LAUSR

Abstract Identification of torsional receptances of shaft structures has been a challenge. This paper presents a method for measuring or estimating high-quality torsional receptances using two different methods based on the Receptance Decoupling Technique. In both methods, a T-block needs to be attached to facilitate the generation of torsion, and only the numerical receptance data of the T-block cast in a simple theoretical model and a few measured receptance data of the assembled system are required. Both methods are studied and assessed in numerical simulation, and the more robust method is further validated in experiments. The usage of rotational accelerometer is shown to significantly improve the quality of the estimation when the noise level is high. It is demonstrated that high-quality torsional receptances can be indirectly measured with high repeatability using the proposed method and thus can be used subsequently to identify torsional modal parameters, update finite element models, make structural modifications, or implement active torsional vibration control. Due to ubiquitous use of rotating machines, this novel method has significant applications.