摘要
对考虑P-Δ效应时结构的地震响应特征进行了研究.结果显示,考虑P-Δ效应后结构的整体刚度下降,几何非线性与材料非线性共同作用,使骨架曲线容易产生负刚度,利用三折线简化该骨架曲线较双折线更为准确.在此基础上,分析了带有负刚度的非线性弹性模型、完全弹塑性模型和Clough模型的滞回特征及其对结构抗倒塌能力的影响.算例结果表明:具有饱满滞回特征的完全弹塑性模型较容易出现偏振现象,表现出相对较小的抗倒塌能力;而具有完全或部分捏缩效应的非线性弹性模型和Clough模型的振动则具有较好的对称性,抗倒塌能力较强.这说明结构的抗倒塌能力并非仅与耗能能力有关,进入负刚度区域后的偏振现象才是引起倒塌的主要原因.
The characteristic of the seismic response of the structure with consideration of P-△ effect is studied. The numerical results show that the stiffness of the structure decreases when the P-△ effect is considered, and the backbone curve is easy to generate a negative slope when the geometric nonlinearity and the material nonlinearity are combined. The trilinear curve is more appropriate than the bilinear curve when simulating the characteristic of this backbone curve. On this basis, the hysteretic characteristics of the nonlinear elastic model, the full elasto-plastic model and the Clough model with a negative slope are analyzed, and the influence on the collapse resistance capacity of the structure are discussed. The results show that the displacement is more likely to concentrate on one side for the full elasto-plastic model with plump hysteretic loops, which results in a relatively lower collapse resistance capacity. On the contrary, the vibrations of the nonlinear elastic model and the Clough model with whole or part pinching are more symmetrical, and the corresponding collapse resistance capacities are better. It demonstrates that the collapse resistance capacity is not only related to the energy dissipation capacity of the structure. Rather, the biasing movement tendency when the structure goes into the negative post-yield stiffness branch is the main reason to cause structural collapse.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2013年第1期188-194,共7页
Journal of Southeast University：Natural Science Edition
基金
国家自然科学基金资助项目(51008077
51278105)
江苏省'青蓝工程'资助项目
江苏省土木工程博士研究生科技创新基金资助项目
关键词
倒塌
P-Δ效应
骨架曲线
滞回特征
collapse
P-△ effect
backbone curve
hysteretic characteristic
