考虑模态因素的齿轨动车车体地板梁的结构拓扑优化

STRUCTURAL TOPOLOGY OPTIMIZATION FOR FLOOR BEAM OF RACK EMU BODY CONSIDERING MODAL FACTORS

齿轨动车车体的轻量化是实现齿轨动车具有较强爬坡能力和舒适性等特性的关键因素之一。针对齿轨动车车体地板粱的轻量化设计,提出了一种基于模态分析、拓扑优化理论的二维与三维相结合的结构设计方法。首先,利用有限元法和结构优化设计软件对车体地板梁的二维截面进行了以应变能最小化的拓扑优化,获取了粗截面拓扑构型。然后,基于粗拓扑构型,以车体地板粱的三维结构为对象进行应变能最小化和模态最大化的多目标拓扑优化,得到了包含模态因素的地板粱的三维结构形状。最后,基于得到的两种优化结果与地板粱的可制造性,构造了一种适用于齿轨地板粱截面的新构型,并对其进行了与原结构相同边界条件下的有限元仿真对比分析和验证。结果显示该构型结构的强度、刚度及模态性能满足齿轨动车车体的要求,并且优化结构的质量较原结构下降了6.835%。

The lightweight of rack EMU(Electric Multiple Units)body is one of the key factors to realize the strong climbing ability and comfort of rack EMU.Aiming at the lightweight design of rack EMU body floor beam,a structural design method combining 2 D with 3 D based on modal analysis and topology optimization theory was proposed.Firstly,the topology optimization of the 2 D section of floor beam with the minimum strain energy was carried out by using the finite element analysis and the structural optimization design software,and the topology configuration of the coarse section was obtained.Then,based on the coarse topological configuration,the multi-objective topology optimization of strain energy minimization and modal maximization for the 3 D structure of floor beam were carried out to obtain the 3 D structure shape of floor beam containing modal factors.Finally,the new configuration suitable for the rack-rail floor beam section was constructed based on the two optimization results and the manufacturability of floor beam,and the finite element simulation results were compared,analyzed and verified under the same boundary conditions as the original structure.The results show that the strength,stiffness and modal performance of the configuration satisfy with the requirements of the rack EMU body,and the quality of the optimized structure is 6.835%lower than the original structure.