Design and analysis of lightweight freight wagon structures according to the standard of the State Railway of Thailand

This study is focused on the design of a novel lightweight freight wagon and the subsequent structural analysis in accordance with the State Railway of Thailand's freight wagon standards. Three-dimensional representations of three underframe wagon structures were generated using computer-aided design software. The primary objective is to create a lighter-weight freight wagon that adheres to the State Railway of Thailand's acceptable standards. These 3-D models of freight wagons are designed based on the actual dimensions of real wagons capable to carry two of 20-foot-long containers. The variations in the designed wagon models primarily involve the connection patterns of structural members and the minimization of material usage. Following the creation of these 3-D models, a computer simulation employing the finite element method is conducted to assess the structural strength of the wagons. The original wagon model is validated by comparing it with a real, in-service wagon in terms of damage points and deformations. Subsequent models are then developed based on simulation results, aiming to meet the reference standards. As a result, the final freight wagon model achieves a 15.11% reduction in weight compared to the original model, while maintaining a safety factor for the entire wagon structure that exceeds the 1.3 threshold set by the State Railway of Thailand.