海上风机灌浆连接段应力评价方法探析

A Stress Evaluation Method for Grouted Connections of Offshore Wind Turbines

[目的]灌浆连接段被广泛应用于海上风机支撑结构与基础的连接,其力学性能对整个风机的可靠性至关重要。为了探寻对灌浆连接段合适的应力评价方法,文章进行了有限元模拟分析。[方法]通过建立数值模型来探究灌浆连接段在给定的压弯荷载下的应力分布情况,提出用名义平均应力和应力相关系数的概念来评价其总体应力水平,最后研究了各种参数对连接段力学性能的影响,并确定了在各参数变化条件下应力相关系数的范围。[结果]参数分析的结果显示剪力键的位置对灌浆连接段钢管的Mises应力和浆体的Tresca应力有较大的影响。并且钢管的厚度与最大应力具有负相关性。同时发现,灌浆层的最大Tresca应力仅对自身厚度的变化较为敏感,而对钢管厚度变化不敏感。最后,根据参数分析确定的应力相关系数在3到6之间。[结论]参数分析结果可以为灌浆连接段设计提供参考,而应力相关系数能够被应用于初步评估灌浆连接段在联合荷载作用下的力学性能。

[Introduction]Grouted connections are widely used to connect the support structure and the foundation of offshore wind turbines.Therefore,their mechanical properties are very important to the reliability of the whole structure.In order to find a proper method to evaluate the stresses of grouted connections,numerical simulations were conducted.[Method]Numerical models were established to investigate the stress distribution of a grouted connection under given compression and bending loads.The conceptions of nominal average stress and stress correlation coefficient were then proposed,which were used to evaluate the overall stress level of the grouted connection.Moreover,parameter studies were carried out,and the range of stress correlation coefficients were determined.[Result]It was found that both the Mises stresses of steel tubes and Tresca stresses of the grout were dominated by the locations of shear keys in the grouted connection.And there was an inverse negative correlation between the thickness of steel pipes and the maximum stresses of them.At the same time,the maximum Tresca stresses of the grout were only sensitive to the change of its thickness rather than the change of the thickness of steel tubes.Finally,the stress correlation coefficients all fell between 3 to 6 according to the parametric studies.[Conclusion]The result of parametric studies can partly guide the preliminary designs of grouted connection,and the stress correlation coefficients can be used to approximately evaluate the mechanical properties of grouted connections under combined loads.