Numerical-Experimental Confrontation in the Simulation of Tool/Abradable Material Interaction

In turbomachinery, depositing abradable coatings along the circonference of casings is recognized as a robust solution which combines the adjustment of operating clearances with the reduction of nonrepairable damages potentially affecting the rotating blades. Accordingly, the modeling of the removal process experienced by these materials is of growing industrial importance. Based on a numerical strategy detailed in a previous publication by the authors, the present study aims at describing the mechanical behavior of abradable coatings used within turbomachines in the context of translational high-speed interactions with a rigid tool. The developed plastic constitutive law macroscopically capturing the abradable material removal is first enriched to account for its strain rate dependence. Then, a sensitivity analysis with respect to a few parameters of interest is conducted and calibration of the numerical investigation with existing experimental data validates the proposed approach. Finally, the strain-rate dependence of the viscoplastic law implemented within a full numerical three-dimensional rotor/stator interaction is addressed. Results reveal that viscoplastic terms have minor effects in turbomachinery interactions.