大跨度单层球面网壳的损伤模型及强震失效

为对大跨度单层球面网壳在强震下的失效进行系统的分析,采用考虑材料损伤累积影响的全过程分析方法.考察了大跨度单层球面网壳在强震下失效时刻的多项响应指标随矢跨比、跨度、屋面质量等参数变化的规律,分析了失效极限荷载受这些参数变化的影响,同时讨论了考虑初始几何缺陷对结构失效特征的影响.通过分析发现,单层球面网壳在强震下基本属于动力强度破坏范畴,基于这些强度破坏算例失效时刻的特征响应,分别建立了理想网壳和缺陷网壳的强震损伤模型,可以表征结构在动力荷载下的损伤程度并判定强度破坏极限荷载.

The damage model and failure mechanism of long-span single-layer reticulated domes under earthquakes

The failure mechanism of long span single-layer reticulated domes subjected to severe earthquakes are studied which is applied on the full-range analysis method with the consideration of material accumulation. The responses of long span single-layer reticulated domes subjected to severe earthquakes are discussed with the influence of rise span ratio, span and roof load, and the change of failure ultimate load is described. The failure characteristic of domes with or without the consideration of geometric imperfections is discussed. Almost the failure mode of examples is dynamic strength failure while long span single-layer reticulated domes are subjected to severe earthquakes after distinguishing. The structural damage model of perfect domes and imperfect domes are fitted respectively based on the characteristic responses at failure state, which are used to indicate damage level of reticulated domes. The strength failure criterion is proposed to distinguish the ultimate load of earthquake failure.