浮筏隔振系统隔振性能优化设计研究

建立了板式浮筏隔振系统有限元模型,用有限元直接法计算了隔振系统对动力学激励的加速度响应,以中间筏架各局部厚度为设计变量,以中间筏架重量为约束,以减小弹性基础振动、增加振动隔离为目标建立了优化数学模型,用可行方向法实现了隔振系统的优化设计。实例结果表明,隔振系统的优化设计可在筏架重量不增加、通过重新分布筏架的重量就可以减小基础的振动,增加浮筏系统的隔振性能;优化后基础的振动显著降低,极大地提高了隔振系统的隔振性能。

Optimization Design on Vibration Isolation Charaeteristics ofFloating Raft System

The floating raft system is more and more used in ship powerplant for reducing vibration and noise, it is that the multi-equipments are installed on the same vibration isolating system with the double layer isolators and a middle raft frame. The optimization design on float raft system is significant for advancing the design level and enhancing the vibration isolating performance. The finite element model of floating raft system is set up, the system modal is computed , and the vibration feature is determined by the use of the direct finite element method. Then, a optimization model is formulated for enhancing vibration isolating performance, the local thicknesses of middle raft frame are taken as design variables, the weight of middle raft fram is taken as constraints, the response accelations on base of floating raft system are taken as objection, the optimization problem is solved by the feasible direction method. A example optimization is achieved, the example results show that the vibration isolating performance is greatly enhanced by thickness redistribution of middle raft frame while the weight is not added.