【摘要】 提出一种基于节点方差比用于风力场重建的模态截断准则。所定义的方差比刻画了各个节点上的脉动风力方差的近似程度。方差比的收敛速度不仅取决于本征特征值而且取决于节点的位置。另外,提出以方差补偿技术改善风致响应计算精度。根据风洞试验和高频压力积分技术得到的风荷载,应用所提出的模态截断准则和方差补充技术重建了一球壳屋盖的风力场,讨论了新的模态截断准则在确定屋盖结构风致响应中的有效性。更多还原

【Abstract】 Proper orthogonal decomposition technique provides a unique tool for the data compression which facilitates reduced-order modeling of large-size random fields.The accumulated energy ratio is usually employed as the mode truncation criteria in the reconstruction of fluctuating wind force fields.However,this ratio can only describes the approximation of the total variance of the reconstructed wind force field.With the increase of the retained proper modes,solutions of wind-induced structural responses for some nodes are only converged rapidly.A mode truncation criteria based on the variance ratio of nodes is proposed for reconstructing fluctuating wind force fields.The defined variance ratio characterizes the approximation of the variance of fluctuating wind force in each node.The convergence of the variance ratio depends on not only the distributions of proper eigenvalues but the location of nodes.Moreover,a variance compensation technique is presented to improve calculation accuracy of wind-induced responses.The proposed mode truncation criteria and variance compensation technique are applied to the reconstruction of wind load field acting on a spherical roof,the original wind loads of which are obtained from the high frequency pressure integral technique in wind tunnel tests.The effectiveness of the new mode truncation criteria for determining wind-reduced responses of roof structures is discussed.更多还原