考虑结点耗能的导管架平台的动力响应分析

Dynamic response of jacket platform considering connection dampers

为了降低导管架平台的动力响应,可在导管架平台的连接结点之间加入能量耗散材料。本文以将管接点和能量耗散材料理想化为由转动弹簧和转动阻尼器并联组成的等效单元,结合有限元和动力刚度法推导了其刚度、质量和阻尼矩阵。采用复模态分析和虚拟激励法分析了三维导管架平台的动力特性和随机地震响应,讨论了刚度系数和转动阻尼系数对动力特性和减震效果的影响。算例结果表明,适当选择转动阻尼系数可显著增加结构模态阻尼比和降低结构地震响应。此单元可方便地与通用的结构有限元程序配合,对三维平台结构进行动力分析。

To reduce dynamic response of a jacket platform, energy dissipation materials may be placed between the tube joints. An equivalent element model is established by idealizing tube joints and energy dissipation materials as rotational spring and damper respectively. This paper derives the stiffness matrix, mass matrix and damping matrix of the equivalent element using a combination of the finite element method and the direct stiffness method. The complex modal analysis is carried out to determine dynamic characteristics of the jacket platform, and a generalized pseudo-excitation method is performed to analyse the responses of the jacket platform subjected by earthquake excitation. The effects of connection stiffness and rotational damper on dynamic characteristics and the seismic performance of the jacket platform are discussed. The parametric studies on the example jacket platform with and without the connection dampers show that there is an optimal damper damping coefficient by which the modal-damping ratio of the jacket platform can be greatly increased and the seismic responses can be significantly reduced.