Untersuchung verschiedener Vergleichsspannungshypothesen im Kontext der Dauerfestigkeit einsatzgehärteter Wellen

Research output: Contribution to journalResearch articleContributedpeer-review



In general, case-hardened components are assumed to have a brittle edge area and a ductile core. An alternating strength ratio of τWW=1 characterises an ideally brittle material, while ductile behaviour is characterised by τWW=1/3. Regarding the design of shafts, knowledge of the alternating strength ratio is a prerequisite for the correct selection and application of an equivalent stress hypothesis. This is used to calculate a scalar characteristic stress value for multi-axial or non-proportional stress conditions. In practice, however, the required cyclic material parameters are often not available, which is why the material behaviour to be assumed especially for case-hardened shafts remains unknown. The publication first provides an overview of equivalent stress hypotheses used in practice. In order to investigate the potential of the various hypotheses in the context of case-hardened surface layers, fatigue strength tests from the literature are investigated. The test data is used to recalculate the theoretical fatigue strengths which are then contrasted to the corresponding experimental results. A comparison of the equivalent stress hypotheses under variation of the alternating strength ratio shows that a conservative estimation of the safety factor is possible using the distortion energy criterion (also known as von Mises criterion) with less scatter than applying the normal stress criterion. Thus, the assumption of ductile behaviour and consequently the use of an alternating strength ratio of τWW≈1/3 also appears possible for case-hardened surface layers.

Translated title of the contribution
Investigation of various equivalent stress hypotheses regarding the high-cycle fatigue strength of case-hardened shafts


Original languageGerman
Article number12
JournalForschung im Ingenieurwesen/Engineering Research
Issue number1
Publication statusPublished - 4 Apr 2024


TitleDresden Colloquium on Machine Elements 2024
Abbreviated titleDMK 2024
Duration14 - 15 May 2024
Degree of recognitionNational event
LocationHYPERION Hotel Dresden am Schloss

External IDs

ORCID /0000-0002-0517-7425/work/157317328
ORCID /0009-0001-3407-9787/work/157317456
Scopus 85189929349


Subject groups, research areas, subject areas according to Destatis

ASJC Scopus subject areas