TMF panel tests: close-to-reality simulation of thermo-mechanical fatigue processes in heat-loaded walls

Kurzfassung

The concept of a Thermo-Mechanical Fatigue (TMF) - test bench is discussed in this paper. Motivation for the TMF tests are two-fold: to assess the life expectation of structures being exposed to extreme thermo-mechanical loads first on subcomponent or panel level, and to serve as validation experiment for life-prediction models. In Europe, the concept of TMF-panel testing was first very successfully applied to rocket thrust chamber structures in the frame of the Ariane 5 Flight Recovery Programme in 2003 and 2004. These encouraging results have motivated the partners DLR Lampoldshausen and EADS Astrium to jointly investigate again the TMF-bench concept with special focus on meeting relevant requirements for future liquid propulsion needs. The following key elements of a TMF test bench are presented in the paper: the TMF heating device - a diode Laser, the panel housing, the fluid, measurement and control systems as well as the tentative design of a combustion chamber type TMF panel. Furthermore, numerical analyses of this tentative TMF panel – such as a CFD as well as a thermal and structural Finite Element analysis of the core part of the TMF panel during the Laser loading are shown.