肋骨偏移误差对结构振动与声辐射的影响

Effect on Structural Vibration and Sound Radiation Due to Offset Errors of the Ribs

实际设计建造耐压壳体时,舱段结构的肋骨可能出现类似偏移这样的制造偏差。因此,研究肋骨制造偏差对水下结构振动与声辐射的影响变化规律,对于水下结构的声学分析具有重要的工程指导意义。以环肋圆柱壳为研究对象,采用结构有限元耦合流体边界元算法,研究了肋骨偏移程度、偏移肋骨的数量和偏移肋骨的位置对结构振动与声辐射的影响。数值计算结果表明:本研究所设计的工况中,肋骨偏移程度、偏移肋骨的数量和偏移肋骨的位置对环肋圆柱壳声辐射功率级的影响可以忽略;肋骨偏移程度对环肋圆柱壳的高频均方法向速度级有较大的影响,但当肋骨偏移距离较小时,肋骨偏移位置和数量的变化对结构的均方法向速度级影响很小。结论对于水下结构声学分析具有一定的参考价值。

Offset errors of ribs maybe appear on the construction process of a submarine. Therefore, the investigation of the influence of the offset errors of the ribs on vibration and acoustic radiation of the subma- rine is of great significance for structural acoustic analysis. In this paper, a structural finite element cou- pled with fluid boundary element method （FEM-BEM） is adopted to investigate the effect on the vibration and acoustic radiation of a ring stiffened cylinder due to the offset error of the ribs. Numerical calculation points out that the offset distance, placement and number of the ribs affect less on the radiated sound power level of the ring stiffened cylinder. Furthermore, when the offset distance is relatively small, the placement and number of the ribs have small effects on the mean-square normal velocity level of the ring stiffened cyl- inder. The conclusion is a valuable reference of radiated noise analysis of submarines.