Research On The Advanced Consistent Mode Imperfection Method For Single-layer Domes Stability Analysis

With the growing demand for life quality, how to make a large space without barrier in it becoming a very important part of modern design. Single-layer latticed shells got attention-getting as the excellent representation of large-span space structure in about last fifty years. The stability of latticed shells is most important in design. Limited by experiment environment in China, the depth-to-span ratio is always above 1:7. When people demand more beautiful shapes and larger space of buildings, shells have small depth-to-span ratio becoming more popular. But the influence to stability of shells have small depth-to-span ratio caused by initial imperfection in geometry is not deeply studied in China. It is necessary to begin study the stability of single-layer with small depth-to-span in depth.This paper gave a parametric analysis report of shells in common used by depth-to-span ratio, span, initial imperfection in four buckling mode. It got large number of valuable data through the full program nonlinear finite element analysis of shallow single-layer shells in 1350 cases and given a new way and method to design of shallow single-layer shells.It is shown that the stability of shallow single-layer shell is not just due to the first level of buckling mode. Initial imperfection in higher levels of buckling mode distributing always control the stability of single-layer shells that have small depth-to-span ratio and large span. This paper given an advanced consistent mode imperfection method for shallow latticed single-layer shells. It suggest that to analysis shallow latticed single-layer shells should consider coupling effect of multi buckling modes when multi buckling modes distributing is considered and given a simple formula to calculate the coupling effect.