基于多岛遗传算法的深海复合材料悬链线立管优化设计

摘要

In deepwater resource exploitation, fiber reinforced composite materials offer several advantages, such as high specific strength, high corrosion resistance, and high fatigue resistance. However, application of composites to offshore risers also introduces a large number of design variables and constraints in structural design due to the ani⁃sotropy of composite materials and multi⁃layer structures. A methodology was presented for optimization design of composite catenary risers based on the global⁃local analysis, with the consideration of design and safety require⁃ments. First, the classical lamination theory was used to obtain the equivalent mechanical properties of the laminat⁃ed tube, and next an equivalent structural model was built and a global dynamic analysis of it under the load of o⁃cean environment was performed. Finally, the optimization procedure was applied by taking the thickness and wind⁃ing angle of layers as design variables and the strength and buckling load of different dangerous cross sections as constraints under various working conditions. The multi⁃island genetic algorithm was used as the optimal strategy;the optimized composite catenary riser meets the strength and stiffness design requirements and saves a certain a⁃mount of composite materials. Research shows that the proposed methodology of composite catenary riser optimiza⁃tion design based on multi⁃island genetic algorithm is feasible.%　　由于复合材料具有高比强度、耐腐蚀以及疲劳性能好，适用于深海开发，但其各向异性及多层铺设的结构设计引入大量设计变量和约束，针对深海复合材料悬链线立管建立了整体分析与局部优化相结合的优化设计模型，在设计需求及安全性的条件下进行优化设计。首先根据经典层合理论得到层合管的等效力学属性，然后建立等效结构模型并对其进行海洋环境载荷下的整体动力分析，最后以复合材料管体铺层厚度和纤维铺角为设计变量，以多工况下不同危险截面的强度和屈曲条件作为约束，使用多岛遗传算法进行优化设计。优化后的复合材料悬链线立管接头满足强度与刚度设计要求，并节省一定的复合材料用量。所提出的复合材料悬链线立管多岛遗传算法的优化设计具有可行性。