Title: Fatigue Performance Under Rotational Bending and Axial Performance of 1018 Steel: Effect of Surface Roughness and Failure

Authors: Brennan Hume, Akawut Siriruk, Dayakar Penumadu

DOI:

Abstract: 1018 Steel is a vital alloy used in the automotive, aerospace, and defense industries due to its exceptional mechanical properties. Understanding fatigue properties is crucial for developing process-structure-property relationships and evaluating failure mechanisms. Rotational bending fatigue is preferred over axial fatigue testing for its excellent efficiency in high-cycle loading applications. This study aims to evaluate rotational bending fatigue behavior for 1018 steel to expedite high-cycle fatigue data collection. Hourglass-shaped specimens, prepared according to the rotating bar fatigue testing standard ISO 1143, are subjected to rotational bending fatigue tests. The stress fatigue life cycle data are then compared to benchmark axial fatigue data for 1018 steel. This study analysis reveals that axial fatigue strength is consistently lower than rotational bending strength for a given fatigue life. This discrepancy stems from differing stress distributions: axial tests subject the entire cross-section to maximum stress, while rotational bending concentrates maximum stress at the surface. The established quantitative relationship allows for faster, more efficient rotational bending tests to accurately supplement and improve data collection from axial fatigue performance, significantly accelerating material characterization.

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Conference: SAMPE 2026

Publication Date: 2026/04/27

SKU: 86

Pages: 13

Price: $26.00