Shape Optimization Design And Building Energy Efficiency Of Spherical Dome Shell With Large Rise-span Ratio

With the development of the science and technology exhibition hall, dome theater, and other museums, spherical net shells over hemisphere have got the attention of some architects and structural engineers, because of its free grid form, uniform and reasonable mechanical performance, light weight and large stiffness, and widely applied to the engineering practice.Taking the spherical shell with large height-span ratio as the research object in this paper by means of the finite element software ANSYS, concrete research content are as follows:(1) According to the spherical reticulated shell node coordinates and the basic form of bar connection, five types of shell model including Ribbed, Schwedler, Lamella, Kiewitt and Geodesic patterned, were established by using ANSYS Parametric Design Language, and mechanical characteristics of these models were studied under uniformly distributed load, and the influence of half profile angle, grid parameters and patterns on the whole static performance was analyzed in detail.(2) The mathematical model between macroscopic parameters, including sphere radius R, half profile angle α, radial laps nx and ring fraction kn, and microscopic parameters, including bar length and the angle among elements, was built according to the Cosine law and the distance formula between two points, and could provide mathematic reference to the combinational design of spherical shell through controlling the grid parameters by giving bar length range.(3) The shape optimization design on Ribbed, Lamella, Kiewitt and Geodesic patterned spherical shell was carried out using two-stage sequence optimization algorithm in discrete variables, taking the total steel consumption of structure as objective function and the constraints including intensity, stiffness and stability of the structure into consideration. Through the analysis of hundreds of optimization numerical example result, the impact of the angle a, radial laps nx, ring fraction kn and grid forms on the total steel consumption was studied to provide a reference basis for the engineering practice.(4) Taking the ribbed spherical shell as an example, eigenvalue buckling analysis was carried out to get the first six order eigenvalues, buckling mode of the structure and the critical load at different profile angle. The consistent mode imperfection method was used in the nonlinear buckling analysis to get the load-displacement response curve and the ultimate bearing capacity of the shell with initial defects. And the influence of weak part of shell on the overall stability could provide a reference to structural design.(5) The spherical shell with large height-span ratio is used intensively in the architecture of dome theater and planetarium where the comfort of air conditioning is the same important as energy conservation. The simplified model of interior auditorium of theater was established in the GAMBIT software, the air distribution was simulated by the computational fluid dynamics software FLUENT under the new energy-saving displacement ventilation, and comfort assessment was evaluated to provide a reference to the air conditioning system design in the theater.