Abstract: Composite materials are widely used in engineering structures for its excellent performances of high damping loss factor, low density, high special strength, high special stiffness etc. Design of composite structure is a combination process of the mechanical performance with the materials design. For quite a few design parameters and complex influencing factors in the process, the optimal design becomes very important. Based on the different vibration reduction evaluation criterions, various structural dynamic optimization design models can be formulated. And their effects for vibration reduction can be quite different. In this paper, a synthetic evaluation method, considering vibration level difference and power flow level difference with structure’s weight or power flow at the evaluation points as objective functions, is presented. Taking the structural dynamic optimization design of the steel-composite mounting as an example, the corresponding mathematical model is established. By introducing multi-island genetic method, the optimization problems are solved. Computational results show that using this model for composite structure optimization, more feasible solution than that using conventional optimization model can be obtained.

Key words: vibration and wave, hybrid steel - composite structure, dynamic optimization, power flow level difference, vibration level difference

摘要： 复合材料由于具有低密度、高阻尼和良好的比强度、比刚度等特性而被工程结构设计广泛采用。复合材料结构设计的特点在于力学性能设计和结构设计相结合，设计变量多，影响因素更为复杂，优化设计工作显得尤为重要。基于不同减振评价指标，结构动力学优化设计可以采用不同优化模型，减振效果也相差很大。以钢 -复合材料复合基座结构为例，研究采用功率流落差与振级落差进行减振效果评价，以结构总重量或评价点输出功率流等为目标函数，以钢板厚度、复合材料铺层数和铺层角度为设计变量，考虑应力约束时各种结构动力学优化数学模型，并采用多岛遗传算法进行求解，比较减振效果。研究表明，采用复合结构功率流优化模型能获得更佳减振效果。

关键词: 振动与波, 钢 - 复合材料复合结构, 动力学优化, 功率流落差, 振级落差