摘要
本文采用复合材料结构有限元和可压缩流体边界元耦合分析方法 ,研究了重流体介质(HeavyFluid)中含层间分层损伤复合材料层合板结构的声特征值问题。在建立分析模型时 ,对完整与受损层合板结构采用有限元方法离散 ;而针对水中结构声辐射的特点 ,对可压缩流体介质中声压力场进行边界元离散 ,在此基础上讨论了含层间分层损伤复合材料层合结构的动力声特征值问题。文中给出的典型算例结果与参考文献结果吻合较好。同时以内含层间椭圆型分层损伤的复合材料层合板为典型结构 ,在重流体介质中探讨了影响结构声特征值的因素 ,本文工作为评判含层间损伤对其动力特征值的影响提供了一种有效的计算方法 。
Using boundary element - finite element coupling analysis method, an acoustic eigen - analysis problem of damaged composite laminated structure in heavy fluid is investigated. A finite element formula is established on basis of Mindlin laminated plate theory and the special selecting numerical integration scheme. A delamination constrain model of the damaged laminated structure is built up and a virtual interface element is developed to prevent the overlap and penetration between the upper and lower sublaminates at the delamination region. For a heavy fluid load condition, because the vibration of the elastic structures is strongly coupled with the wave motion in an acoustic medium, and the eigen - frequency of the structure are identified by maximum of the acoustic power radiated from the structure. The interaction between an acoustic medium and the damaged laminated structures can be described by boundary integral equations assembled. For this case, i. e. a compressible fluid medium, the fluid pressure distribution satisfies Helmholtz's equation, the fluid impedance is mathematically complex, since it involves both mass - like and damping - like effects. From some typical examples, a good agreement between results of references and testing results provided in this paper, and it shows that the present analysis method and corresponding formulation for an acoustic eigen - problem of the damaged laminated structure are believable and effective. The method and numerical conclusion are valuable for clear understanding of dynamic behaviour for the delaminated composite laminated plates in the heavy fluid medium.
出处
《船舶力学》
EI
2001年第5期56-65,共10页
Journal of Ship Mechanics
基金
国家自然科学基金(59975014)
大连理工大学工业装备结构分析国家重点实验室开放基金资助
关键词
声音
振动
复合材料层合板
分层
重流体介质
有限元
边界元
声纳
舰艇
Acoustic wave effects
Finite element method
Laminated composites
Plates (structural components)
Structural loads
