加肋有限圆柱壳体的边界条件对其振动和声辐射的影响

Effect on acoustic radiation of ribbed cylindrical shell due to boundary conditions

采用结构有限元耦合流体边界元的附加质量附加阻尼算法,建立了加肋有限圆柱壳体的有限元模型,并采用该模型对十四种方案的水下振动和声辐射进行了分析,讨论了模型边界条件对其水下振动和声辐射的影响规律以及在采用舱段模型代替整艇模型进行噪声估算时中间舱段长度的选取原则。结果表明用一个舱段模拟整艇的动态特性容易造成低频整体模态振型的缺失,在舱段首阶弯曲振动的模态频率以上,采用舱段来预报整艇的表面振动和辐射声功率是可以接受的;当整艇艇长不超过中间舱段长度的两倍时,可以采用舱段模型代替整艇模型进行噪声估算。

An additional mass and damping approach combining Finite Element Method （FEM） with Boundary Element Method （BEM） is proposed to calculate underwater vibration and acoustic radiation from a ring stiffened cylindrical shell with different boundary conditions. The comparison and analysis of the results show that using a cabin model of submarine replacing a full-scale model for vibration and noise estimation would stride over the low modes. When the frequency is exceeding the cabin＇s first bending model frequency or the full length is less than twice of the cabin＇ s, using a cabin model replacing a full-scale model for vibration and noise estimation is feasible.