Noise, vibration, and harshness (NVH) are critical parameters influencing passenger comfort and overall satisfaction during bus travel. Despite some improvements, domestic bus manufacturers in Vietnam remain dependent on imported components, particularly in interior noise control and ride comfort. This study investigates the NVH characteristics of the Thaco Garden TB79S bus, with an emphasis on the role of the body structure in operational comfort. Numerical simulations were performed in MATLAB/Simulink and Hypermesh software under two representative road profiles common in Vietnam, a sine wave and a Class C random profile ISO 8608:2016 at 60 km/h. Results indicate that the maximum cabin sound pressure level (SPL) under sinusoidal excitation reached 192.04 dB, with resonances at 77 Hz and 99 Hz, while under random excitation the SPL varied between 80 and 138 dB. These SPL values should be regarded as relative references rather than actual levels perceived by occupants, since the model simplified other factors such as acoustic absorption, aerodynamic noise, tire noise, and engine noise. Meanwhile, ride comfort at the driver’s seat was evaluated according to ISO 2631- 1:1997/Amd 1:2010, with values of 0.112 and 0.813 m/s², clearly reflecting the influence of road surface irregularities on driver perception.

Noise, Vibration, Natural vibration, Harshness, NVH, FEM, Bus

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