Paper Title
Design Analysis of the Primary Suspension’s Outer Spring of Fiat Bogie

Abstract
This study delves into the design analysis of the outer spring of the primary suspension within the FIAT Bogie system for AC tier 3 coaches. This study investigates the impact of transverse forces on helical compression springs in railway vehicle suspensions, focusing on the FIAT bogie primary suspensions. Finite element analysis (FEA) was used for static and dynamic simulations to assess the transverse force effects on spring performance. The harmonic analysis identifies resonance at approximately 75 Hz, reflecting the operational conditions. A dynamic model combines track dynamics with a flexible coil spring model to understand the vibrations. The results show that the stress exceeds the material limits at resonance, highlighting the importance of considering transverse forces in the models. The transverse stiffness variations in springs emphasize the need for accurate stress evaluation. The dynamic analysis revealed that the stress exceeded the material strength, indicating potential failure. The study suggests a factor of safety of less than one, projecting spring failure between 10 and 106cycles under varying loads. Refining models to include transverse forces is crucial for precise simulations in engineering applications to enhance the design reliability of railway suspensions for improved safety and performance. Keywords - Transverse Force, Finite Element Analysis, Harmonic Analysis, Track Dynamics, Resonance, Transverse Stiffness, Dynamic Analysis