IMPROVING THE SOUND ABSORPTION PERFORMANCE OF OIL PALM EMPTY FRUIT-BASED (OPEFB) COMPOSITE PANEL USING RIGID INCLUSION
Sound absorbers have become one of the most crucial elements in noise control. With the known hazards of mineral fibers and sustainability aspects, natural fiber materials have been extensively developed as sound absorbers, such as pineapple leaf fiber, kenaf plant fiber, and oil palm empty fruit. C...
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| Format: | Final Project |
| Language: | Indonesia |
| Online Access: | https://digilib.itb.ac.id/gdl/view/83722 |
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| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | Sound absorbers have become one of the most crucial elements in noise control. With the known hazards of mineral fibers and sustainability aspects, natural fiber materials have been extensively developed as sound absorbers, such as pineapple leaf fiber, kenaf plant fiber, and oil palm empty fruit. Considering that Indonesia is one of the world's largest palm oil producers, the equivalent waste can be used to create sustainable sound-absorbing materials. Generally, fiber-based sound absorbers still exhibit unsatisfactory performance, particularly before 2708 Hz and after where absorption coefficients are lacking and are not evenly distributed respectively. To enhance the insufficient absorption coefficient values, several methods can be applied, such as thickening the panel or using resonators like Helmholtz resonators. However, there has been another development that can improve the performance of a sound absorber without thickening it, namely by using rigid inclusion.
In this study, rigid inclusion was combined with an oil palm empty fruit-based (OPEFB) sound-absorbing composite to improve the absorption performance of the sound absorber within a certain frequency range. Numerical modeling and simulation of sound absorption were conducted on the sound-absorbing composite after being combined with rigid inclusion, with variations in the shape and position within the sound-absorbing composite. The simulation results indicate that it is not the shape that determines the frequency range enhanced by the rigid inclusion but rather the configuration of the position, width, and length of the rigid inclusion that determines the frequency range to be improved. The shorter a rigid inclusion, when placed in the center, will not enhance the absorption performance of the sound absorber. However, when placed closer to the composite surface or the rigid wall boundary, even a small-sized rigid inclusion can have an impact. When compared based on placement, without changing dimensions, the lower frequency range's absorption performance will be improved when the rigid inclusion is positioned closer to the composite surface. Conversely, when positioned closer to the rigid wall boundary, absorption performance will increase in the higher frequency range. Experimental validation results show trends similar to the simulation results.
Keywords: sound absorption, modelling, simulation, finite-element method, oil palm empty fruit-based, composite, rigid inclusion?
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