STUDI KARAKTERISTIK REDAMAN PELAT PLEXIGLAS PERSEGI PANJANG DENGAN GETARAN HARMONIK

• Main Author: SJAHMANTO, MOHAMAD
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/2155
• Institution: Institut Teknologi Bandung

Experiment on the rectangular plate plexiglas of 400x40x50 mm using clamp and supporting system for obtaining a damping ratio and a loss factor it was made. The system was vibrated by the excitation frequency from 20 to 180 Hz and measured from 3 different position with the dierent time. Measuring and data acquisition was applied recording method with computer program and manual method or direct reading front the Digital Multimeter. The method of calculation or analysis was used a logarithmic decrement, half power bandwidth and dynamic- magnification factor. Analysis result showed that with logarithmic decrement method, the damping ratio was decreasing from 10-13% to 4-6% and the maximum value appeared at a resonance. Calculated loss factor was obtained between 0.1 and 0.5 following the increasing frequency of excitation. When observation was made on the measuring point, it was obtained that the value of damping ratio for measuring point closed to the clamp was higher than the value of that for other measuring points. lath the based on half power bandwidth method and dynamic-magnification factor for the observation at a resonance range, the value of damping ratio was obtained about 25-40%, while analysis of loss factor was obtained about 0.5 up to 0.8. For observation with based on the measuring point, the value of damping ratio at the middle position was obtained higher then that was obtained at other positions.