Dynamic Response of Linke Hofmann Busch (LHB) Rail Coach Considering Suspended Equipments

Abstract

Objectives: The study of rail coach under dynamic condition has been ever needed for rail engineers. Vertical and lateral responses of coach body are the primary parameters to assess the comfort level of travelling passengers. Methods: The present study aims at dynamic behavior of a LHB coach against track irregularities and the suspended equipments underneath the coach body. The suspended equipments are mounted to provide basic amenity requirements. The track irregularities are assumed to be random profile and characterized in terms of PSD as per FRA standard. The coach body is modeled using finite element methodology in which system matrices such as mass, stiffness and damping matrices are obtained for Eigen value solution. Findings: Using the modal parameters obtained as above and PSD of track irregularities, both vertical and lateral Mean Square Acceleration Responses (MSAR) are determined at various points of interest on coach body. It is observed that the peak responses in vertical direction occur in low frequency range (0-10 Hz) which is caused by long wavelength irregularities of track that causes discomfort. It is also observed that peak lateral responses occur at still lower frequency as compared to vertical response which is again discomfort to vehicle riders. This is because of the sensitivity of human being against vibratory motion falls in low frequency range. This concludes that there is a scope of improvement in comfort level with minor adjustments of suspended equipments of coach body. The present paper deals with dynamic analysis of coach body considering suspended equipments which have not been addressed earlier. Also, it is suggested that if the mass and relative position of suspended equipments including other parameters are changed, then the ride comfort can be improved. Application: The outcome of the paper may helps the rail coach designer to improve the future coach design providing better comfort even in the low frequency range of operation. Keywords: LHB Coach, PSD, Responses, Suspended Equipments