基于改进FBS理论的浮筏隔振系统计算方法

The Calculation Method of the Isolation System Based on the Improved FBS Theory

高精度的隔振系统计算方法是开展隔振系统特性分析和设计的基础。将汽车领域中的FBS理论方法引入到舰船浮筏隔振系统的动态特性估算中,并针对现有FBS方法仅考虑隔振器的刚度和阻尼特性,而没有计入隔振器质量影响的不足,利用隔振系统力平衡以及速度连续性条件,在原有FBS理论的基础上,推导基于隔振器阻抗矩阵的浮筏隔振系统动态特性计算公式,从理论上消除隔振器特性等效所带来的误差。模型试验表明,相对于现有的FBS方法,改进后的计算方法在中高频段具有更高的精度,满足工程应用的需求。

The high accuracy calculation method for an isolated system is the prerequisite of carrying out its analysis and design. In this paper, the FBS method, which has been widely used in the automobile industry to calculate the dynamic characteristics of ship isolation systems, is introduced. Aiming at the defects of the present FBS theory （which assumes the perfect condition of force balance and velocity continuity and only considers the stiffness and damping characteristics of the isolator but ignores the influence of the mass）, a research is performed to deduce the calculation formula for floating raft isolation systems based on the matrix of the isolator impedance, which eliminates the errors brought by the equivalent isolator characteristics theoretically. The model test indicates that the refined method has higher accuracy at high frequency, which satisfies the need of engineering applications.