对于开展高频天平测力试验的半刚性模型,在进行传统的频域内结构风振分析之前,需要对高频天平测力得到的试验数据进行修正。从达朗贝尔原理出发,通过假定原型塔架振型与物理模型振型之间的转换关系,运用模态叠加法,推导得出了半刚性模型天平测力数据的多阶广义风荷载谱修正公式。利用新得到的修正公式,发展了基于半刚性模型天平测力风洞试验的塔架结构风振分析方法。开展了某实际超大型锅炉塔架的天平测力风洞试验,对天平测力数据进行了修正,结合锅炉塔架的有限元模型,并完成了锅炉塔架的风振分析工作,验证了锅炉塔架设计的抗风安全性。
The model used in high-frequency-force-balance test must be light and rigid.How-ever,for lattice-truss structures,it is difficult to ensure rigidity of their wind tunnel models due to structural features and model fabrication limits.Force data of a semi-rigid model measured by a force balance needs to be modified before applying them in vibration analysis of the prototype structure.Based on D′Alembert′s principle and mode superposition method,assuming the trans-formation relation between the prototype mode and the modal mode,a new formula for modifying modal force spectra of a semi-rigid model was obtained.With the aid of the newly derived formu-la,the traditional frequency domain analysis method can be used to predict wind-induced response of a lattice-truss tower structure.The wind tunnel test was conducted for a large-scale tower in-stalled with a boiler.After applying the new formula,modal force spectra measured in the wind tunnel was corrected.Wind-induced response analysis was performed successfully for this tower structure.The results validated the adequacy of structural design of this tower in resisting wind storm.