Haoran Wu 1,2, Zhenjie Teng 1,2, Christian Boller 1, Peter Starke 2
1 Chair of Non-Destructive Testing and Quality Assurance, Saarland University, D-66125 Saarbrücken, Germany
2 Materials Science and Materials Testing, University of Applied Sciences Kaiserslautern, D-67659 Kaiserslautern, Germany
The comprehensive understanding of fatigue mechanisms and damage evolution processes of metallic materials requires a reliable characterization of the microstructure, which changes steadily due to the applied cyclic loading during fatigue processes. Since the linear damage accumulation models cannot fully represent the realistic cases, it is expected, that the advanced fatigue life evaluation methods should provide more fatigue parameters than by conventional methods.
In this regard, different short-time procedures have been developed during the last years by the authors by taking the fact into account, that the nonlinearity of the elastic-plastic behaviour of metallic materials could be characterized more appropriately by combining the non-destructive testing (NDT) methods and the digitalization of the measurement as well as signal processing techniques. Thus, the improved gain from fatigue data can be used to reduce the experimental effort and costs significantly.
SteBLife is one of these new short-time methods showing new possibilities in rapid fatigue data evaluation, whereby only three to five tests are required to determine a complete S-N-curve including mean and/or complete scatter bands. If just a trend S-N-curve is desirable, the number of tests could even be reduced down to one single test.
Beside the reduction in time and cost for experimentation, SteBLife offers also the possibility to take advantage of the diverse fatigue-related parameters, in order to transform potentially the traditional S-N-curves into multidimensional datasets to be used as input for different structural simulation or assessment tasks.