engleski

Compound buckling and imperfection sensitivity of single layer reticulated dome

This paper deals with stability analysis of single layer reticulated dome and the influence of various buckling modes interaction. Load capacity of the lattice dome is limited by large slenderness and sensitivity to imperfections. According to the amplitude and the form of imperfections, the structure changes the bearing behaviour. The interaction of closely spaced buckling modes can reduce the load capacity of the structure and produce the compound buckling. The analyses are performed on two types of lattice grid, the triangular pattern and shifted triangular pattern. Both structures have a same span and height. Also, the weight of material per unit area is also similar. The load capacity and interaction of global forms of instability is observed. The local instability of single node or member is prevented. The several shapes of imperfections are used, which correspond to the first three eigenvectors for symmetric and asymmetric load. The set of amplitudes obtained are in accordance to the manufacturing and assembling tolerances. As a result, the equilibrium curves with precritical and postcritical regions are obtained. Further, the sensitivity curves are constructed. The equilibrium curves are obtained with finite element approach (Sap2000). The numerical simulations are performed on the spatial model using geometrically nonlinear dynamic analyses with large displacements and small strains. The material behaviour is assumed elastic.

reticulated single layer dome; compound buckling; nonlinear analyses; sensitivity surface; global instability; imperfection

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