The Form-finding Analysis And Calculation Of The Tensioned Cable-membrane Structures

As a new-type building structure, the cable-membrane structure has lots of merits such as rational mechanical performance, high efficiency, novel modeling and favorable economy, etc. and demonstrates the enormous vitality and wide application prospect.In this thesis, the form-finding analysis of tensile cable-membrane structures is studied primarily. The emphases are put upon as follows:Based on the formulae form transformation is done, are acquired. According to obtained above and the results a serves of theoretically equivalent which are more suit for programming are acquired. The core calculation part of this program use VC++ language. This program is an object-oriented program with freedom point class, fix point class, branch-point class, force density class and so on.The detailed example analyses are done. on tensile cable-membrane structures of actual engineering, and the corresponding result data are shown as figures by using the data-processing software- ANSYS. The consequence of the example analyses proves the correctness and the usefulness of the program given by this paper. Analysis some electrophoresis of the form-finding result, we can open out the inherent rules and correlate qualities in the form-finding of tension cable-membrane structure.The tensioned cable-membrane structure is analyzed and designed by using ANSYS. After having established the analysis model of cable-membrane structure and selected the type of element, taking the number of mesh, pretension value, time step and convergence tolerance as design variables of optimization, least area or weight of membrane as object function, maximum and minimum stresses and node displacements of membrane surface as state variables, the optimization of form-finding is done. As compared with professional software, the result of both is very close and calculation error is within engineering permission.There are many problems on finding-form of cable-membrane with ANSYS: 1.ANSYS's theory of finding-form is from form to state. It is difficult that the hypothesis of initial form should approximate to the result in many cases. 2.the form is unreasonable because the solution of stress is not uniformly distributed and boundary condition is not coincident with the state . 3. The method decreasing the temperature to determine the initial stress is not accurate by itself. Hence ANSYS is not a ideal software of cable-membrane design. Contrast the program in this paper and the software- ANSYS , we can find the program precision is less than the software- ANSYS. But it also satisfy the actual engineering require. Owing to avoiding original coordinate and nonlinear convergence, it can more efficient to calculate, and also suit to the work of initial structure projects.Finally, based on sum up of research work of this paper, the further research of cable-membrane structure is looked forward.