PSI - Issue 18

Markus Berchtold et al. / Procedia Structural Integrity 18 (2019) 532–537 Markus Berchtold/ Structural Integrity Procedia 00 (2019) 000–000

536

5

Table 2. Temperature recordings of high strength bolts during fatigue

Material

Specimen

Testing condition

Frequency

Load amplitude

Temperature

Gauge diam.

Cycle to failure 134’322

steel

Constant load Mean load 37.9kN

1006 Hz

8.0 kN

20.4°C

flange head bolt

M9x1.25

7.5 kN

20.5°C

213’371

7.0 kN

20.4°C

180’707

4. Summary and Outlook The RUMUL GIGAFORTE is an efficient tool for testing very high number of load cycles in a reasonable time. Common specimen types and sizes can be used. Depending on material and load the specimen may heat up. The heating is usually low or moderate and can be mitigated with compressed air cooling, continuous testing is possible. The possibility to test on 1000Hz testing frequency may help to further evaluate frequency effects and further enhance the confidence on fatigue data in the high and very high cycle regime. Next steps  More HCF test (10 6 cycles and less) on high strength bolts for evaluation of the fatigue life results.  VHCF testing (10 9 cycles and more) on fibre-reinforced composite materials cooperation with TU Dortmund/ Germany. References [1] International Journal of Fatigue 93 (2016) 215. In Memoriam Claude Bathias 1938–2015, HaëlMughrabi, Professor Emeritus of Materials Science and Engineering, University of Erlangen-Nürnberg, 91058 Erlangen, Germany [2] Einfluss der Prüffrequenz auf die Rissinitiierung und das Ermüdungsrisswachstum im HCF/VHCF-Bereich am Beispiel des Stahls 1.4301, Tagung Werkstoffprüfung 2016, M. Zimmermann et al. Institut für Werkstoffwissenschaft, Technische Universität Dresden [3] Frequency effect and influence of testing technique on the fatigue behaviour of quenched and tempered steel and aluminium alloy. International Journal of Fatigue 93 (2016) 224–231 N. Schneider et al. State Material Testing Institute and Institute for Materials Technology, TechnischeUniversität Darmstadt, Grafenstr. 2, 64283 Darmstadt, Germany [4] Neue Ansätze für eine Schädigungsenergiehypothese auf der Basis thermischer Messungen, 6. Sitzung des DVM Arbeitskreises Betriebsfestigkeit in Darmstadt, Klaus Stärk. [5] Influence of loading frequency and role of surface micro-defects on fatigue behaviour of metastable austenitic stainless steel AISI 304. D.F. Pessoa et. al. Fraunhofer-Institut für Werkstoff -und Strahltechnik IWS, 01277 Dresden, Germany and Institut für Werkstoffwissenschaft, Technische Universität Dresden, 01069 Dresden, Germany. [6] The effect of different microstructures by heat treatment on the VHCF properties of low carbon steels. A. Giertler, K. Koschella, U. Krupp, Hochschule Osnabrück - University of Applied Sciences, Germany