Shape Optimization And Stability Analysis Of Kiewitt Partial Double Ribbed Domes

Dome has a beautiful architectural style, whether in architecture, facade, or type body. It can give designers the creative freedom to the full. Shape can not be achieved with the grid structure, almost all the dome structure can do. This structure not only can performance static beauty,but also dynamic beauty by plane and cross cutting and the grid, supporting such changes and pole.Now, dome structure has been widely used in sports buildings, airport buildings, exhibition halls, industrial plants and other kinds of buildings.Partial double-ribbed dome is a single layer of a spherical dome,and it can combine the strengths of single-dome and double dome. In recent years,many forms of application of this dome appear. Because of uniform grid dome structure and rigidity, Kiewitt dome is the most widely used form of dome structure.But, Kiewitt spherical dome has poor stability and Kiewitt double spherical dome with a large number of bars and nodes has poor visual effects bar. According to the main power line transmission characteristics, aesthetic and economic indicators of construction demand of Dome structure,adding chords and belly bars in the bottom of the main rib of Kiewitt spherical dome, Kiewitt dome with partial double rib can be formed.It is a Double-dome local structure which is Reasonable force,Structure-performance, Simple and beautiful form,and ecomomical. Currently, Research priorities at home and abroad focus on optimization and application dome of Double dome and Stability and ultimate load of Single-layer dome,but the study of Partial double-ribbed dome System is seldom, especially in respect to the optimization of the shape.This paper studies primarily the partial double Kiewitt ribbed shell shape optimization. First, we use finite element analysis software ALGOR to analysis Static characteristics of the Kiewitt partial double ribbed dome,which has different span and the thickness of double area. With span ratio and thick span ratio changes, Force characteristics and displacement characteristics of dome can be obtained.It can provide the basis for selection of dome structure for the following initial macroscopic surface shape optimization parameters.Then, shape optimization of dome structure of the two algorithms accounted for the characteristics of spherical dome in this paper. FORTRAN language is adopted for writing program about the Sequential two-level algorithm of dome shape optimization,and connect to finite element analysis software named ALGOR. Using the optimized results of different span and types of dome show the validity and reliability of the algorithm. Then Shape Optimization of the dome, using the above algorithm,can get the optimal span ratios, the ratio of thickness to span the scope and parameters of surface macro-dome dome optimization results. In the double-dome ribbed local selection process, if the designer has identified to use Kiewitt partial double ribbed dome, these results can provide a reference value for selection macro-surface parameters for the dome, mesh size and bar section.With the development of structural optimization, the trend of optimization results is that the span is growing and Thickness is getting thin. At the same time, Stability of dome structures also become prominent.This paper use ALGOR to analysis of stability of optimized Kiewitt dome with partial double rib, including Eigenvalue buckling analysis,Nonlinear buckling of a rational analysis of dome and Initial defect of nonlinear buckling analysis. Buckling mode and Buckling load and the ratio of design load of optimized Kiewitt dome with partial double rib can be obtained. So,it can be used to evaluate the advantage and disadvantages of Dome optimization results.