大跨度单层球面网壳抗连续倒塌性能影响因素分析

Influence Factors on Progressive‑Collapse Resistance of Large‑span Single‑layer Latticed Domes

为分析大跨度单层球面网壳抗连续倒塌性能的影响因素,通过Keiwitt‑6(K6)型球面网壳缩尺模型的连续倒塌试验,验证有限元模型的正确性。在此基础上,分析了传力路径和初始缺陷对大跨度单层球面网壳抗连续倒塌性能的影响。研究结果表明,两个传力路径依次失效后,网壳主要通过压杆机制抵抗连续倒塌,其破坏模式为局部倒塌。有限元分析结果与试验结果吻合较好。传力路径与初始缺陷对网壳抗连续倒塌性能影响显著:传力路径依次失效时,结构的抗连续倒塌性能可以得到充分发挥,传力路径同时失效时,结构的动力响应明显增大;随着初始几何缺陷大小的增加,网壳的抗连续倒塌性能降低;当初始缺陷大小相同时,结构并非均是在第1阶屈曲模态下率先发生连续倒塌。建议考虑传力路径的影响,取前10阶屈曲模态进行网壳的连续倒塌分析。

In order to analyze the factors influencing the collapse resistance of large-span single-layer latticed domes,a scaled Kiewitt-6(K6)dome was tested and the finite element model was verified.On this basis,the effects of force transmission paths and initial imperfections on the progressive collapse resistance of large-span single-layer latticed domes were analyzed.The results indicate that after the two force transmission paths failed,the failure mode of the tested dome was local collapse.The dome relies mainly on the compression mechanism to resist progressive collapse.The finite element analysis results are well validated by the test results.The force transmission paths and initial imperfections have significant effects on the progressive collapse resistance of large-span single-layer latticed domes.When the force transmission path fails successively,the progressive collapse resistance of domes can be fully utilized.When the force transmission path fails at the same time,the dynamic response of the structure increases significantly.As the size of the initial imperfection increases,the progressive collapse resistance of domes decreases.When the size of the initial imperfection is identical,the progressive collapse of domes does not always occur firstly in the first-order buckling mode.It is recommended to consider the influence of the force transmission paths and take the first 10 buckling modes for analyzing the progressive collapse of domes.