大跨开孔结构屋盖风致响应分析的多模态精细时程积分法

大跨空间结构在灾害天气时，风从孔口处涌入，屋盖容易在内、外压共同作用下产生破坏.结合模态解耦原理和精细时程积分法，提出了多模态精细时程积分法，并推导了大跨屋盖风致响应与风效应系数的计算公式.通过大跨屋盖刚性和气弹模型风洞试验，计算了屋盖的风致动力响应时程，其结果与有限元分析吻合，验证了多模态精细时程积分法的正确性.分析了大跨屋盖跨中位移平均值、位移均方根值和加速度均方根值的分布，得出了大跨屋盖风致破坏的机理，指出高阶振型对大跨屋盖结构的风致响应的贡献不可忽略.计算比较了在四周封闭和突然开孔2种情况下的荷载风效应系数和位移风效应系数，结果表明多模态精细时程积分法是一种高效、快速、准确的大跨屋盖风致响应计算方法.

Analysis on wind-induced dynamic response for long-span roof of opening structure by multi-modal precise time-integration method

The dynamics of long-span space structures to sudden opening and the responses of roofs under interaction of internal and external pressure were investigated.Based on mode decomposition theory,a multi-modal precise time-integration method(MMPTIM) combined with the rigid and aeroelastic model wind tunnel test was presented to estimate the wind-induced response of long-span roofs. The dynamic responses of long-span roof were analyzed in the time domain using the time history experimental data of wind pressures on the roof surface.The results agreed well with that of finite element method.Analytical results show that the contribution of higher vibration modes cannot be ignored in the analysis of wind-induced dynamic responses for long-span roofs.The gust loading factor and the gust displacement factor in the case of round close and sudden opening were also calculated and compared,respectively.Results showed that the multi-modal precise time-integration method is a valid method with higher efficiency,accuracy and fast calculation speed.