Project aims
The project plans to deliver significant technical innovations in following major topics to ensure world-leading competencies in aero engine and aircraft manufacturing sector for Europe:
- Improvement and development of advanced standard and non-standard cutting-edge TMF experimental methods and harmonisation of the test methods to enable standardisation across the field by performing comprehensive studies into the phenomena for a range of representative parts,
- Advanced metallurgical assessment of structural disc alloys taking into account the effect of multiple critical variables (e.g. R-ratio, phase, environment, dwell) to determine active damage mechanisms that control the life under TMF operating conditions, and
- Physically based coupled models, with experimental validation, capable of predicting TMF initiation and propagation lives of components subjected to complex engine cycles and suitable for implementation in the computer programmes used to predict component lives.
Development of a TMF crack propagation experimental method is still in its infancy, as only a handful of high temperature TMF crack propagation (CP) testing facilities exist worldwide (including LiU, SU and UNOTT). Further, Rolls-Royce MTOC, DevTMF partners and other groups have formed a Working Group to develop a new Code of Practice for stress/load controlled TMF experimental initiation method as the procedural guidelines are still lacking. Therefore, significant innovations are required and will be delivered during the project in terms of the TMF experimental methods. Robust, statistical assessed and easily calibrated predictive TMF crack initiation and propagation models consistent with the damage mechanisms and sensitive to the fatigue damage process for life assessment of critical components developed in DevTMF will provide accurate extrapolations from a known set of results.
The project will take the above-described technologies to TRL5. Two business opportunities are addressed by this work: (i) at the end of the project the materials understanding and lifing models will be used to optimise/uprate the performance of existing individual aero engine components and (ii) over a longer timescale influence the development of new disc alloys and ultra efficient future designs (Advance, Ultrafan). The developed TMF technologies will enable industrial aero gas turbines used for aero engines to be operated at higher temperatures and pressures, improving their efficiency and reducing fuel consumption (by 1%) and CO2 emissions. Hence improved competitiveness and marker share.
Project objectives
The main aim of the DevTMF project is to characterise TMF behaviour of two structural alloys of interest to allow for more accurate prediction of design lives of present and future gas turbine components. The ultimate goal is to enable further increase of operation and service life, which will subsequently provide environmental and economic benefits to the European gas turbine industry and Europe. To reach the aim of the project, the specific objectives are:
- To validate TMF crack initiation (CI) and crack propagation (CP) test methods,
- To perform conventional isothermal and advanced TMF CI and CP specimen tests of the chosen disc alloys,
- To characterise the TMF behaviour and corresponding damage mechanisms in the alloys,
- To develop advanced TMF CI and CP prediction models, and
- To validate the predictive models by component representative TMF CI and CP tests.