封闭式屋盖结构风致响应理论与试验

Wind-induced response theory and tests for closed type roof structures

为了研究封闭式屋盖结构的风致响应特性,用理论方法与风洞试验进行定性与定量分析.在传统模态分析法的基础上考虑结构内压与屋盖的耦合作用,推出了模态空间不独立的频响函数矩阵来描述屋盖的风致响应特性,通过算例分析了内压对封闭式屋盖风致响应的影响机理,并对钢网架平屋盖位移响应和加速度响应在内压影响下的变化进行了参数分析.采用预应力张拉结构体系设计制作了可调刚度屋盖结构的气动弹性模型,在风洞试验中进行屋盖加速度响应的测定,试验结果与理论分析结果较为吻合.研究结果表明,考虑内压后封闭式屋盖结构的风致响应会有所减小,而墙面孔隙率与气承刚度系数是影响封闭式屋盖风致响应的重要因素.

Theoretical method and wind tunnel tests were carried out to investigate wind - induced response for closed type roof structure. Considering the coupling effect of internal pressure and roof, a new frequency response matrix was deduced to describe wind - induced response characteristic for closed type roof structure. Numerical examples were provided to study the influence of internal pressure on wind - induced response of closed type roof structure, and quantify analysis was presented for a typical steel grid roof structure. Prestress stretching architecture was applied to design the aerodynamic model for closed type roof structure with adjusta- ble stiffness and wind - tunnel tests for wind - induced dynamic response of roof were conducted. The acceleration response results obtained from wind tunnel tests agree well with the theoretical ones. It is shown that the wind - induced response for closed type roof is reduced considering internal pressure, the wall porosity and the pneumatic stiffness coefficient have dominant effect on wind - induced response of closed type roof structure.