Experimental Evidence of Specimen-Size Effects on EN-AW6082 Aluminum Alloy in VHCF Regime

The present paper investigates the influence of specimen size EN-AW6082 wrought aluminium alloy subjected to very high cycle fatigue (VHCF) tests. hourglass specimens were tested under fully reversed loading condition, up 109 cycles, by means ultrasonic testing machine developed Italsigma® (Italy). Three groups considered, with a diameter in middle cross-section ranging from 3 mm 12 mm. stress field was determined numerically and strain gauge measurements correspondence surface. dispersion experimental results has been accounted for, data are reported P-S-N diagrams. decrease resistance increasing is evident. Theoretical explanation for observed specimen-size effect provided, based on Fractal Geometry concepts, allowing obtain scale independent P-S*-N curves. life expectation VHCF regime full-scale components rather overestimated if it assessed only standard small diameter. Experimental tests carried out larger specimens, proper extrapolation, required assure safe structural design.