考虑地震损伤的单层球面网壳结构静力稳定性

为了研究地震损伤对单层网壳结构静力稳定性能的影响,基于考虑材料损伤累积效应的本构模型,对一K8型单层球面网壳结构,首先利用动态增量(incremental dynamic analysis,IDA)方法对单层网壳结构进行动力稳定分析,提出将B-R准则与塑性应变能曲线相结合作为结构动力失稳破坏的判断准则,得到结构动力失稳临界值;然后采用弧长法和Newton-Raphson法相结合的增量迭代法对损伤后的结构进行非线性屈曲分析,得到震后结构的静力稳定临界荷载.结果表明:考虑地震损伤累积效应的结构静力稳定性能显著降低,为该类结构抗震设计、性能评估和震后修复、加固提供参考.

Static Stability of Single-layer Latticed Shells Considering Damage Due to Earthquake

To study the effect on the static performance of single-layer latticed shells under earthquake damage, based on the material constructive relationship considering damage cumulative effect, the dynamic stable analysis is first carried out for a K8 type and single-layer latticed shell through the incremental dynamic analysis ( IDA) method, in which B-R kinetic criterion in combination with plastic strain energy density is put forward as the criterion for judging dynamic instability of single-layer latticed shells, from which the dynamic critical load value can be derived. Then, nonlinear buckling analysis by the arc-length method combined with Newton-Raphson method is done to the damaged structure due to earthquake, from which the static critical load value can be derived. Results show that the reduction to the structural static stable ability will be obvious after considering damage accumulation effect for single-layer latticed shells, which can be a reference for the structural seismic design, performance assessment, and engineering repair or reinforcement after earthquake.