Perpustakaan Digital ITB

The increasing demand of mass transportation indicates the need of development in public mass transportation in Indonesia, including the railway train sector. In a densely populated area or city, such as Jakarta, railway trains are one of the most cheap and effective option of transportation. A few developments on providing new railway trains or routes as well as technology enhancements have started to look steadily increasing. The challenge for engineers now is to evaluate and enhance railway performances regarding to the vibration and noise emission to keep passenger quality perception high. Although both vibration and sound can be understood separately, deep and thorough comprehension of the noise, vibration and harshness (NVH) phenomena as a correlation in this evaluation is required. This thesis presents the application of numerical analysis to assess NVH performance of railway structure triggered by structural dynamics. A finite element model of a railway single car body structure and some acoustic absorbers as add-ons are developed, with some simplifications made during modelling process. Input loads and boundary conditions are also defined. The calculations are performed then by ABAQUS software, by referring to three general methods of vibro-acoustic analysis; free vibration, frequency response, and acoustic pressure analysis. Acceleration results of the vibration analysis show dissimilar magnitudes, but similar trends to the experimental data, while acoustic pressure analysis shows an increasing value of sound pressure level (SPL) whenever the loads applied increases too. Observations on acoustic absorbers are also conducted, showing the result of SPL reduction on some range of frequency. Acknowledging how representative of numerical model is, the results shown signify the applicability of numerical method as an alternative tool to assess NVH performance level.