塑料大棚结构风振响应规律研究

为研究塑料大棚结构的风振响应规律,提出了塑料大棚结构风振响应分析的被研究块体方法,推导了塑料大棚骨架结构单元段的段间内力计算公式,设计了被研究块体构成方式,构建骨架结构中被研究块体的力学模型,给出了被研究块体方法实现过程;采用等截面圆柱杆的波动传播算例,验证了方法的有效性。在同时考虑平均风和脉动风作用、仅考虑脉动风作用、仅考虑平均风作用的3种工况下,针对不同跨度塑料大棚骨架结构的风振响应进行时程分析,得到骨架结构的节点位移和截面应力空间最大值的出现位置。结果表明:节点位移和截面应力均为脉动风荷载作用的计算结果明显大于平均风荷载作用的计算结果。因此,塑料大棚结构的风振响应分析需要考虑脉动风荷载的作用。

Wind induced vibration response of plastic greenhouse structures

In order to study the wind induced vibration response of plastic greenhouses,the investigated lump method for analyzing the wind induced vibration response of plastic greenhouses was proposed.The calculation formulas for the internal forces of the segments of the plastic frame structure were deduced,and the composition of the investigated lump was designed.The mechanical model of the investigated lump in the skeletal structure was constructed,the process of the studied block method was given,and the wave propagation example of the equal section cylindrical rod was used to verify the effectiveness of the method.At the same time considering the mean wind and the fluctuating wind action,considering only the pulsating wind action and considering only the average wind action,the time history analysis of the wind induced vibration response of plastic greenhouses with different spans was performed to obtain the nodal displacement of the skeletal structure.And the location of the maximum value of the stress space in the section.The results showed that the calculated results of both the nodal displacement and the section stress are fluctuating wind loads and are significantly larger than the average wind loads.Therefore,the wind induced vibration response analysis of the plastic greenhouse structure needs to consider the role of pulsating wind loads.