The structural-acoustic interactions of a coupled multilayered composite cylindrical shell and internal equipment system immersed in an infinite fluid medium are analyzed. The internal equipment is installed on the cylindrical shell by a series of nonlinear compliant mounts, which are represented by nonlinear springs and linear viscous dampers. Both the translational and rotational vibrations of the internal equipment are considered, and they are strongly coupled together due to the nonlinear elastic mounts. The nonlinear dynamics model of the coupled cylindrical shell and internal equipment system is established using a modified variational method, and the fluid exterior to the shell is modeled by a time-domain boundary element method. A strongly coupled serially staggered procedure is adopted to solve the governing equations of the structural system and the acoustic fluid as a coupled system. The results of the present analysis are validated by comparing with those obtained from the finite element method. The nonlinear structural vibration and acoustic wave behaviors of the coupled system containing compliant mounts with linear or nonlinear stiffnesses (including quadratic, cubic, quartic, quadratic-quartic types of stiffness) are analyzed. The effects of the translational and rotational motions of the internal equipment as well as their coupling on the nonlinear vibration and acoustic wave responses of the coupled system are examined. Physical insights into the super-harmonics in the vibration and sound pressure responses of the coupled system are provided.

分析了耦合的多层复合圆柱壳和浸入无限流体介质中的内部设备系统的结构声相互作用。内部设备通过一系列非线性顺应性安装件安装在圆柱壳上，以非线性弹簧和线性粘性阻尼器为代表。考虑到内部设备的平移和旋转振动，并且由于非线性弹性安装，它们被牢固地耦合在一起。采用改进的变分法建立了圆柱壳与内部设备系统的非线性动力学模型，并采用时域边界元法对壳外部流体进行了建模。采用强耦合串联交错程序求解结构系统和作为耦合系统的声流体的控制方程。通过与从有限元方法获得的结果进行比较，可以验证本分析的结果。分析了包含线性或非线性刚度（包括二次，三次，四次，二次-二次型刚度）的柔顺安装座的耦合系统的非线性结构振动和声波行为。研究了内部设备的平移和旋转运动及其耦合对耦合系统的非线性振动和声波响应的影响。提供了对耦合系统的振动和声压响应中的超谐波的物理见解。