Modal analysis and testing of rotating machines for predictive maintenance: effect of gyroscopic forces

Abstract

Through the year’s preventive maintenance, which is based on vibration measurements hasgrown in importance to reduce costs. However in industry nowadays there is still a great need for goodanalytical prediction models that describe the dynamics of rotating structures. In this paper it is first shownhow to build a model for for undamped gyroscopic systems. Secondly the model is analysed and used tomake a parametric study for the design a test rig. It is found that the third and the fourth eigenfrequencychangein function of the rotation speed due to the gyroscopic effect. Finally the experimental modal testingof rotating structures is discussed. The methods to excite a rotating structure in order to obtain the modalparameters are studied.