层合板频率响应与声功率双目标优化设计

利用遗传算法对复合材料层合板结构的固有频率间隔和辐射声功率进行双目标优化设计。利用分层理论结合有限元模型求解层合板的固有频率和振速分布。通过声辐射模态理论,计算层合板结构辐射声功率。以铺设角度作为设计变量,第一阶与第二阶固有频率间隔和辐射声功率作为双目标优化目标函数,以某4层的层合板结构为例,采用目标加权法优化目标函数。研究了不同权重系数、不同频率时固有频率间隔最大化和声功率最小化对应的优化铺设角度。由数值分析结果可知:不同的权重系数比下获得的Pareto最优解不同;在同一权重系数下,两个优化目标所起的作用不尽相同;随着频率的增加,选择相对较大的权重系数可使Pareto最优解较好地兼顾两个优化目标。

Double objective optimization of frequency response and acoustic power for laminated composite plates

Both the separation between two adjacent natural frequencies and the sound power of laminated composite plate are optimized by use of genetic algorithm in this paper. The layer-wise finite element model is imposed to determine the natural frequencies and the velocity distributions of laminated composite plates. Based on the acoustic radiation model, sound power is calculated. The fiber laying angles are chosen as design variables and the design objective is to minimize the sound power and to maximize the separation of two adjacent natural frequencies. A four-layer laminated plate are used as examples, the objective weighting method is used to optimize the objective function. And the optimal laying angles with sound power minimization and frequency separation maximization are discussed under different frequencies and different weight coefficients. The numerical simulations show that there are different Pareto optimal solutions under different weight coefficients. With frequency increasing, a relatively large weighting coefficient can be chosen for the Pareto optimal solution to balance the two optimization objectives.