断面风压作用下冷却塔塔筒内力影响线研究

Influence functions of internal forces of cooling tower shell under section wind pressure

为深入理解塔筒表面风压与塔筒内力的关系,以某大型双曲冷却塔为例,根据断面风压作用下内力影响线,分析了塔筒的受力特征,尤其是其子午向受力特征和断面风压的局部效应。从子午向轴力F_Y的影响面可知:在高度方向上,F_Y受到整个塔筒高度范围荷载的影响,表现出较为明显的空间结构受力特征;但在断面风压作用下,F_Y将只受其上部荷载的影响,表现出类似悬臂结构的受力特征。另外,不管是单位面荷载还是断面风压,其他内力如子午向弯矩M_Y、环向轴力F_X和环向弯矩M_X都表现出显著的局部效应。

Studies are conducted for further interpretation of the relationship between wind loads and wind-induced internal forces in hyperbolic cooling tower shell,and the main approaches are the influence surfaces under unit pressure and influence lines under section wind pressure.It is found that the influence surface of F_Y shows striking spatial effects and F_Y at any location is influenced by the pressure all along the shell height.However,F_Y would be influenced by the section wind pressure just above it,just like a cantilever beam.Moreover,other internal forces,the latitude axial force F_X,latitude moment M_X and meridian moment M_Y,all show striking local effect both for unit single pressure and section wind pressure.