一种新型后张拉整体成型网壳动力性能分析

提出一种新型后张拉整体成型局部双层球面网壳的单弦杆平板网架模型,并通过有限元软件ANSYS建立有限元模型,采用BlockLanczos法对3组缝隙值对应成型后局部双层球面网壳进行模态分析,得到网壳的自振频率和振型,并与相应成型后在单层部分环向补杆网壳进行对比分析。结果表明:成型后网壳的各阶自振频率有随成型前预留缝隙值的增大而增大的趋势;在网壳的单层部分进行环向补杆能有效提高结构刚度,使补杆网壳的各阶自振频率与非补杆网壳相比有显著提高。此外,补杆网壳与非补杆网壳都表现出复杂的动力性能,在进行网壳的动力响应分析时应特别注意。

THE STUDY ON DYNAMIC PERFORMANCE OF A NEW RETICULATED SHELL SHAPED BY POST-TENSIONING

A new single-chorded plane space truss model of the partial double-layer spherical reticulated shell shaped by post-tensioning is put forward. Finite element models are created by finite element software ANSYS. Modal analysis of partial double-layer spherical reticulated shells shaped by post-tensioning with 3 pairs of gaps are carried out, which is compared with that of the corresponding reticulated shells which are circumferentially reinforced in the single layer section. The natural frequencies and mode shapes of the new reticulated shell with the ones of the reinforced reticulated shell are obtained by modal analysis. Analysis shows that the different orders of the natural frequency of the shell after forming are generally increase with the increasing of the gap value, circumferential reinforcing in the single layer section of the shell can effectively improve the stiffness of the structure and make the natural frequency of the order of the shell after forming significantly increase as compared with that of the non-reinforced shell. Furthermore,both reinforced shells and non-reinforced shells show a complicated dynamic performance,so much attention should be paid to the dynamic response analysis of the shell.