EVALUATION AND TREATMENT OF NOISE IN LIGHT RAILWAY TRANSIT FLOOR BASED ON WAVEGUIDE FINITE ELEMENT - BOUNDARY ELEMENT METHOD

• Main Author: Khairin Nisa, Ainil
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/47770
• Institution: Institut Teknologi Bandung

Decreasing the noise level on the Light Railway Transit (LRT) is desirable to enhance acoustic comfort on the LRT. This study focuses on reducing the noise level of the LRT train floor. This decrease in noise level is marked by a reduction in sound power level, an increase in the value of transmission losses and an increase in the value of Sound Transmission Class (STC). The LRT train floor which has an extruded panel model structure is modeled using the Waveguide Finite Element - Boundary Element method. Simplification of the LRT train floor, double panel floor and simple double panel floor, is also modeled to determine the effect of each structure on the LRT train floor on the dispersion curve, mobility, sound power level, transmission loss value, and STC. to Variations of extruded panel tilt angle, density, damping loss factor, panel thickness, and thickness of the cavity on the LRT train floor is done to obtain alternative designs of LRT train floor that increase its transmission loss performance. Simulation results show that the STC value of the LRT train floor is 41 with a mass per length of 60 kg/m, with deficiencies at frequencies around 125 Hz, 500 Hz, 1000 Hz, and 3000 Hz. Increasing the thickness of the cavity can increase the STC value with a small increase in mass per length. Increasing panel thickness can increase the value of STC with a significant increase in mass per length. Increasing damping loss factor can increase the value of STC, but only increase the value of transmission loss in the frequency around modes. Increasing the density of the structure can increase the value of STC with a significant increase in mass per length. Increasing extruded panel tilt angle can increase the STC value with a very small decrease in mass per length. Alternative design taken is a train floor design with a cavity thickness of 9 cm, panel thickness of 5 mm, damping loss factor of 0,1, density of 3600 kg/m3, and the tilt angle of 55????. This design has an STC value of 47 with a mass per length of 87 kg/m.