【作者】 陈晓利；

【导师】 盛美萍；

【作者基本信息】 西北工业大学 ， 环境工程， 2007， 硕士

【摘要】 本文研究受到国家自然科学基金与西北工业大学研究生种子创新基金资助。 导纳功率法结合了导纳和功率流的思想，能很好的反映结构内部振动能量的分布，以及结构之间的振动能量分配和功率流传输特性，但其计算尚需开展大量工作，离工程应用仍有一定距离，本文就针对导纳功率流法在结构振动与声辐射研究中的一些关键技术而展开探讨。 弹性圆柱壳体以及加筋圆柱壳体是船舶、水下航行器、航空飞行器、建筑结构等领域中广泛应用的结构形式，研究它的振动能量传输特性对研究复杂结构的振动及声辐射特性具有深远的意义。应用导纳功率流法可以得到圆柱壳体以及加筋圆柱壳体在外激励力作用下的任意振动特性。 如果没有进行声辐射的研究，那么关于结构声振特性的探讨是不完善的，因为在实际情况中，相对于结构振动的幅值以及振动能量的分布与传输来说，辐射到周围空间中声能量的大小同样是一个不能忽视的问题。本文详细探讨了板、壳结构在空气介质中的声辐射，得到了结构辐射效率的导纳表述式，相对于经典计算公式来说，改进后的公式大大提高了其在临界频率附近辐射效率的预测粘度。 应用导纳功率流法研究复杂结构的振动特性是发展导纳功率流理论的动力与目标，本文在复杂结构振动特性研究方面开展了有益的尝试。应用异纳功率流法研究了由两个半无限长圆柱壳组合而成的耦合圆柱壳体，以及由两个薄板垂直组合而成的L型板的振动特性，得到了在简谐力激励作用下，子结构在耦合处耦合作用的分布，以及结构上各点的振动响应。所获得的结论对于今后更复杂结构的振动研究具有指导意义。 综上所述，本文以一些典型结构以及复杂耦合结构为研究对象，解决了应用导纳功率流法对其进行结构振动与声辐射分析的关键技术。研究结果表明，该方法具有物理概念明确、应用灵活等特点，适用于工程计算，可以用于不同结构的振动特性以及声辐射的分析。更多还原

【Abstract】 The research was sponsored by Foundation of National Natural Science and Northwestern Polytechnical University Graduate Pioneering Seeded Foundation.Mobility power flow (MPF) method combines the concepts of mobility and power flow, it can reflect the vibration energy distribution inside of the structure directly, and can give the vibration energy and power flow transmission properties among substructures indirectly. However there still has a long way to the widely MPF method application, and a great deal of calculation works is needed. This thesis was completed in order to solve the key techniques in the process of structure sound & vibration investigation.Elastic and beam-stiffened cylindrical shells are common structures that applied in ship structures, torpedoes, as well as aviation and architecture establishments, it has great significance to study the vibration energy distribution and transmission properties for the future sound & vibration research of complex structures. By applying the MPF method, all the vibration characteristics of the cylindrical shell under external excitations were achieved in the thesis.Research of the structure sound & vibration is incomplete if there is no investigation about structure sound radiation. Because compared with structure vibration distribution and transmission, sound energy that radiated to the surround space also is a problem that can not be neglect in virtual project. Sound radiation of plate and shell structures in air medium was studied in this thesis, and the mobility-form expressed sound radiation efficiency was obtained. Compared with the classical calculation formulas, the reformed ones can improve the predicting precision greatly at frequencies near the critical frequency.To solve the complex coupled structure’s vibration characteristic is the motivity and object to develop the MPF method. In this thesis, attempts were done in applying the MPF method to solve complex coupled structure’s vibration characteristics. One attempt was for the coupled cylindrical shell which consists of two semi-infinite cylindrical shells, the other attempt was for the L-shape plate which is assembled by two thin plates perpendicularly. Coupling effect between the two substructures and the vibration response of each substructure were received under external point harmonic force excitations. All the conclusions are useful and have conducting significance for更多还原