Entwicklung einer Prüfapparatur für die hochfrequente Ermüdungsprüfung von dünnwandigen Strukturen

Translated title of the contribution: Development of a test equipment for high-frequency fatigue testing of thin-walled structures

Michael Tillmanns

Research output: ThesisMaster's Thesis


Due to the lack of suitable testing methods with sufficiently high testing frequencies, the fatigue strength of materials at very high numbers of cycles of more than 10^7 has been insufficiently researched. This work deals with the development of a high-frequency testing methodology for the investigation of the fatigue strength of thin-walled structures. As a fundamental principle, the increase in amplitude in case of an externally excited oscillation of a spring-mass-system in resonance is used. For the development of the thin-walled, vibration-capable specimen geometry, a parameter study is carried out with the aid of modal analysis and frequency response analysis. As a result, the notch wall thickness followed by the notch radius are the most important characteristics regarding the influence on the natural frequency and the stress distribution of the specimen. The rotationally symmetrical specimen geometry is designed in such a way that its natural frequency for the first axially oscillating mode is in the range of 1000 Hz. It has a diameter of 30 mm and a radially variable thickness with a specific testing cross section of only 0.1 mm wall thickness. The thin-walled structure is set into resonance oscillation by an electrodynamic shaker, causing the testing cross section of the specimen to experience very high stresses, which can be up to 600 MPa, depending on the excitation acceleration of the shaker. As a link between the shaker and the specimen, six implementable concepts for a testing equipment are developed, in which the specimen is clamped by different designs of clamping nut, disc spring, clamping ring and clamping set. The most suitable concept is then determined by using an elaborated evaluation matrix. This concept for the testing equipment is developed up to production readiness and is designed in such a way that the specimen can be mounted precisely, stress-free and reproducibly. To validate the simulation results, the specimen and the testing equipment are manufactured and tests on vibration behaviour are carried out. The testing equipment shows a high vibration stiffness, as the transmissibility of the testing equipment determined with acceleration sensors is close to the value 1. The tests show a distinctive resonance behaviour of the specimen, whereby a rise in the resonance frequency with increasing excitation acceleration is detected. The vibration of the specimen measured by a laser vibrometer is harmonic and without any disturbances or distortions. The suitability of the testing arrangement for high-frequency fatigue testing of thin-walled structures is thus confirmed.
Translated title of the contributionDevelopment of a test equipment for high-frequency fatigue testing of thin-walled structures
Original languageGerman
Awarding Institution
  • Montanuniversität
  • Winter, Gerhard, Co-Supervisor (internal)
  • Himmelbauer, Florian, Co-Supervisor (internal)
  • Grün, Florian, Supervisor (internal)
Publication statusPublished - 2020

Bibliographical note

embargoed until 02-06-2025


  • fatigue strength
  • testing methodology
  • shaker
  • high-frequency

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