Adaptive Optimization with Weld Fatigue Constraints Based on Surrogate Model for Railway Vehicles

• Autores: Gao Yuehua, Wenzhong Zhao
• Localización: Mechanics based design of structures and machines, ISSN 1539-7734, Vol. 42, Nº. 2, 2014, págs. 244-254
• Idioma: inglés
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• Resumen

  • As the speed of railway transportation grows rapidly, welded structures have been commonly used for the car bodies and bogies. Fatigue failure of a welded structure with fluctuating loads usually occurs at weld seams. And thus the fatigue strength of weld seams should be considered in the optimization of these structures. In this paper, an adaptive multidisciplinary optimization method is proposed for the lightweight optimization problem with weld fatigue constraints. The kriging surrogate models are used to replace the time-consuming computer simulations through the optimization procedure. The master S�Ncurve method in ASME standard is adopted for weld fatigue assessment due to its mesh-insensitivity and reliability. For a brake beam structure of a high-speed train, a lightweight optimization model with static strength and weld fatigue constraints is constructed and solved in light of the proposed optimization method. After optimization, the weight of the brake beam is reduced by 12.5% and the values of weld fatigue damage meet the requirements, which demonstrate the validity of the proposed optimization method. Furthermore, an optimization without weld fatigue constraints is implemented and the optimal design leads to unacceptable values of weld fatigue damage. This shows that the weld fatigue problems cannot be ignored in the optimization for welded structures.