Spectrum Analysis of Linear Time Invariant Gyroscopic System

• Main Author: Ishak, Siti Nadiah
• Format: Final Year Project
• Language: English
• Published: Universiti Teknologi PETRONAS 2011
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://utpedia.utp.edu.my/10110/1/2011%20Bachelor%20-%20Spectrum%20Analysis%20Of%20Lenear%20Time%20Invariant%20Gyroscopic%20System.pdf; http://utpedia.utp.edu.my/10110/

This dissertation presents the research that had been done on Final Year Project (FYP) entitled Spectrum Analysis of Linear Time Invariant Gyroscopic System. This project involved dynamic analysis of a system called gyroscopic system using computer software which is ANSYS. This project is an extension of previous project done by Sibi Chacko on determination of response spectrum of gyroscopic system when subjected to random excitation by using finite element method. This project is focused on research and study on random vibration analysis of a compliant shaft about using ANSYS Spectrum Analysis. The first part of this study covered on the research and study of previous gyroscopic system and application of finite element method for random vibration analysis using ANSYS software. The shaft is modeled into beam element and free to rotate about it axis to indicates the gyroscopic effect on the beam element. The second part of this study is done by conducting the analysis on the beam element using ANSYS. The analysis is done in two parts which is free vibration analysis and random vibration analysis. Free vibration or ANSYS Modal Analysis is done prior to calculate the response spectrum in ANSYS Spectrum Analysis. Results obtained in ANSYS Modal Analysis are in form of mode shapes and natural frequencies when the beam undergoes transverse vibration. ANSYS Spectrum Analysis is carried out for random vibration analysis. The beam element is subjected to white noise excitation at both ends and analysis is carried out. White noise PSD input of value 1 is used as input excitation at beam element ends. Power Spectral Density (PSD) response is the results of interest for random vibration analysis. The graph obtained is plotted in power spectral density function in frequency domain. The response spectrum is extracted at any nodes and characteristics of the response are analyzed. The PSD versus frequency graph are plotted at different node to analyze the trend of the response. PSD response graph for each node are compared and frequency at where the PSD excited is calculated. v