有初始几何缺陷的双层柱面网壳结构地震反应分析

Earthquake analysis considering initial geometrical imperfection of double layer cylindrical lattice shells

有初始几何缺陷的双层柱面网壳结构其极限承载力及结构稳定性都有所降低,采用有限元分析软件ADINA对双层柱面网壳模型在无缺陷和有初始几何缺陷两种情况下,进行了地震反应分析对比,通过算例分析,在地震作用下其结构节点位移明显增大,个别节点位移增大近50%,且在指定频域内出现明显峰值,数值模拟证明双层柱面网壳结构的初始几何缺陷对结构抗震性能的影响是不能忽视的。通过对网壳结构进行特征值屈曲分析,以第一阶屈曲模态作为结构初始几何缺陷位置,得到了结构非线性分析的临界荷载量值,这对结构进行非线性分析提供了新的思路。

The authors give the earthquake analysis of double layer cylindrical lattice shells considering initial geometrical.Finite element analysis software ADINA is used separately to refer to the low step flexure model initial flaw model to the pilot model to carry on the contrast analysis,As a result of the initial flaw influence,the structure critical load dropped nearly 40%,under the earthquake the structure power displacement obviously increases,and in the frequency range the obvious peak value appears,which can cause the net shell to be easier to have the destruction.Therefore under the earthquake function,the double-decked cylinder network shell initial flaw can not be neglect to the structure earthquake resistance performance influence.Through the net shell structure,characteristic value of the first order are analyzed in buckling modes as initial geometric structure defect,the structure of the nonlinear analysis,the critical load of energy structure of nonlinear analysis provides a new idea.