Suspension bridge space cable shape finding method based on finite elements

Abstract

The invention belongs to the technical field of bridge engineering. The invention provides a suspension bridge space cable shape finding method based on finite elements. The suspension bridge space cable shape finding method comprises the following steps: 1) establishing an initial finite element model containing a main cable and a suspender, a lifting point of the lifting rod on the main beam only restrains longitudinal and vertical degrees of freedom, and releasing lateral constraints, applying a suspender transverse tensioning force design value, so as to ensure that the tension force of the suspender in each step of iterative calculation is always a design required value; 2) updating the finite element model after determining the line shape and the internal force initial value of the space cable by applying a small elastic modulus technology; (3) updating the cable line shape and the internal force through nested loop expansion iterative computation and internal loop, ensuring thatthe internal force of a convergence result suspender is a design requirement value, correcting a main cable node coordinate through external loop, ensuring that a convergence result main cable control point coordinate is a design value, performing internal and external loop alternate iteration until a convergence requirement is met, and (4) outputting a result. The suspension bridge space cable shape finding method is simple to operate, stable in convergence, high in precision, high in speed, high in universality and convenient for engineering application and popularization.

Description

technical field [0001] The invention belongs to the technical field of bridge engineering and relates to a form-finding method for cables of a suspension bridge, in particular to a form-finding method for space cables of a suspension bridge based on finite elements. Background technique [0002] When engineers design suspension bridges, in order to improve their mechanical properties and improve the aesthetic effect, they usually use cables with space cable planes. cable to improve the lateral stiffness and torsional stiffness of the structure, Shandong Yimeng Mountain Pedestrian Suspension Bridge (span 420m), Swiss Charles-Kuna Pedestrian Cable Truss Bridge (span 494m) and the Yellow River Wanjiazhai Water Conservancy Project Pedestrian Cable Bridge (span 500m), etc. Space wind cables are used to improve the wind resistance performance of the structure. Among them, the wind cable suspenders of the pedestrian cable bridge of the Wanjiazhai Water Conservancy Project on the Ye...

AI Technical Summary

Problems solved by technology

[0005] (1) This method requires programming to solve complex nonlinear equations, which is not convenient for engineering personnel to apply and promote;

[0006] (2) The convergence stability of this method is poor, and it is necessary to introduce a suitable relaxation factor or an initial value of human intervention, which is difficult for designers who lack engineering experience

[0007] (3) This method can be used for form-finding of spatial cables for parallel suspender systems, but it cannot be used to solve more complex spatial cables with suspenders inclined along the bridge direction

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