Review of experiences in Helicopter Vibration Testing.

Abstract

Vibrations are a major problem in helicopter structural dynamics due to the complex airloads introduced into the aircraft by the rotor system. Experimental and theoretical investigations are required to fulfill future demands of vibration levels. For more than 15 years DLR has been involved in helicopter ground vibration testing. The present report summarizes the experiences and describes test methods and test facilities. Illustrative test cases of actual helicopter developments are presented. The importance of correlating experimental and theoretical results is emphasized. Recommendations are given to improve the test performance with regard to time saving and measurement quality. The work was performed within the activities of the GARTEUR Helicopter action Group "Helicopter Vibration Prediction and Methodology".