基于动刚度法的桨-轴-壳耦合结构振动特性

Vibration Characteristics Analysis of Coupled Propeller-Shaft-Hull Structures Based on Dynamic Stiffness Method

桨-轴系统是水下航行器壳体振动与声辐射的主要激励源之一。文章建立桨-轴-壳耦合系统的动力学模型及分析方法,基于分块化建模思想,将耦合结构划分为桨-轴轴系及耦合壳体部分。在桨-轴部分中包含螺旋桨、轴以及轴承基座,分别用质量块、实心杆单元和弹簧-质量-阻尼系统模型,根据子单元连续条件,推导轴系部分动刚度矩阵。耦合壳体部分系统包含锥壳、圆柱壳、环肋板等构件,基于经典薄壳理论建立耦合壳体的动刚度模型。将轴承基座直接与组合壳体中艉部支撑端板连接,承载来自螺旋桨的纵向载荷,计算分析纵向载荷作用下轴系-艇体耦合结构的动力学响应特性。与有限元法计算结果相比较,验证了建模方法的正确性及可靠性。

The propeller-shaft system is one of the main excitation sources of vibration and sound radiation of shell of the underwater vehicle.The dynamic model and analysis method of the coupled propeller-shaft-shell system are established.Based on the idea of block modeling,the coupled structure is divided into two parts:propeller-shaft and coupled shell.The propeller-shaft part is composed of propeller,shaft and bearing base,which are modeled as mass block,rod and spring-mass-damping system,respectively.According to the boundary coordination relationship,the dynamic stiffness matrix of the shafting part can be derived.The coupled shell part consists of conical shell,cylindrical shell and annular plate.The dynamic stiffness model of the coupling shell is established based on the classical thin shell theory.The bearing base is directly connected with the stern end plate of the coupled shell to carry the longitudinal load from the propeller.The dynamic response characteristics of shafting-hull coupling structure under longitudinal load are calculated and analyzed.Compared with the finite element method,the correctness and reliability of the present modeling method are verified.