Determination method of initial completion initial cable force of cable-stayed bridge

Abstract

The invention relates to a determination method based on an ANSYS second development platform of the initial completion initial cable force of a cable-stayed bridge. The method uses the design cable force as the target value, considers the geometric non-linear effect and performs iteration for solving and correcting the cable initial strain under the action of dead load. The method comprises the following specific steps: any group of cable forces is assumed to be added on the stay cable in the mode of initial strain, dead load is added to calculate, the *do-loop command language is used to extract the calculated cable force of the stay cable and check whether the error between the cable force and the target completion cable force is within an available limit; if the error is large, the indifference method is used to correct the stay cable initial strain, then the error is calculated again until the error is within the available limit; and the initial completion initial cable force can be obtained by multiplying the last calculated group of stay cable initial strains by the elastic modulus of the stay cable which is corrected by considering the vertical effect. By using the method, the solving time of the completion initial cable force of the cable-stayed bridge can be reduced and the precision can be increased, thus the method has large practical engineering application value.

Description

technical field [0001] The invention belongs to the field of bridge and culvert engineering in the transportation industry, and in particular relates to a method for determining the initial cable force of a cable-stayed bridge based on the ANSYS platform. Background technique [0002] The long-span cable-stayed bridge is a high-order hyperstatically indeterminate system with significant structural geometric nonlinear effects and a large number of cables. In the analysis of its ultimate bearing capacity, it is first necessary to provide a set of initial cable forces so that the cable forces are consistent with the design or measured cable forces under the bridge’s dead load, but the whole process of determining this set of initial cable forces is very cumbersome , sometimes even fail to converge. At present, the existing life-death element method uses the life-death characteristics of the element to directly apply a pair of concentrated forces to the nodes at both ends of th...

AI Technical Summary

Problems solved by technology

In the analysis of its ultimate bearing capacity, it is first necessary to provide a set of initial cable forces so that the cable forces are consistent with the design or measured cable forces under the bridge’s dead load, but the whole process of determining this set of initial cable forces is very cumbersome , sometimes even fail to converge

At present, the existing life-death element method uses the life-death characteristics of the element to directly apply a pair of concentrated forces to the nodes at both ends of the cable, which cannot consider the displacement of the nodes at both ends of the cable caused by the geometric nonlinearity of the structure. The sag effect of the cables leads to a large error between the calculated cable force of the bridge and the design cable force

The method of directly applying the cable force by setting the initial strain of the cable or the temperature load according to the design cable force also has certain limitations, because the cable force is applied on the basis of the undeformed structure, and the structural deformation under the constant load will inevitably lead to cable force changes

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