Finite Elemen Analysis Of Static Properities Of A Cable-stayed Space Truss Station Canopy

Cable-stayed space truss is the structure composed of three basic parts,such as Stayed cables,space truss and tower.Compared with the cable-stayed latticed structure, it has less members and joints.It is easier to construction and lighter-styled.It is a promising structure.On the basis of the existing documents,this paper has done the following research on the current existing problems in cable-stayed space truss.This paper describes the type of structural configuration in detail and discusses the theory of geometric nonlinearity.The nonlinear stiffness matrixes of elements are deduced,which contain a cable element,a 3-dimension bar element and a 3-d beam element.Based on the analyzing method of Cable-stayed bridges,this paper puts forward an analyzing method of the prestressing of cable-stayed space truss,that is,the proved double circulate iterative method which are composed of equilibrium iteration and shape iteration was used to solve it.This method is used in a station canopy which is cable-stayed space truss and the model of 3-dimensional finite element is set up.The static properities of it was analyzed.The results show that double circulate iterative method posed in this paper is an efficient method.And the methods applied to prestressing.in construction was introduced in detailed.This paper makes an elaborate introduction of the design in all kinds of joints of cable-stayed space truss.The influence of fixed joint by welding directly and flexible joint by connecting ball in the connection of space truss and and tower on the performance is researched mainly.The results show that there is no great influence on deflection of the whole structure and internal forces of tower by the tower joints condition.Only stress of members near the joints has been changed.Farther the tower joints is,less obvious the change will be.In the case of guaranteeing the quality of construction,it will be more reasonable to adopt fixed joint.Then the stress of tower has been ameliorated after replacing the structure with deck one.Some factors affecting the performance of structure are studied,such as heights of tower column,ratio of rise to span of truss,stiffness of cables.At last,some referential suggestions to choosing the parameter in the process of design are put forward.