基于相似理论对水下复杂壳体的振动和声辐射预报

PREDICTION OF VIBRATION RESPONSE AND SOUND RADIATION OF THE UNDERWATER COMPLEX SHELL BY USING SIMILITUDE PRINCIPLE

采用有限元和球函数相结合的方法,建立水下复杂壳体———两端带半球壳的加肋弹性圆柱壳的振动、耦合振动和声辐射方程,运用方程分析法,导出水下复杂壳体的振动、耦合振动和声辐射的相似关系,根据建立的相似关系实现对壳体的振动响应和声辐射的预报。采用大型有限元软件ANSYS对具有相似关系的模型和原型的振动响应和声场进行分析,算例表明,方法切实可行并且为预报水下大型复杂结构体的振动响应和耦合声场提供了一种简洁、实用的研究方法。

The equations of vibration, coupled vibration and sound radiation of the ring-stiffened cylindrical shell with hemispherical cap at the end are derived by using FEM combined with spherical function extension method. By using the similitude principle the similitude conditions and concerned relationships of the submerged complex shell are derived, according to which, the vibration response and sound radiation of the submerged big-scaled and complex shell can be accurately predicted with a small similitude model. The similitude relations of vibration response and sound radiation between prototype and model are analyzed by the finite element software ANSYS. Numerical results are given for verification.