ERROR ANALYSIS OF FRF MAGNITUDE DUE TO SWEPT RATE VARIATION

• Main Author: HADY (NIM:131 06 157); Pembimbing: Dr. Ir. Zainal Abidin, LUTHFI
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/16321
• Institution: Institut Teknologi Bandung

FRF measurement for industrial structures is generally done by using burst random signal because this signal has wide frequency contents and it can be performed quickly. <br /> <br /> <br /> However, this type of measurement is very susceptible to errors due to noise because the excitation level cannot be controlled. Recently, FRF measurement has been developed <br /> <br /> <br /> using swept sine signal. This method has one important parameter, that is the swept rate. Inappropriate swept rate selection can cause error of the FRF magnitude. Therefore, this research is dedicated to analyze the error of FRF magnitude due to swept rate variation. <br /> <br /> <br /> This research is divided into two main parts; there are simulation section using MATLAB and experimental section. The simulation section begins with calculation of the theoretical of FRF magnitude. The research is then followed by some simulations of FRF calculation using swept sine with various swept rate. The FRF magnitudes obtained from these simulations are compared with the theoretical value and then analyzed to know the effect of swept rate variation on the FRF magnitude error. Finally, some experiments are performed to check the simulation results for a single degree of freedom system. <br /> <br /> <br /> Based on these simulation and experiment results, it can be concluded that inappropriate swept rate selection can cause significant errors of FRF magnitude. Measurement using <br /> <br /> <br /> low swept rate gives better results than measurement with higher swept rate. Therefore, the accuracy of FRF magnitude can be improved by reducing the swept rate value.