船艉结构静动态多目标优化设计

Multi-objective optimization of ship stern under static and seismic loading

建立用于船体结构静动力学性能一体化设计优化的2种多目标优化模型:基于多目标遗传算法的多目标优化模型和基于多学科优化技术的多目标协同优化模型。模型均使用矩阵描述由板材厚度和骨材型号构成的离散设计变量集,以结构质量最小化和最大加速度最小化组成多目标函数。以某集装箱船艉部结构为例,对其进行了结构静力学、动力特性和动力响应的计算分析与优化设计。优化后的结构不仅具有更轻的质量、更低的振动水平,而且具有更高的固有频率储备,同时仍满足强度和刚度要求。

The goal of this effort was to develop and compare two different multi-objective optimization models for the design of ship stern.They include the multi-objective optimization model based on the fast non-dominated sorting genetic algorithm and the multi-objective collaborative optimization model based on the multidisciplinary analysis.The discrete design variable sets including the thickness of plate and the model number of beam are depicted with matrix.The objective functions are how to get the minimum structural mass in the static analysis and how to minimize the maximum acceleration of structure in the dynamic analysis.The proposed models were demonstrated with an optimization problem of container ship stern under static and seismic loading.The obtained optimal design indicates the great potential of decreasing structural mass and vibration level and increasing natural frequency reserve under the strength and stiffness requirements.The analysis progress and results show that the models are feasible and well-suited for using in actual optimization problems of ship design.