板片空间结构初始缺陷的动力稳定性影响分析

对板片空间结构体系的研究大都局限于静力载荷工况，结构在动力载荷作用下的稳定性及失效特征研究仍相对缺乏．板片空间钢结构先天存在各样缺陷，而缺陷对结构稳定性的影响不可忽略．本文引入拉丁超立方法，结合Budiansky-Roth 准则，提出适用于求解含初始缺陷结构动力临界荷载的方法，对板片空间结构初始缺陷的动力稳定性开展研究．研究表明，相比于其它抽样方法，拉丁超立方法能显著减少样本数，有效提高计算效率．针对典型的板片空间结构，施加不同方向的阶跃荷载，分析了节点位置偏差缺陷、杆件截面尺寸缺陷以及板片厚度缺陷对板片空间结构临界承载力的影响．结果显示，节点位置偏差缺陷对该结构临界承载力影响最为显著，其它两类缺陷影响甚微．

Influences of Initial Imperfection on the Dynamic Stability of Sheet Space Structures

Researches on sheet space structures are mostly limited to static load cases. Efforts on structures under dynamic loads are rather scarce. Initial imperfection inevitably exists in sheet space structures. Effects of the imperfection on the structural stability can not be ignored. By combining the Latin hyper-cube sampling method and Budiansky-Roth criterion, a procedure for solving the critical dynamic load of the structures with imperfection is proposed. Dynamic stability analysis on the sheet space structures are carried out. The results show that, compared with other existing methods, the proposed method can significantly reduce the number of samples, leading to improvement of the computational efficiency. A typical case of the sheet space structure under a variety of step loads is studied. The influences of imperfections in the nodal position, sectional areas and the sheet thickness on the critical structural bearing loads are investigated. The results show that, imperfection in nodal position has an appreciable influence on the critical structural bearing capacity, while effects of the other two factors are rather negligible.