面向高筋筒壳的结构优化设计和承载规律研究

Research on structural optimization design and load-carrying law for cylindrical shell with high ribs

为探究轴压下高筋筒壳结构承载潜力与构型参数分布规律,利用实验设计技术及代理模型加点优化方法,面向多种加筋构型开展了构型参数优化,并基于K-means聚类方法和斯皮尔曼相关性分析对具有高承载效率特征的结构构型参数分布规律开展了探究。结果表明,相比于低筋筒壳及蒙皮桁条筒壳结构,高筋筒壳结构的承载效率具有显著优势,对于正置正交加筋构型,提升幅度约为16.990%~54.741%;高筋筒壳结构的主要失效模式为强度主导的局部弹塑性屈曲,其承载主体为纵向筋条,蒙皮次之,而环向筋条对结构承载贡献较小,且增加纵向筋条数量对承载效率提升的作用最为显著。因此,为提升结构承载效率,高筋筒壳结构设计特征建议为“疏环筋、密纵筋”,筒壳半径与筋条高度的比值建议为55.8~133.0之间,筋条高度与蒙皮厚度的比值主要在2.3~4.0之间。相关研究可为下一代运载火箭主体结构选型及设计提供参考。

In order to discuss the load-carrying potential and configuration parameter distribution law of cylindrical shell with high ribs under axial compression,configuration parameters were optimized for various stiffened cylinders using experimental design technology and surrogate-based optimization method.Based on K-means clustering method and Spearman correlation analysis the distribution law of structural configuration parameters with high load-carrying efficiency was explored.The results show that compared with the cylindrical shell with low ribs and the skinned truss structure,the load-carrying efficiency of the cylindrical shell with high ribs has significant advantages,and the improvement range for the orthogonally stiffened configuration is about 16.990%~54.741%;the main failure mode of optimized cylindrical shell with high ribs is the strength-dominated local elastic-plastic buckling;the main load-carrying component of the structure is the longitudinal ribs,followed by the skin,while the circumferential ribs have little contribution to the load-carrying ability of the structure;increasing the number of longitudinal ribs has the most significant effect on the improvement of load-carrying efficiency.Therefore,in order to improve the load-carrying efficiency of the structure,the design features of the cylindrical shell with high ribs are suggested to be“sparse circumferential ribs and dense longitudinal ribs”,the ratio of the shell radius to the rib height is suggested to be 55.8 to 133.0,and the ratio of the rib height to the skin thickness is predominantly 2.3 to 4.0.Relevant research can provide a reference for the selection and design of the main structure of the next-generation launch vehicle.