Objective Car body structure is the core load-bearing component of a high-speed EMU (Electric Multiple Unit). The rationality of its design directly affects various performance indicators of the train, such as operational safety, operational efficiency, and economy. Therefore, it is necessary to study the topology optimization design for the high-speed EMU car body structure.

Method Taking the aluminum alloy car body of high-speed EMU as an example, the design methods of topology optimization and parameter optimization are adopted. With the minimization of car body mass and maximization of the first-order ready-to-run mode as objectives, the strength meeting relevant standards as constraints, and the cross-sections of aluminum alloy profiles as variables, the topology design domain of the car body structure is reconstructed to obtain a car body cross-sectional structure with minimal material consumption and optimized structure. Simulation analysis methods are applied to conduct calculation and analysis on the strength, mode, and other properties of the optimized aluminum alloy car body structure, and the performance of the optimized car body structure is further verified through prototype trial production and bench tests.

Result & Conclusion The optimized car body fully meets the requirements of relevant standards such as TB/T 3451—2016 Strength Design and Test of Body Structures of EMU/DMU and TB/T 3548—2019 Strength Design and Test Accreditation Specification for Rolling Stock-General. The first-order ready-to-run modal frequencies are all greater than 10 Hz, and the weighted mass of the car body structure is approximately 9830 kg, which can meet the design objectives of a 10% weight reduction and the first-order ready-to-run modal frequencies greater than 10 Hz.