Finite element simulation of the railway coach shell assembly process

Thin sheets covering the skeleton of the railway coach shell undergo severe deformations during the manufacturing process. A comprehensive three-dimensional finite element model has been developed to simulate the manufacture of the complete coach shell assembly. The analysis has been extended by varying the camber, the self-weight of the coach shell and the thickness of the side panel sheet, to identify the exact cause for the coach shell deformation. Camber, a positive deflection given intentionally to compensate for the sagging of the coach, is one of the very important design parameters in the manufacture of railway coaches. A three-step analysis is suggested to calculate the correct camber. It has been demonstrated that the camber value arrived at by the conventional method is not accurate and a correction factor is required. The welding of the side panel to the underframe is a crucial determinant of camber. This issue is addressed through a comprehensive finite element analysis.