Operational Modal Analysis of an Axial Compressor Rotor and Casing System for the Online Identification of a Digital Twin

Abstract

Modal parameter identification can be a valuable tool in mechanical engineering to predict vibrational behaviour and avoid machine damage during operation. Operational modal analysis is an output-only identification tool motivated by the structural identification of civil engineering structures, which are excited by ambient conditions. This technique is increasingly applied in mechanical engineering in order to characterise the system behaviour during operation as modal parameters can vary under operating conditions. The following study investigates the application of operational modal analysis on an axial compressor under operating conditions. Since the modal parameters of the system change depending on the life history and during the operation of the system, a corresponding data analysis might allow us to identify the present status of the system. Eigenfrequencies and eigenvectors are studied for the use of structural health monitoring approaches. According to the analysis, eigenfrequencies represent robust parameters for the studied purpose. Eigenvectors are sensitive to damages but need further investigation, especially for rotating machinery. This study will help the user to set up a virtual model, which describes the system behaviour for different boundary conditions. This in turn, will provide an accurate prediction of the vibrational behaviour in order to assure a safe operation.

Vibration Signal Evaluation Based on K-Means Clustering as a Pre-Stage of Operational Modal Analysis for Structural Health Monitoring of Rotating Machines

“…In this context, machine learning techniques were used to solve challenges of automation, with emphasis on the works of [8,9], who used unsupervised learning to automatically interpret the results of the Stochastic Subspace Identification (SSI) technique. More recently, the matter has been addressed by [10][11][12][13][14][15][16][17][18], and existing approaches were already in use in [19,20] for condition monitoring of wind turbines, highlighting the relevance of the subject to current research.…”

Enhancing the Performance and Durability of Commercial Vehicle Cargo Box Frames through Modal Analysis

“…Furthermore, novel modal testing methods designed for structures rotating in water are assessed [12]. Additionally, the research focuses on the operational modal analysis of an axial compressor rotor and casing system, aiming to identify a digital twin online [13], as well as the modal analysis of lithium-ion batteries for electric vehicles [14]. Strain modal testing using fiber Bragg gratings is investigated specifically for automotive applications [15].…”