平面拱形桁架等效静风荷载研究

Equivalent static wind loads on arched truss

对矢跨比分别为1/4、1/6、1/8的3个拱形屋面进行了同步测压风洞试验,分析风荷载和结构参数对平面拱形桁架风振响应和等效静风荷载的影响规律。风洞试验结果表明,0°风向时,高矢跨比屋面的最大负压幅值出现在屋顶,而低矢跨比的出现在迎风前缘。从方便工程应用的角度,采用简化振型函数表达针对结构多个位移和杆件应力响应的多目标等效静风荷载。在工程常用范围内,分析结构矢跨比、跨度、屋面质量、设计风速和风向等参数对中部和端部平面拱形桁架多目标等效静风荷载的影响,得到可用于指导该类结构抗风设计的等效静风荷载风压系数建议值,且经校核,在该等效静风荷载作用下的结构响应与实际动力响应极值吻合较好。

Wind tunnel tests were conducted on three arched roofs with different rise-to-span ratios （1/4,1/6 and 1/8 ）. The effects of the parameters of the wind loading and structures on the wind-induced response and equivalent static wind loads （ESWL） were investigated for arched trusses. The experimental results show that when the wind direction is 0°, the maximum suction occurs on the roof apex under high rise-to-span ratios, and at the leading roof edge under low rise-to-span ratios. For the engineering convenience, one simplified mode was chosen to express the ESWL for multiple nodal displacements and member stresses. This method was employed to investigate the effects of the rise-to-span ratio, span length, roof mass, wind velocity and wind direction on ESWLs of arched trusses in the middle and edge areas. Suggested values of ESWLs are proposed for engineering structural design. Structural responses under these ESWLs agree well with actual peak responses.