单层球面网壳结构风致响应计算的块里兹向量法

单层球面网壳结构自振频率密集，且高阶模态可能对结构的风致响应有较大贡献。利用传统模态叠加法计算结构风致响应时需截取较多的模态，导致计算效率较低。本文提出的块里兹向量法所生成的向量都是被荷载所激发的，因此仅使用少数向量即可获得准确的响应结果。块里兹向量迭代所需的多荷载模式可以利用本征正交分解（POD）技术获得，这种技术将脉动风压场分解为与时间无关的协方差模态以及与空间位置无关的主坐标。根据风洞实验同步测量的风压数据，利用本文计算了0．1和0．2矢跨比的单层球面网壳的风致响应。通过与传统模态叠加法计算结果的对比分析说明了本文方法的有效性。

Block Ritz method of computation for wind-induced response of single-layer latticed domes

With a lot of natural frequencies distributed over a narrow range and obvious contributions attributed to some high-order modes,the computation of wind-induced response of the single-latticed domes requires much more modes in the traditional mode superposition.This leads to a lower efficiency of computation.All block vectors generated from the algorithm of the block Ritz vector method,that is proposed in this paper,are excited by external loads,thus accurate solutions of response can then be calculated with only few block vectors.The multiple load patterns,that is required by the iteration of the algorithm,may be obtained by using the proper orthogonal decomposition(POD) technique,through which the wind fluctuating pressure field is divided into the time invariant covariance modes and the spatial invariant principal coordinates.Meanwhile based on pressure data measured via wind tunnel tests,the wind-induced responses of single-latticed domes with the rise-span ratio of 0.1 and 0.2 are computed using the proposed method.The comparisons between the results with those obtained from the traditional mode-superposition method illustrated the effectiveness of the proposed method.