单层脊线式叉筒网壳结构性能研究

Structural behavior of single-layer ridge-type intersected braced barrel vaults

对一组圆柱面网壳交叉组合形成的新型网壳结构———叉筒网壳中的单层脊线式叉筒网壳的结构性能进行了系统研究.运用有限元方法分析了该结构在对称与非对称荷载作用下的静力性能,并着重讨论了矢跨比、荷载工况、边界条件和几何初始缺陷对结构非线性稳定性能的影响.研究了不同矢跨比和不同屋面荷载作用下的结构自振特性,并比较了不同矢跨比结构在地震作用下的水平地震内力和竖向地震内力.研究结果表明,单层脊线式叉筒网壳受力性能良好,非对称荷载对结构性能的影响不大;矢跨比对结构的稳定极限荷载和动力性能影响较大;随几何初始缺陷的增大,结构稳定极限荷载平缓降低.

A type of lattice shell structure named intersected braced barrel vault which is formed by intersecting and combining a group of cylindrical lattice shells was proposed. The structural behavior of single-layer ridge-type intersected braced barrel vaults was analyzed. The static characteristics of this structure under symmetric and unsymmetric loading were studied, and the effects of rise-to-span ratios, load cases, boundary conditions and initial geometric imperfections on the nonlinear stability behavior were discussed. The natural vibration properties under different rise-to-span ratios and different roof loads were analyzed, and the horizontal and vertical seismic forces under different rise-to-span ratios were compared. Results from this study indicate that the intersected braced barrel vault has good load-bearing properties; unsymmetric loading has little influence on its structural behavior. The rise-to-span ratio has great influence on both the stability limit load and the dynamic property, and initial geometric imperfections lead to a slow reduction in the stability limit load.