80 m球径螺栓球节点单层球面网壳强震失效机理

为探究半刚性节点单层球面网壳在强震作用下的失效机理,以沈北新区80 m球径螺栓球节点单层球面网壳为研究对象,采用通用有限元软件ANSYS,引入节点试验和数值分析数据来模拟实际工程中螺栓球节点的抗弯性能,建立可考虑节点实际连接刚度的精细化数值模型,并进一步考虑局部杆件和节点加强、壳体外表面安装维护材料等不同结构条件的变化,在此基础上,对其开展强震作用下的失效机理研究.分析结果表明:沈北新区80 m球径螺栓球节点单层球面网壳的失效机理为局部节点瞬时大量破坏导致的结构动力失稳倒塌.局部加固网壳只能改善结构正常使用状态的各项响应指标,无法提高结构极限承载力.在现有结构表面安装维护面板,其各项响应指标(位移、支座反力等)皆明显增大,极限承载力下降57.1%,抗震能力明显降低.

Failure mechanism of an 80 meters span single-layer reticulated dome with bolt-ball joints subjected to severe earthquakes

Taking an 80-meters-span singer-layer reticulated dome which have been constructed in the Shenbei New District as an example, the failure mechanism of the singer-layer reticulated dome under severe earthquakes were analyzed with the FE software ANSYS. Based on the data of the numerical analysis and the test of the joints, the bending performance of bolt-ball joints were obtained and introduced into the numerical analysis considering the joint stiffness. Different structure models were established to investigate the effect of structure model changes, including the strengthening the local members and joints and installing maintenance materials on the surface of the structure. The analysis indicates that the failure mechanism of this structure is the collapse due to the dynamic instability of the structures while the local joints are damaged instantaneously and massively. The reinforcement of the reticulated dome merely improves the behavior of the structures in normal service condition, but it cannot improve the ultimate bearing capacity. The seismic response including displacement and support reaction increase obviously by installing maintenance panels on the existing surface, while the ultimate bearing capacity of the structures reduces by 57.1% and its seismic capacity decreases largely.