屋盖结构分区-多目标等效静风荷载方法研究  

Research on Partition-Multi-Objective Equivalent Static Wind Load Method for Roof Structure

作　　者：李云 张先龙 刘洋 张佳武 冯若强[2] Yun Li;Xianlong Zhang;Yang Liu;Jiawu Zhang;Ruoqiang Feng(China Construction Seventh Engineering Bureau(Shanghai)Co.,Ltd.,Shanghai 201800,China;School of Civil Engineering,Southeast University,Nanjing 150018,China)

机构地区：[1]中建七局(上海)有限公司,上海201800 [2]东南大学土木工程学院,南京150018

出　　处：《钢结构（中英文）》2022年第2期22-29,共8页Steel Construction（Chinese & English）

摘　　要：屋盖结构造型独特各异,具有重量轻、跨度大、刚度低等特点,结构对风荷载敏感。在该类结构设计中,风荷载往往起主要控制作用。另外,结构节点杆件众多,所关心的目标响应也很多,传统的单目标等效方法难以实现对多个响应的等效。针对屋盖结构控制点不明确、等效静风荷载不确定性等特点,提出了分区-多目标方法。该方法基于屋盖结构形态及测点平均风压系数结果进行分区,以少量的分区脉动风压为荷载分布基本向量。当采用多目标等效理论计算等效静风荷载,尽管能保证目标响应的等效,但等效静风荷载的分布可能不甚合理,在局部区域存在远超实际情况的静风压。因此,为了保证分区等效静风压分布的合理性,引入权重因子,通过求解约束方程的最小值确定等效静风荷载的分布。为验证等效静风荷载的计算精度,假设时程分析法计算的风振响应为精确值,将分区多目标法计算风振响应的结果与时程分析法比较,进行误差分析。最后以屋盖结构实际工程为例,分析了所提出的分区-多目标方法的等效响应精度及适用性。通过分析得到以下结论:1)针对屋盖结构实际工程的多目标等效静风荷载,未构造约束条件的多目标等效方法的等效响应精度最高,整体误差最小。但往往存在不合理的极值风压,风压变化剧烈且集中,不适用于实际工程应用,需对多目标等效方程构造约束条件。2)对多目标等效方程设置约束条件后,整体等效响应精度比未约束的多目标方法略有下降,但在可接受范围内,等效风压极值得到了有效的约束,风压变化平缓。设置关键等效目标的加权约束多目标方法中,关键目标的等效响应与风振响应吻合良好,且能进一步改善等效风压分布形式。3)实际应用时可采用分布系数对分区脉动风压进行约束,一般取峰值因子为分布系数约束范围,或可适当�The roof structure has the characteristics of light weight, large span and low stiffness, which makes it sensitive to wind load. In this kind of structural design, wind load often plays a major control role. In addition, there are many members in structural joints, and many target responses are concerned. Consequently, the traditional single-objective equivalent method is difficult to achieve the equivalent of multiple responses. In view of the uncertainty of the control points and the equivalent static wind load of the roof structure, a partition-multi-objective method is proposed in this paper. The partition is based on the roof structure shape and the average wind pressure coefficient of the measuring point. A small amount of partition fluctuating wind pressure is used as the basic vector of the load distribution. When the equivalent static wind load is calculated using the multi-objective equivalence theory, the equivalence of the target response can be ensured. However, the distribution of the equivalent static wind load may be unreasonable, and the static wind pressure in the local area may be far beyond the actual situation. Therefore, in order to ensure the reasonableness of the partition equivalent static wind pressure distribution, the weighting factor is introduced to determine the distribution of equivalent static wind loads by solving the minimum of constraint equation. In this paper, the wind vibration response calculated by the time-history method is assumed as the accurate value, which is compared with the vibration response calculated by the partition-multi-objective method to verify the calculation accuracy. Finally, taking the practical engineering of roof structure as an example, the equivalent response accuracy and applicability of the proposed method are analyzed. Conclusions are drawn as following: 1) For the multi-objective equivalent static wind load of the actual roof structure, the multi-objective equivalent method without constraint conditions has the highest equivalent response accura

关 键 词：屋盖结构 等效静风荷载 分区-多目标等效 加权约束方程 

分 类 号：TU312.1[建筑科学—结构工程]