静态与动态风荷载下连续焊接不锈钢屋面系统风致响应分析

Wind-induced Response Analyses of Long-span Continuous Welded Stainless Steel Roof System under Static and Dynamic Wind Loads

基于ANSYS软件平台建立了连续焊接不锈钢金属屋面体系的三维数值有限元计算模型,引入焊接不锈钢金属屋面抗风揭试验数据验证了所建模型的合理性,在动态和静态风载输入下结合该验证的数值计算模型调查了该屋面系统屋面板、支座构件的力学行为与变形机制。研究结果显示,动态风载输入下不锈钢金属屋面系统屋面板、支座的等效应力明显高于静态风荷载作用,在设计风压5.4 kPa风荷载作用下屋面板、支座的最大等效应力分别增长19.3%、54.1%,最大等效应力出现在支座列屋面板拐角处;结合输入风荷载和响应功率谱密度对比发现,动态风荷载对结构响应的放大效应主要集中在屋面系统基频处,说明在该频率区间内屋面系统产生了一定的共振效应,进而导致结构风振响应上升,在实际工程设计中应关注动态风荷载对结构响应的放大效应。

Finite element model of continuous welding stainless steel roofing system is built using the ANSYS platform. Based on the three-dimensional simulation model,the continuous welding stainless steel roofing model is verified with experimental data. The roofing system is compared and analyzed for equivalent stress and deformation of roof slabs,supports under static and dynamic wind loads. The results show that the equivalent stresses of the roof slabs and supports for this steel roof excited by the dynamic wind loads is larger than that under the static wind loads. Under the design wind pressure of 5.4 kPa,the maximum equivalent stresses increased by 11.46% and 48.45%,respectively. It can be found that the roof corner of the supporting column shows the maximum equivalent stress. Combined with the comparison of the input wind load and the response power spectral density,it is found that the amplification effect of the dynamic wind load on the structural response is mainly concentrated at the fundamental frequency of the roof system,indicating that the roof system has a certain resonance effect in this frequency interval,which leads to the structural response rises,attention should be paid to the amplification effect of dynamic wind loads on the structural response in actual engineering design.