Lightweight design of materials for rubber-tired trains

Abstract

This study proposes a performance-driven material substitution lightweight technology for the head car (MC1) of an electronically guided rubber-tired train, in response to the development of urban rail transit and energy-saving and environmental protection policies. A finite element model of the MC1 vehicle was established to conduct modal and static strength analyses. The modal analysis revealed the first-order torsional and bending vibration modes, reflecting the overall stiffness performance of the vehicle. Sensitivity analysis under horizontal bending and extreme bending-torsion conditions identified key components significantly affecting stiffness and static strength. Based on the theories of equivalent stiffness and strength, a material substitution scheme was developed and applied to achieve the lightweight design of the MC1 vehicle. After optimization, the total mass of the vehicle was reduced to 10.44 tons, achieving a weight reduction of 8.02 %, with overall stiffness and static strength meeting the design requirements.Furthermore, a fatigue life analysis was performed on the optimized carbody structure. Results showed that the fatigue-critical region was concentrated in the driver’s cab floor area, and the structural load path remained stable. Considering actual operating conditions, the fatigue limit mileage of the optimized structure is approximately 2.0339 million kilometers, corresponding to a fatigue service life of about 27.1 years. Although this is slightly lower than the pre-optimization value, it still significantly exceeds the designed service life and satisfies the engineering durability requirements. This study further confirms that the proposed lightweighting scheme effectively achieves weight reduction while ensuring structural performance and fatigue reliability, demonstrating strong engineering applicability.

Keywords

• Rubber-tired train
• Lightweighting
• Sensitivity analysis
• Modal
• Static strength