摘要
结构鲁棒性体现了结构对局部破坏的不敏感性。为了定量评估钢框架结构的抗连续倒塌能力,提出一种适用于钢框架结构的鲁棒性定量评估方法。在综合考虑构件在结构能量流分布中的贡献和构件失效影响面积的基础上,给出构件重要性系数计算方法,为确定结构的最不利初始损伤模型奠定基础。探讨钢结构构件的承载能力冗余度,并结合构件应变能灵敏度,提出一个基于损伤模型的钢框架结构冗余度评估指标,该指标与构件的承载能力冗余度成正比,而与构件的应变能灵敏度成反比。从定义上对结构冗余度与结构鲁棒性之间的差异进行讨论,提出以结构最小冗余度作为评价结构鲁棒性能的观点。在此基础上,给出一种适用于钢框架结构的鲁棒性评估方法,同时对该方法的适用范围进行分析。最后,通过一个8层空间钢框架结构算例验证所提出的钢框架结构鲁棒性评估方法的可行性。
Structural robustness reflects the insensitivity of a structure system to local damages. To evaluate the progressive collapse resistance of steel frames, a quantitative assessment method for the robustness of steel frames is presented. By considering the contributions of structural members to the structural energy distribution and the influence areas of localized damage of structural members, a method for calculating the importance indices of members is given, which can be used to determine the most possibly unfavorable initial damage modes of a frame structure. By analyzing the steel member load capacity redundancy and the strain energy sensitivities of individual members, a structural redundancy index of steel frames is brought forward based on the localized damage modes, which is directly proportional to the member load capacity redundancy and inversely proportional to the member strain energy sensitivity. The minimum of the structural redundancy indices is employed to measure the robust performance of a steel frame, after discussing the differences in definition between structural redundancy and structural robustness. A quantitative assessment approach to structural robustness of steel frames in terms of damage mode based structural redundancy is proposed, and the scope of its application is then analyzed. Finally, an example of 8-story space steel frame is given to demonstrate the feasibility of the presented approach to evaluating the structural robustness of steel frames.
出处
《土木工程学报》
EI
CSCD
北大核心
2012年第9期46-54,共9页
China Civil Engineering Journal
基金
国家自然科学基金(50808116)
华南理工大学亚热带建筑科学国家重点实验室开放基金(2008KB25)
福州大学科研启动项目(022375)
关键词
构件重要性系数
结构冗余度
结构鲁棒性
钢框架
importance index of member
structural redundancy
structural robustness
steel frame
