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In this paper crack paths have been studied in sharply V-notchedspecimens subjected to in-phase mode I and II loadings. Specimen geometries allowedus to analyse the cracking behaviour in the presence of different ratios between mode Iand II loadings. The investigated fatigue lives ranged from 103 up to 2· 106 cycles tofailure. By studying the stress field along the measured crack paths, it has beenobserved that the role played by the shear stress was crucial up to a distance from thenotch tip equal to L/2. Over this distance value, crack propagation was mainly mode Igoverned and the shear stress importance seemed to become secondary.