关键词: 结构优化设计, 钻机底座, 数学模型, 应力约束, 箱式底座, 目标函数, 序列二次规划法, 位移约束, 曲线拟合, 杆系

Abstract: The optimum structual design of a drilling rig foundation made up of bars was studied with sequential quadratic programming for specified structual topology and geometry.A mathematical model was given with its objective of minimizing the structual mass and constraints of local buckling in addition to the usual stress,member size and displacement constraints.The relationship between various parameters of element sections was obtained by curve fitting.Stress constraints were converted into quasi-size constrains to simplify the mathematical model.The sequential quadratic programming was utilized to avoid the complex calculation in sensitivity analysis.An algorithm in incremental form was given under Kuhn-Tucker condition.In order to test the theory and computer program developed,an actual drilling foundation with 176 nodes and 265 elements was calculated in contrast with its original design.The calculation converged after eight iterations and the structual mass was reduced by 12.6 percent.