刚度-质量-阻尼综合优化的船舶减振统一阻抗模型法

A unified impedance modelling method for ship structural dynamics synthetic layout optimization design

提出了船舶减振统一阻抗模型法,以结构阻抗值衡量减振能力,探讨同步进行刚度-阻振质量-阻尼材料综合配置的结构动力学布局优化设计。分别建立了基于结构原点阻抗、传递阻抗和阻抗级落差描述的三种动力学布局优化模型。以某军舰基座减振设计为例,验证所提出的统一阻抗模型法。算例中以基座各构件的厚度和大质量阻振方钢截面尺寸为尺寸设计变量,方钢和阻尼材料的布局为拓扑设计变量,利用模型映射变换方法,将该离散优化模型连续化。利用近似代理模型方法,求解该多频段动力学优化问题,验证刚度-阻振质量-阻尼材料同步优化设计的优越性。

Concurrent optimization of stiffness,blocking mass and damping materials have been challenges in structural dynamic design due to the difficulties in damping coefficient modifications in the dynamic analysis model caused by the topological change of damping materials.The layout of the blocking mass is optimized in the way of defining the design variables.The parameters are coordinated between the dynamic analysis model and the optimization design model.This paper discusses the simplified modeling methods and the unified structural dynamic analysis model considering the change of stiffness,blocking mass and damping material.Based on structural impedance,the vibration reduction capacity is measured,the unified impedance modelling method is established.Moreover,the model mapping transformation method is used to solve the problem of coordination between the dynamic analysis model and the optimization design model.Taking the vibration reduction design of a base in naval ship as an example,the proposed analysis model and optimization model method are verified.In the example,the optimization design is based on the thickness of the mounting panel,the size and layout of blocking mass and damping material as the topological design variables.The approximate surrogate model is applied to solve the optimization problem and the expected damping effect is achieved.