Method for finding feasible prestress of cable-pole structure

Abstract

The invention provides a method for finding feasible prestress of a cable-pole structure. The method comprises the steps that an analysis model including a load F, a prestress initial value P*, a calculation error epsilon n and a displacement calculation error epsilon d is established, a Newton iterative formula is established according to a fuzzy expression between the input value P of the prestress and the output value N of unit internal force and is used for iterative calculation on the prestress P until the error requirement is met; whether the feasible prestress of the cable-pole structure is found out or not and whether reasonable updating needs to be conducted on structure geometry are judged according to the structure self-stress modal number, the internal force of a cable and a pole and the displacement of the structure, during geometry updating, the structure deformation under the prestress P and the load F is directly stacked to an original geometry to be conducted, and the prestress iteration and geometry updating are circularly conducted until all index requirements are met. According to the method, in the process of finding the feasible prestress of the cable-pole structure, reasonable geometry updating can be conducted, and the load possibility of the structure can be taken into consideration.

Description

Technical field [0001] The present invention relates to a calculation method of feasible prestress, specifically a method for finding feasible prestress of cable-strut structure, and its application scope includes cable dome structure, cable truss structure, cable net structure and suspension dome structure and the cable-strut system at the lower part of the string beam structure. Background technique [0002] In the field of large-span spatial structure engineering, cable structures, cable-struts and cable-strut-beam structures have received widespread attention as the roofs of stadiums, convention centers, railway stations, and airport terminals. In 1927, Fuller first proposed the concept of tensegrity structure, and then Snelson built the world's first model of tensegrity structure. On the basis of the tensioned overall structure, Geiger invented the cable dome structure by arranging ring beams around the tensioned overall structure. The cable dome was successively used ...

AI Technical Summary

Problems solved by technology

At present, there are certain studies on the prestressed design of cable-strut structures at home and abroad, but no literatures and patents have been found that can not only consider the load but also rationalize the unreasonable structural geometry and update the prestressed design.

[0003] Researches at home and abroad include the article "Structural Computations with the Singular Value Decomposition of the Equilibrium Matrix" published by Pellegrino et al. in "International Journal of Solids and Structures" in 1993, by performing singular value decomposition on the equilibrium matrix of structural geometry, and obtaining The self-stress mode of the structure, but this method can only be carried out under the premise that the structure geometry is determined and reasonable, and the external load and self-weight of the structure cannot be considered

In 2002, YUAN et al. published the article "Integral feasible pre-stress of cable domes" on "Computers and Structures" based on the symmetry characteristics of the cable dome structure itself, and proposed the concept of the overall feasible pre-stress of the structure, and the traditional singular value decomposition method It has been simplified, but the structural load cannot be considered when using this method to find and design the prestress, and it must be carried out under the premise that the structural geometry is determined and reasonable

Later, in the article "Simple approach for force finding analysis of circular Geiger domes with consideration of self-weight" published by Wang et al. in "Journal of Constructional Steel Research", the self-weight of the structure was converted into the node load and the structure that can be considered was given by the node balance method. The simplified calculation method of self-weight, but this method is only used on Geiger dome and Levy dome with single self-stress mode, and there is no report on the application of this method to other cable dome forms with multiple self-stress modes. This method can also be applied on the basis of definite and reasonable structural geometry, and there is no report on the application of this method to the prestressed design considering any form of load

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