Static Stability Study Of Single-layer Reticulated Shells With Opening At The Top

At present, the reticulated shell structure partial opening has become more and more common in engineering. To meet the building demand of architectural modeling and lighting in large-span gymnasiums, theaters, and exhibition hall, reticulated shell structure with top opening is also increasing. Nowadays,in our country provisions about the opening of reticulated shell structure are insufficient and research is also relatively not enough in this part. Mainly basing on a real opening reticulated shell structure and research demand of opening reticulated shell, this paper proposes to analyze static stability through the top opening of single-layer reticulated shell structure.Large general finite element software ANSYS is used in this paper, combining with the APDL parametric language, to establish a plurality of K8 type single-layer reticulated shell with opening modelchanging geometry parameters, and to calculate more than 15,000 cases of double nonlinear stability analysis. Finally, this paper puts forward a stability imperfection analysis method on single-layer reticulated shells with top opening, analyzes the influence of different parameters on opening reticulated shell structure and discusses the solutions of strengthening local opening. The main jobs are as follows:(1)In this paper,the double nonlinear calculation principle of the reticulated shell structure is simply introduced. Different K8 reticulated shell models by changing the variation of radius of opening and rise-to-span ratio are established by using ANSYS’s scripting language APDL.(2)Double nonlinear static stability analysis about K8 single-layer reticulated shell with opening is conducted largely by using random imperfection mode method, consistent imperfection mode method and N-order characteristic imperfection mode method for each opening reticulated shell model.Through the comparative analysis of three methods, explore the rationality of various methods.As a result, N-order characteristic imperfection method is suggested for stability analysis of opening single-layer reticulated shell.(3)The value of initial imperfections on single-layer reticulated shell structure with opening is discussed. In conclusion, the initial imperfection value of procedure ——1/300 of the span,is recommended procedures related to opening reticulated shell imperfection of the initial value of values, off for 1/300 of the span reticulated shell. Then this paper studies several basic parameters’ effect to reticulated shell with opening. This parameters include initial imperfection, rise-to-span ratio, and opening dimension.(4)For openings, this paper proposes the idea of strengthening opening’s local single-layer reticulated shell structure. Try to figure out the effects todifferent opening reticulated shell structures’ stability by changingaxial stiffness or flexural rigidity of the first top ring, the first two top ring,and the top radial rod changes.Finally, the paper puts forward the suggestion of strengthening the opening stiffness, which can effectively improve the bearing capacity of the reticulated shell and save steel.