Research On Nonlinear Stability Of Egg Circular Curved Single-Layer Reticulated Shell

With the continuous development of our country,more and more spatial structures in different shapes are emerging.Among which,the reticulated shell structure is a decisive and important structural form in the large span spatial structure.The force of reticulated shell structure is mainly the film force inside the surface,of which the rod piece mainly bears the axial force,and the structural force is reasonable.Meanwhile,it can adapt well to the large span and the material is light weight.is mainly the thin film force inside the surface,the structure is reasonable,and it can adapt well to the large span and the adopted material with light weight.All above mentioned characteristics make the reticulated shell structure widely used worldwide.However,the stability of single-layer reticulated shell structure is especially prominent,so the stability is the key point to be studied during the design of reticulated shell structure.The changeable shape of the reticulated shell structure is embodied in the diversity of its curved surface,in traditional,there are cylindrical surface,spherical surface and hyperbolic paraboloid.This paper takes single-layer reticulated shell structure in the form of egg circular curved surface as the research object,using MATLAB to divide its chord length,and then the parameterized modeling is performed with the adoption of finite element software ANSYS,so as to carry out the static force and stability analysis of this structure.This paper firstly introduced the egg circular curved surface and the relation with ellipsoidal surface.Then,contrastive analysis and parametric analysis are implemented on two forms of single-layer reticulated shell egg circular surface and static property of ellipsoid single-layer reticulated shell structure in ellipsoidal surface,which mainly include the internal force distribution and deformation law and horizontal support reaction.First of all,only considering the structural geometric nonlinearity on the basis understanding and mastering the static property of single-layer reticulated shell of egg circular curved surface,buckling mode of the structure was analyzed under the different load conditions;Then the influence of various parameters on the stability of the structure was studied,including the influence of the built-in constant k of egg circular curved surface and that of interchange between long axis and minor axis on the stability of single-layer reticulated shell of egg circular curved surface.Finally,the further study is carried out on the influence of double nonlinear under the simultaneous consideration of geometric nonlinearity and material nonlinearity to the stability of the structure.At the end of the paper,the local double-deck truss was placed into single-layer reticulated shell of egg circular curved surface to strengthen the stability of the reticulated shell structure,the form of which has ring direction arranged truss and radial arranged truss.After that,the effect of these three kinds of strengthen schemes on structural stability was compared and the o ptimal layout plan is selected.Finally,the optimal reinforcement scheme was adopted to study the rule of stability of the structure with the variation of truss thickness,and the optimum thickness was selected.The reticulated shell structure in new curved forms proposed by this paper and the study on its stability will provide some theoretical guidance for the subsequent research work and offer some basis for engineering application.