THE EXPERIMENTAL STUDY OF THE VIBRATION PHENOMENON DUE TO RUBBING ON ROTOR SYSTEM

• Main Author: Paembonan, Grymen
• Format: Theses
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/55690
• Institution: Institut Teknologi Bandung

Rubbing on rotating machinery equipment is an avoided problem because its results seriuous damage. Rubbing is caused by the existence of the undesirable contact between rotating and stationary component with minimum size of gap. Contact on the machine can occur intermittently or continuously. The experimental research aims to determine the vibration response of rubbing and reveals the differences in characteristics between intermittent contact and continuous contact. The rubbing phenomenon is excited by a threaded brass pin that contacts a shaft. The experiment of rubbing varied in 3 conditions: without rubbing, intermittent rubbing, and continuous rubbing. Every condition is tested based on vibration and dwell-time parameters. The vibration signal is a waveform gathered from a proximity sensor, accelerometer, and keyphasor, while the dwell-time is gathered from 9 volts DC voltage connected to the contact detector. All of the signals are acquired by NI-DAQ 6008 instrument and processed by Matlab software. The experiment results from the proximity sensor revealed lower levels of vibration in intermittent and continuous rubbing than without rubbing condition. However, the lower level of vibration is also followed by the shifted position of balance resonance and phase as a result of the changing of stiffness. Vibration from the accelerometer showed a strong response in intermitten rubbing as the tremendous increase of vibration level due to the impact, while on the continuous rubbing shows changing of the vibration level is proportional to the rise of rotational speed. The experiment also revealed the characteristics of the intermittent contact which is marked by the short dwell-time that is under 14 percent, vibration level increase drastically along with impact, and the pre-dominant frequencies contents iv harmonics of 1xRPM frequency. In contrast when compared to the continuous contact which is marked with almost 100 percent dwell-time, slowly increase of vibration level and the pre-dominant frequencies contents on random frequency.