STABILITY ANALYSIS ON LONG-SPAN SPHERICAL SUSPEN-DOMES OF LOW RISE-SPAN RATIO

摘要

In order to accurately grasp the overall stability of long-span spherical suspen-dome (LSSD) with low risespan ratio, a typical steel roof structure of a stadium is calculated and analyzed. The effect of prestressed cable-strut system and initial geometric imperfection on the overall stability is studied. The suspen-dome structure is compared with the steel lattice shell by removing the cable-strut system, including the linear and geometrical nonlinear stability. The role of the prestressed cable-strut system and the controlling failure mode are also studied. Results shows that the prestressed cablestrut system increases the overall stability and reduces the sensitivity to initial geometric imperfections of the suspen-dome, while it had little effect on the structural stiffness, linear buckling load, the nonlinear buckling capacity of initial nonimperfection, and buckling modes. LSSD of low risespan ratio is still sensitive to the initial imperfections and stability is still one of the controlling factors for structural design. In addition, live load distribution has little effect on the buckling mode as the structural arrangement is spherical. Therefore, full-span live load could be taken as the most unfavorable arrangement of live load.