The fatigue life estimation of elements with circumferential notch under uniaxial state of loading

摘要

The complex geometry of machine elements contains the stress concentrators which are sources of fatigue cracks creation caused by variable loading while the device is operating. For fatigue life estimation it is necessary to identify the strain and stress distribution at the notch tip. In the paper the authors proposed an algorithm for determination of elastic-plastic strain and stress at the circumferential notch tip under uniaxial tension. The obtained results of calculated strain and stress distribution were compared with those obtained from numerical calculations using the ANSYS software. The calculations were performed for three materials with different mechanical properties. The fatigue life estimation was done for one of the analyzed material with the application of the critical plane approach. The results were compared with those from the fatigue tests of smooth and notched specimens made of low carbon steel St3S. Fatigue properties of St3S steel were determined from the tests performed under the control of strain and strain energy density parameter.