Multiaxiale Ermüdung und Reibermüdung bei Hochtemperatur unter korrosiver Atmosphäre in einem MTC-Prüfstand am DLR

At the DLR Institute of Test and Simulation for Gas Turbines in Augsburg, novel test facilities have been developed and built that enable the simultaneous application of severe mechanical, thermal and chemical loads – the so called MTC test stands. Only recently, the biaxial test stand has been brought in service, enabling our understanding of multiaxial fatigue phenomena and fretting fatigue damage in aircraft components in a test environment that comes close to conditions encountered in aeroengines. In this work, the biaxial test stand and its complex components are presented in detail. The test stand is unique not only as a result of the complex loadings (mechanical, thermal, chemical), but also thanks to the use of newest technological developments: Whilst the material samples to be tested are optically accessible for contact-free strain measurement, they can be heated up to temperatures of more than 1200°C making use of a specially developed laser heating system. Using state-of-the-art hardware and software solutions that bring digital imaging correlation and laser scanning technology to their highest potential, it is possible to obtain high quality strain field data whilst ensuring a homogeneous surface temperature required for material testing according to norms, standards and customer requirements.