针对近海风机在风、波浪和地震3种载荷作用下的振动控制问题,提出了基于磁流变弹性体(magnetorheological elastomer,MRE)调谐质量阻尼器(tuned mass damper,TMD)的海上风机半主动控制方法.首先,介绍了MR E的变刚度磁致力学特性及面向海上减振需求的MR E-T MD结构设计原理;其次,建立了海上风机-T MD动力学模型,计算了风、波浪及地震激励载荷;再次,应用半主动控制算法跟踪识别风机塔筒顶端响应的频率,实时调节MRE-TMD的刚度,进而对海上风机进行振动控制.通过分析导管架式近海风机在多种载荷作用下的动力响应可知,采用基于MRE-TMD的控制方法能够有效衰减导管架式海上风机在多种载荷作用下的振动响应.与被动TMD相比,MRE-TMD具有较好的减振效果,为海上风机振动控制提供了一种新的解决思路.

With high flexibility and low damping, offshore wind turbines (OWTs) are prone to external vibrations such as wind, wave and earthquake, either attacked individually or as combined loading cases. This study proposes a semi-active variable-stiffness tuned mass damper (VSTMD) with magnetorheological elastomer (MRE) materials to mitigate undesired dynamic responses of OWT. A jacket supported OWT with MRE-TMD installed at the top of the tower is adopted as an example to demonstrate the effectiveness of the proposed design under multiple hazards. A semi-active frequency tracing algorithm is proposed through which the current-dependent stiffness of MRE-TMD is controlled by tracking the acceleration of OWT tower. The numerical results demonstrate that the semi-active MRE-TMD can effectively attenuate the dynamic responses of OWT under multi-hazard loadings, and it outperforms the passive TMD in reducing the peak and RMS displacements of tower structure. Robustness analysis of semi-active MRE-TMD is also validated by considering OWT sudden loss of partial stiffness under multiple-loadings.