面向高速列车车体可靠性的复杂结构安定域内双尺度优化研究

The body of a high-speed train is a typical, complicated mechanical structure, and its reliability analysis, design ideas and technologies application are important links for the safety of a high-speed transportation system. The research object is the reliability design and application of the body structure of a high speed train which should satisfy with many restrictions including the manufacturing technologies, material and connections under considering completely real working conditions. A multi-scale numerical simulation analysis and optimization design based on "global-, local-, and meso-structure" of the body structure is presented, to research deeply and describe the single action mechanism of main operation loads on the high-speed train based on the global analysis, analyze the contribution and influence of loads under coupled loading conditions, and establish the relations among the real loads, design loads and design parameters, optimize the structure arrangement by combining an optimization method of the structure dynamical character. Main design factors are extracted from the analysis of many real structure failures, and the recovery analysis on load-carrying capability of local structures based on the bucket brigade sub-models is achieved for dynamic response optimization design. Combining the universality improvement of the limit/shakedown theory and formulas, the safety margin of local structures is evaluated from the analysis of meso-structures. On the design theory and method, necessary theories and engineering methods will be provided for an effective, scientific industry design standard and higher structure safety level which combined traditional design principles and advanced numerical analysis will be explored, and an available method of the structural test and safety evaluation will be established.

高速列车车体为典型的复杂机械结构，其可靠性设计理念与应用是高速运输系统安全的重要环节。在运行工况特殊性、制造工艺、材料性能、连接方式等约束下，以高速列车车体结构的可靠性设计为研究对象，提出复杂结构"整体－局部－细观"双尺度仿真分析与优化设计方法，整体分析阐述运行载荷对结构的作用机理，解析多载荷耦合的影响规律及各自贡献度，建立实际载荷、设计载荷与设计参数之间的关系，结合结构动力特性优化方法研究结构布局优化及安全裕度分配；从实际结构破坏现象分析提炼主要影响因素，实现以传递式子模型为基础的局部结构复原性分析，建立局部结构动力响应优化设计方法；结合极限/安定性理论与计算的普适性改进，以细观分析完善局部结构安全评估。在设计理论与方法上，探索设计原则、数值分析理论、优化算法相结合，建立面向结构可靠性的优化设计、评估方法，为形成有效、科学的行业设计原则及提升结构可靠性水平提供理论支撑和工程方法。

高速列车车体作为典型的复杂机械结构，运行工况载荷复杂且受制造工艺、连接方式等因素的影响，其可靠性设计与应用是高速运输系统安全的重要环节。项目研究在以下方面取得创新性成果：（1）基于高速列车外流场仿真的气动载荷研究，提出面向大型结构单向流固耦合不匹配网格数据传递问题的新型插值算法，有效处理了高速列车流场计算域结果向固体域的转换，误差控制优于通用软件插值结果。不同维度气动载荷规律及应用研究结论为结构分析的基础；（2）基于耦合载荷的结构双尺度分析，建立用于车辆动力学的耦合输入条件，提出时域异步载荷的耦合方法，由时序匹配实现机械与流体载荷的耦合,研究单一、耦合载荷对结构承载的作用机理，阐述了实际载荷与设计载荷的关系；提出复杂结构由“整体-局部”的双尺度分析方法，切割边界域面插值方法解决车体局部结构多级传递子模型的边界条件“真实”传递；（3）结构“细观”分析的极限/安定高效数值方法研究，基于经典的极限/安定计算列式，以控制数学规划求解变量缩减数值计算规模，同时，建立以改进应变强化模型和N维载荷空间下的静力安定计算列式，是为细观结构微塑形条件下优化设计与可靠性评估的算法基础。