Estimations of Buckling Strength and Ultimate Strength of Single Layer Lattice Shells

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This study is projected for the purpose of collecting of the data on buckling strength and ultimate strength of single layer lattice shells with optional shapes. The outlines for the research results in 2002 and 2003 are shown below.Shape optimizations of single layer lattice shells were carried out for maximizing the linear buckling load and minimizing the difference between the maximum and minimum lengths among the specified members. As a result, while taking the linear buckling loads into consideration, the optimal shapes with few kind of member length were obtained. Smooth optimal shapes could be obtained by modeling the lattice shells using tensor product Bezier surface.The buckling behavior of HP (Hyperbolic Paraboloidal) lattice shells under uniform loadings was examined using the static elasto-plastic buckling analysis. HP lattice shell is a surface with a negative Gauss curvature. The initial yield load and the ultimate load were expressed in terms of column buckling strength, and the concept was applied to estimate the initial yield load and the ultimate load of HP lattice shells. In addition, the effects of loading imperfection and geometrical initial imperfection on the buckling behavior were made clear.On the single layer lattice shells with dome shape, the earthquake response behavior and the dynamic buckling behavior were examined. The CQC (Complete Quadratic Combination) method of response spectrum analysis was used. The response acceleration subjected to horizontal earthquake motions were evaluated. Based on the result, the static earthquake load for lattice dome was proposed. On the dynamic buckling analysis, the step wave and single pulse wave were adopted as input waveforms, the analysis method was the time history non-linear response analysis. The effects of the half subtended angle of the dome and the input direction on the dynamic buckling behavior were examined.