板结构多模态动力吸振设计方法

Design Method of Multimode Dynamic Vibration Absorption for Plate Structure

针对海洋平台动力吸振研究中存在的多模态耦合振动吸振效果差的问题,研究抑制平台板结构振动的动力吸振器的设计方法。以薄板为具体研究对象,建立薄板与动力吸振器的数学模型,分析动力吸振器质量比的选择问题,讨论在离散模态和密集模态两种情况下动力吸振器的最佳安装位置,给出动力吸振器阻尼比和频率比的优化设计公式。在上述研究基础上,总结平台板结构动力吸振方法。以一个舱室仿真模型为应用对象,对参与舱壁振动的5阶模态进行振动控制,减振效果最高为92.2%。对动力吸振器进行补正设计后,针对第一、第五阶模态的减振效果分别提升0.9个百分点和6.1个百分点。上述结果验证了平台板结构动力吸振方法的有效性,该方法对海洋平台的振动防护具有一定的指导意义。

In order to solve the problem of poor vibration absorption effect of multi-modal coupling vibration in the study of dynamic vibration absorption of offshore platform,the design method of Dynamic Vibration Absorber(DVA)for suppressing the vibration of platform plate structure is studied.Taken thin plate as the specific research object,the mathematical model of thin plate and DVA is established,the selection of mass ratio of DVA is analyzed,the optimal installation position of DVA in discrete mode and dense mode is discussed,and the optimal design formulae of damping ratio and frequency ratio of DVA are given.Based on the above research,the dynamic vibration absorption method of plate structure on platform is summarized.Taken a cabin simulation model as the application object,the vibration control of the five modes involved in bulkhead vibration is carried out,and the maximum vibration reduction effect is 92.2%.After the modification and design of the DVA,the vibration reduction effect of the first and fifth modes is improved by 0.9 percentage points and 6.1 percentage points,respectively.The above results verify the effectiveness of the dynamic vibration absorption method of platform structure,which is of certain guiding significance for vibration protection of offshore platforms.