Neue Auswertungsmethode zur Bestimmung der Kennwerte der Dehnungswöhlerlinie und der Spannungs‐Dehnungs‐Kurve unter Berücksichtigung der Kompatibilität

New method for evaluation of the Manson‐Coffin‐Basquin and Ramberg‐Osgood equations with respect to compatibility A new method for determining the stress‐strain and strain‐life curves for metals is presented. The method involves fitting the curve to experimental data points in a three‐dimensional strain‐stress‐life space. With the plastic part of strain, stress and fatigue life as coordinates, a straight line is used for fitting the experimental data points. The material constants are calculated directly from the directional vector R and the coordinates of the point P , which determines the fitted straight line. It is shown that the assumption of equality of the plastic and elastic components in Manson‐Coffin‐Basquin and Ramberg‐Osgood equations leads to the so called compatibility condition. This new method retains the mathematical and physical relationships between the considered curves. The results obtained from this new method using high‐strength aluminium alloys subjected to different manufacturing conditions and different test temperatures are presented. These results are compared to results obtained with a conventional method for determining the fatigue parameters.