Enhancement of an experimental method to measure accurately the evolution of forces during short-lived interactions: Application to blade-abradable material contacts in turbomachines

Thermal sprayed abradable materials are frequently used as seal linings between the casing and the blades of aircraft engines to improve safety and reduce fuel consumption. In this paper we report about the enhancements of an experimental bench developed by our group in order to fully characterize the time-evolution of the three-dimensional force occurring during high-speed interactions between an abradable coating and a titanium tip. A new stiffer testbed associated to a three-axis piezoelectric force sensor was designed to ensure a constant incursion depth during the interaction process. The newly designed device was associated with a three-dimensional implementation of the formerly developed dynamic compensation approach. As a validation of the experimental method, a measure of the wear occurring during high-speed contacts have been performed. The results have been correlated to the measured force signals showing the validity of such a full three-dimensional dynamic compensation.