基于有限元分析的自升式平台桁架腿选型优化设计

桁架腿作为自升式平台最为常见的桩腿结构型式，其拓扑型式、结构形状和构件尺寸设计对平台结构响应有重要影响。针对这一问题．笔者将有限元分析和数值优化方法有机结合，建立了复杂环境下桁架腿结构的多约束条件的优化模型，应用ANSYS优化模块进行求解。优化过程中，针对两层设计变量耦合困难的问题，分层优化方法。为验证优化模型和方法的可靠性，对某自升式平台桁架腿进行了选型优化设计。优化结果表明，本文采用的优化模型和方法简单实用，优化效果显著，为自升式平台桁架腿的概念设计提供了一种有效工具。

Optimum Lectotype of Jack-up Truss-type Leg based on FEA

Analysis of existing jack-up units indicated that truss-type leg＇s stiffness and intensity had a close relationship with topology pattern, configuration dimensions and cross section dimensions of the components. The theoretical and numerical methods of structural optimization for truss-type leg under the action of multi-loads were studied in this thesis. An optimization model of truss-type leg with multiple constraints was established and solved via ANSYS. The optimization process was divided into two levels to solve the coupling problem of two kinds of variables. To validate the feasibility of the optimization, an example was performed. The results indicated that models and methods of optimum lectotype in this thesis were effective and could be used in the concept design of the trusstype leg.