microstruct. Worthiness Fatigue Crack Growth Behav. Small Large Bodies, Dordrecht: Springer Netherlands; 2008, p. 113–31. doi:10.1007/978-1-4020-8520-8_6. T A