As a result of the continuously increasing demands on lightweight engineering and the related optimal utilization of material properties, fatigue testing up to very high load cycles is increasingly coming to focus. For this reason a modern high frequency testing center for material samples and components was established at Fraunhofer IWS.
The well - selected testing machines enable fatigue testing of materials samples and components at very high test frequencies (f ≤ 20 kHz), allowing a highly accelerated determination of cyclic material characteristics. Significantly shorter test times are advantageous, for example, in the development accompanying component validation or the time-critical analysis of different development approaches. This so-called short-term diagnosis allows to provide fast data for FE calculations or to evaluate different manufacturing parameters in relative comparison. Especially in the range of very high load cycles, the state (for example microstructural change due to heat treatment) of the investigated material can decisively influence the fatigue behavior. As a result, a lifetime prediction with known regulations such as the FKM guideline – Computational fatigue analysis for machine components, may be too conservative or the strength capacity of the material is overestimated. For the best possible utilization of the load capacity of materials and components in the sense of a resource-efficient design or a targeted lightweight construction strategy, experimental fatigue testing is strongly recommended.
To determine the material and component reliability, the IWS high frequency test laboratory provides, among others, ultrasonic fatigue test systems (f ≈ 20 kHz) and state-of-the-art electromagnetic resonance pulsators (f ≤ 1,000 Hz). Thus, the best test method can always be used for the respective application.
- Significantly shorter test times for component validation during development and time-critical analysis of pre-series, for quality assurance or for damage analysis
- Short-term diagnostics to determine the failure-relevant defect type and size (for example: castings, additively manufactured components, joint connections, ...)
- Determination of surface strain using extensometer, strain gauges and digital image correlation