Fatigue Behavior of Thin Sheets of DP590 Dual-Phase Steel

Fatigue properties of 1.6 mm thick dual-phase steel (DP590) sheet have been determined by carrying out axial fatigue tests in load controlled mode at different stress ratios for both smooth specimens and specimens with hole at center. The presence of hole at center of the specimen significantly reduces the fatigue strength. When the fatigue data points are plotted in the Haig-Soderberg diagram, they follow a parabolic relationship for smooth specimens represented by Gerber line and a straight line relationship for the specimens with holes at its center represented by Goodman line. Master Diagram which acts as a guide for the fatigue design is also drawn for both smooth specimens and specimens with holes.