单桩海上风机灌浆连接的抗震性能研究

Seismic performance of grouted connections of monopile offshore wind turbines

在地震作用下,灌浆连接段的稳定性直接关系到风机结构的安全。为了探讨灌浆连接的抗震性能,文章以5 MW单桩风机为研究对象,采用OpenSees和ANSYS软件分别建立风机结构及灌浆连接有限元模型;以最不利的地震动为输入,同时考虑风和波浪耦合作用分析灌浆连接的受力及反应。结果表明,地震动使风机灌浆连接处产生较大荷载作用,容易使灌浆层出现高拉应力,导致灌浆材料拉裂,致使灌浆连接失效;地震动强度较小时,风和波浪荷载对灌浆连接受力影响较大,随着地震动强度增大,风和波浪的影响逐渐减弱。风机灌浆连接的抗震设计,应重点分析灌浆层的震动破坏,并充分考虑风和波浪的荷载效应。

The seismic stability of the grouted connections of offshore wind turbines is directly related to the safety of offshore wind turbines. To evaluate the seismic performance of grouted connections of offshore wind turbines,numerical models of a 5 MW monopile offshore wind turbine and the grouted connection were established using the OpenSees and ANSYS software packages, respectively. Design ground motions of the severest condition were used as input ground motions. The combinations of wind and wave loads were taken into account to analyze the internal loads and responses of the grouted connection. The results showed that earthquake ground motion resulted in large loads acting on the grouted connection,which introduced to high tensile stress in the grout layer leading to cracks in the grouting material and subsequently the failure of the grouted connection. In scenarios with less severe ground motions,the loads acting on the grouted connection were significantly influenced by the combination of wind and wave loads. The influence of the combination of wind and wave loads on the loads acting on the grouted connection decreased gradually as the intensity of ground motions increased. It is recommended that in seismic analysis,specific attentions should be paid to the grout layer of offshore wind turbines,and the effects of wind and wave loads should be considered.