强震下弦支穹顶结构的动力失效探讨

为了揭示强震下弦支穹顶结构的动力失效机理,分别采用双线性本构模型和应变-损伤耦合本构模型,对一个8点支承的弦支穹顶结构进行了不同地震加速度下的全过程动力时程分析,考察了2种不同材料模型下的结构动力失效.同时对采用应变-损伤耦合本构模型的结构进行了深入研究,对该结构最大位移、塑性杆件数、杆件的应变能密度和动能密度、构件应力及应力变化率等多个物理量准则进行了考察分析.结果表明:采用应变-损伤耦合本构模型能更加准确地反映结构的动力失效,且这些物理量都能大致反映结构动力失效过程中的失效时刻;同时也反映了失效时结构最大位移、杆件塑性发展、索力松弛等失效特征.

Research on dynamic failure of suspend dome structures under severe earthquakes

In order to reveal the dynamic failure mechanism of suspend-dome structures under severe earthquakes, the dynamic time history responses for an eight points supporting suspend-dome subjected to different seismic acceleration excitations were investigated by using bilinear constitutive model and strain damage constitutive model respectively. Further researches on adopting strain damage constitutive model to simulate the dynamic responses of the suspend dome structures were implemented. Some physical quantities of the suspend dome structures, such as the maximal displacement, the number of plastic members, strain energy and kinetic energy density of members, stress and stress change rate, were taken for the dynamic failure criteria and analyzed. The results show that it is more accurate by utilizing the strain damage constitutive model than the bilinear constitutive model in the simulation of the dynamic failure. All the above physical quantities can roughly reflect when the dynamic failure happens. Also the results present some failure characteristics, such as maximal displacement, plastic development, and cables relaxation etc.