LNG储罐穹顶带钢板网壳施工全过程稳定性分析

Complete process analysis of reticulated dome with steel plates of LNG tank in the construction period

为分析带钢板网壳在穹顶混凝土施工全过程期间的稳定性能与承载能力,利用ANSYS有限元分析软件建立精细化有限元模型,对其进行非线性荷载-位移全过程分析,利用能量误差方法评估并确定合理的单元网格划分尺寸,通过获取屈曲临界点处的屈曲模态形式,确定带钢板网壳的合理初始几何缺陷形式;探讨了蒙皮钢板对网壳稳定承载力的影响,以及钢板厚度、网壳杆件截面尺寸、矢跨比、初始几何缺陷等参数对带钢板网壳稳定性能的影响规律.分析结果表明：钢板蒙皮显著提高了网壳承载力;1/8~1/5矢跨比范围内,随矢跨比的增加,结构极限承载力最大增幅可达87.3%;带钢板网壳对初始几何缺陷具有高度敏感性.

A finite element model was established to investigate the stability and bearing capacity of the reticulated dome with steel plates during the construction period of concrete dome using ANSYS. The meshing density was evaluated with the energy error. The nonlinear load？deflection complete process analysis was carried out. Taking the buckling mode at the critical point as initial geometric imperfection form of the dome, the stressed？skin effect on the dome was investigated. The effect of the steel plate thickness, beam section size, rise to span ratio and initial geometric imperfections on the stability of the reticulated dome was discussed. Analysis results show the stressed？skin effect on the dome is significant. The ultimate bearing capacity of structure increases with span ratio in the range of 1/8~1/5, while the maximum increment percentage is 87？3%. The reticulated dome with steel plates is highly sensitive with initial geometric imperfection.