Effects of non-proportionality and tension–compression asymmetry on the fatigue life prediction of equivalent stress criteria

authored by

Michael Kuhn, Nikolas Manousides, Alexandros Antoniou, Claudio Balzani

Abstract

Biaxial tension/compression–torsion fatigue tests with varying levels of non-proportionality were performed employing a structural adhesive designed for wind turbine rotor blades. The cycles to failure were found to be independent of the level of non-proportionality. It is demonstrated that numerical fatigue life predictions via rainflow-counted equivalent stress histories are not able to replicate these experimental observations and overestimate the fatigue life up to a hundredfold. The tension–compression asymmetry of the adhesive resulted in significant damage prediction differences depending on the stress space representation of the Haigh diagram. If not properly taken care of, the asymmetry will also lead to non-conservative results. While demonstrated with a short fiber-reinforced adhesive, the results can be transferred to other materials.

Organisation(s)

Institute of Wind Energy Systems

External Organisation(s)

Fraunhofer Institute for Wind Energy Systems (IWES)

Type

Article

Journal

Fatigue and Fracture of Engineering Materials and Structures

Volume

46

Pages

3161-3178

No. of pages

18

ISSN

8756-758X

Publication date

10.08.2023

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Materials Science(all), Mechanics of Materials, Mechanical Engineering

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy

Electronic version(s)

https://doi.org/10.1111/ffe.14065 (Access: Open)