A Method for Flutter Detection by Infrared Imaging

ABSTRACT: The performance enhancement of aircraft coupled with the development of increasingly lightweight and flexible materials has led designers to use smaller structural safety factors along the time, which can make aerodynamic surfaces more susceptible to aeroelastic phenomena, including flutter. This kind of occurrence must be carefully investigated by ground and flight tests during aircraft development and certification, which requires suitable instrumentation in order to predict the occurrence of unwanted vibrations. The sensors in this kind of application must be less intrusive as possible, in order to not modify the dynamic or aerodynamic behavior of the system. This work proposes the use of infrared imaging as a tool for flutter detection, analyzing the suitability of the technique for this application. For this purpose, a literature review was performed by presenting infrared technology concepts; then, some preliminary tests were performed in a structure to predict flutter characteristics, and finally wind tunnel tests were executed in the same structure, validating this technique and highlighting its positive points and points that need improvement.