| Cable membrane structure is a new form of spatial structure,representing the development level of building and material technology.Skeleton membrane is a kind of cable membrane structure,It is widely used in all kinds of long-span structures because of its light weight,good seismic performance,short construction period and economy.The external loads such as wind and snow are random and uncertain.these accidental,random inhomogeneous loads will cause deformation of the membrane surface,fold relaxation,and even tear,resulting in structural damage.Exploring the mechanical properties of membrane structure is helpful to popularize and apply this kind of structure.Based on the theory and numerical simulation,this paper draws a conclusion that it has certain reference value for engineering design of similar membrane structure.In order to meet the functional requirements of the building,the large span arch space pipe truss is used as the steel skeleton,and the tensioned membrane material is arranged on the skeleton to form a relatively regular and relatively flat closed structure.In this paper,taking the structure as the engineering background,using the steel structure design software 3D3 S,according to the current norms and theories,the membrane structure shape and stress analysis are studied theoretically and simulated.The main contents are as follows:(1)This thesis introduces the present situation and development prospect of membrane structure research,and determines the research content,method and technical route of this paper.The classification and characteristics of membrane structure,composition,classification and mechanical properties of membrane materials are described.(2)The deformation theory of membrane structure and nonlinear finite element method are expounded.(3)This thesis discusses the general situation of the project and the method of shape finding.The calculation model is established by using 3D3 S software.The form finding analysis is carried out by applying the initial pretension to the structure,and the minimum equilibrium surface is found through repeated calculation.The effects of initial pretension and tension stiffness on shape-finding were studied.The stress anddisplacement of the membrane surface after shape-finding were analyzed and the corresponding laws were summarized.(4)By using 3 D3 S software,the load analysis of the structure is carried out on the basis of finding shape,and the nonlinear deformation equation under load is established considering the geometric nonlinearity.According to the technical specification of membrane structure,Japanese design method and German design method,the nonlinear analysis of structures under different load combinations is carried out to study the stress and deformation of membrane surface,and three design methods are compared.(5)The effects of initial pretension,tensile stiffness and orthotropic properties of membrane on the mechanical properties of skeleton membrane structures were studied.The load-stress,load-displacement curves were drawn and the corresponding conclusions were obtained. |
