Study on Buckling Design Methods of Single Layer Two Way Grid Lattice Shell

1. 对新开发的标准化桁架体系节点进行了处理，以便适用于单层双向网架壳。通过弯曲试验确定了材料的结构性能。1)力矩与转角的关系几乎近似为三线性。2)浇铸过程中，构件轴向力由受拉向受压转变，节理分离和屈服力矩增大。3)从数值结果来看，节点的刚度几乎取决于节点截面特性与圆管截面特性的比值。对以PC杆为斜构件的单层双向网架穹顶进行了屈曲试验。1) PC杆初始轴力与规定值对应。2)在PC杆初始轴力较大的情况下，屈曲载荷增大是可能的。3)离散处理方法适用于计算这些壳的屈曲行为。带PC杆的单层双向网格HP壳体承受中心载荷。考察了HP格壳的变形行为以及PC杆引入的初始轴向力的影响。采用离散处理方法对带PC杆和不带PC杆的单层双向网格壳进行了分析。1) PC筋的初始轴力为零，加PC筋的壳的屈曲载荷大多比不加PC筋的壳大1.5 ~ 3倍。2)当壳体划分数和PC杆初始轴力较大时，有PC杆的屈曲荷载与无PC杆的屈曲荷载之比增大。3)屈曲荷载与PC杆初始轴力之间存在三种关系。

1. The newly developed standardized truss system joint is treated in order to apply to single layer two-way grid shell. The structural properties were determined by the bending experiment. 1) The relation of moment to rotational angle is almost approximated to tri-linear. 2) The separation and the yield moment of joint increase in cast that the member axial force changes from tension to compression. 3) From the numerical results, the rigidity of joint is almost dependent on the ration of sectional property of joint to that of circular tube.2. The buckling experiments of single layer two way grid dome with PC bar as diagonal member are performed. 1) The initial axial forces of PC bars correspond to the specified value. 2) The increase of buckling load is possible in case that the initial axial force of PC bar is significant value. 3) The discrete treatment method is applicable to calculating the buckling behaviors of these shells.3. The single layer two way grid HP shell with PC bars is subjected under central loading. The deformation behavior of HP latticed shell and the effect of initial axial forces introduced by PC bars are examined.4. The single layer two way grid shells with and without PC bars were analyzed by the discrete treatment method. 1) The initial axial force of PC bars being zero, most of buckling loads of shells with PC bars are from 1.5 to 3 times larger than that of shells without PC bars. 2) When the division number of the shells and the initial axial forces of PC bars are larger, the ration of the buckling load with PC bars to that without PC bars becomes higher. 3) There are three kinds of relations of the buckling load to the initial axial force of PC bars.