CAJ | 학술논문

本文采用二次建模方法,对具有微观结构的粘弹性材料的声辐射问题进行了研究.第一次建模时针对包含单个内部结构的周期细胞进行精确的建模,根据有限元计算结果获得粘弹性阻尼层等效成正交各向异性材料的等效物性参数;第二次建模时,该粘弹性阻尼层可简单地用具有该等效物性参数的均匀材料替代.二次建模计算所划分网格的尺度较大,可选择的单元类型也更多.在作该材料的低频受激振动声辐射预报时,上述特点能够在保证计算精度的前提下,大幅度地降低计算成本,缩短计算时间.
본문채용이차건모방법,대구유미관결구적점탄성재료적성복사문제진행료연구.제일차건모시침대포함단개내부결구적주기세포진행정학적건모,근거유한원계산결과획득점탄성조니층등효성정교각향이성재료적등효물성삼수;제이차건모시,해점탄성조니층가간단지용구유해등효물성삼수적균균재료체대.이차건모계산소화분망격적척도교대,가선택적단원류형야경다.재작해재료적저빈수격진동성복사예보시,상술특점능구재보증계산정도적전제하,대폭도지강저계산성본,축단계산시간.
A twice modeling method in underwater sound radiation prediction for viscoelastic materials with inner voids under stimulation is developed.During the first modeling process, FEM method is adopted to get the strain and stress of elements in a single periodical cell, all these results can deduce the equivalent material properties of orthotropic material. Subsequently, the damping layers coated on the shell of the structure can be replaced by a homogeneous material with equivalent parameters. In the second modeling process, more various element types are chosen and larger element size is adopted.These merits may ensure a more precise sound radiation prediction level with less analysis time or cost in lower frequency band.