Very high cycle fatigue of steels under torsional loading
Abstract
In the last decades, some knowledge about the mechanisms leading to very high cycle fatigue (VHCF) failure has been accumulated. Experiments in the VHCF regime are predominantly performed under cyclic tension-compression or rotating bending loading, and fewer studies investigate the cyclic material properties in presence of mean stresses. However, the loading condition of several components in technical practice is not adequately represented by experiments performed under uniaxial loading. Coil springs or bearings, for example, are subjected to VHCF loading mainly under cyclic shear superimposed on a static mean shear load. But investigations on VHCF properties under cyclic torsional loading are very rare. It is of great technical as well as scientific interest, what damage mechanisms occur under cyclic shear loading in the VHCF regime, what is the influence of a mean shear load and what are possible differences and similarities to cyclic axial loading. The main aim of the proposed project is to investigate the VHCF properties of two steels under cyclic torsion loading at different load ratios. Experiments will be performed with a high and an intermediate strength steel associated with a different ductility. Most of the experimental work will be performed with a recently developed ultrasonic torsion fatigue testing setup. Some additional tests using a servo-hydraulic torsion fatigue test frame should allow observing possible influences of the testing technique, notably frequency influences, on the measured cyclic properties. Models for the progress of damage will be applied with the observed crack initiation and propagation behaviour at artificial defects as input. Additionally, fatigue cracks propagating under shear stress in sliding and tearing mode (Mode II & III) at very low crack growth rates will be observed. It will be attempted to find physical explanations for failure or for infinite fatigue life by identifying propagating or non-propagating conditions of short fatigue cracks subjected to cyclic shear loading. The process of fatigue damage and influences of the load ratio found under cyclic shear will be compared to cyclic axial loading. This will be done considering the mode of crack growth, i.e. crack opening mode or shear mode, which will probably depend on the magnitude of loading, the crack length and the material.
Torsion fatigue Very high cycle fatigue Load ratio Ultrasonic fatigue 17-4PH Stainless Steel
Publikationen
Influence of small defects on the uniaxial and torsional fatigue strength of 17-4PH stainless steel
Autoren: Schönbauer, BM; Mayer, H; Yanase, K; Endo, M Jahr: 2017
Journal articles
Fatigue strength of martensitic stainless steels
Autoren: Schönbauer, BM Jahr: 2018
Conference & Workshop proceedings, paper, abstract
Influence of inclusions and small defects on cyclic torsion and cyclic tension very high cycle fatigue of martensitic steels
Autoren: Schönbauer, BM; Karr, U; Fitzka, M; Mayer, H Jahr: 2018
Conference & Workshop proceedings, paper, abstract
Damage tolerance and susceptibility to inherent defects under different cyclic loading conditions
Autoren: Schönbauer BM Jahr: 2019
Conference & Workshop proceedings, paper, abstract
Effect of small defects on the fatigue strength of martensitic stainless steels
Autoren: Schonbauer, BM; Mayer, H Jahr: 2019
Journal articles
Defect tolerance of high-strength steels in the HCF and VHCF regime
Autoren: Schönbauer, BM; Yanase, K; Frondelius, T; Kuoppala, J; Kömi, J; Endo, M; Mayer, M Jahr: 2019
Conference & Workshop proceedings, paper, abstract
Effect of microstructure and cycling frequency on the torsional fatigue properties of 17-4PH stainless steel
Autoren: Schonbauer, BM; Yanase, K; Chehrehrazi, M; Endo, M; Mayer, H Jahr: 2021
Journal articles
Very High Cycle Fatigue properties of ultrahigh-strength steel - a fracture mechanics evaluation
Autoren: Schönbauer, BM Frondelius, T Ghosh, S Kömi, J Mayer, H Jahr: 2021
Conference & Workshop proceedings, paper, abstract
Influence of small defects and nonmetallic inclusions on the high and very high cycle fatigue strength of an ultrahigh-strength steel
Autoren: Schonbauer, BM; Ghosh, S; Komi, J; Frondelius, T; Mayer, H Jahr: 2021
Journal articles
Mean-stress sensitivity of an ultrahigh-strength steel under uniaxial and torsional high and very high cycle fatigue loading
Autoren: Schonbauer, BM; Ghosh, S; Karr, U; Pallaspuro, S; Komi, J; Frondelius, T; Mayer, H Jahr: 2022
Journal articles
Project staff
Bernd Schönbauer
Dipl.-Ing. Dr.techn. Bernd Schönbauer
bernd.schoenbauer@boku.ac.at
Tel: +43 1 47654-89216
Project Leader
01.04.2017 - 30.09.2021