Method for calculating time-varying bending moment and bending deformation of bridge under action of moving vehicle load

Abstract

The invention discloses a method for calculating a time-varying bending moment and bending deformation of a bridge under the action of a moving vehicle load, and belongs to methods for calculating bending moments and deflection of bridges. The method comprises the steps of (1) listing out a bending moment equation of the bridge under the action of the moving vehicle load based on a singularity generalized function; (2) substituting a bending moment into a deflection curve differential equation, and performing integration on the differential equation twice based on a singularity generalized function integration method to obtain a deflection curve equation; (3) complementing equations according to constraint conditions to solve unknown variables in the deflection curve equation, namely, listing out a deflection equation of the bridge at a support and a force boundary equation of a rightmost support; (4) solving the complementary equations by virtue of Mathcad to obtain constraint reactions and integral constants changed with vehicle load speeds and time; (5) substituting the obtained constraint reactions and integral constants in the Mathcad into the bending moment equation and the deflection curve equation to obtain corresponding bending moment function and deflection function; and (6) enabling the method to be suitable for deformation calculation of the bridge under the condition of different spans, different vehicle load quantities, different vehicle load moving speeds and different vehicle moving directions.

Description

technical field [0001] The invention relates to a method for calculating variable bending moment and bending deformation of a bridge, in particular to a method for calculating time-varying bending moment and bending deformation of a bridge under the action of a mobile vehicle. Background technique [0002] The deformation and vibration of bridges under the action of vehicles are important factors affecting the use and safety of bridges, especially the deformation and vibration of long-span bridges under moving loads are of particular concern to the engineering community. [0003] The bending deformation of the bridge is affected by the number of bridge supports, the number of vehicles passing the bridge, and the moving direction of the vehicles. It is more convenient to solve the bending moment and deformation of a single-span beam under concentrated load in classical material mechanics, and the integral method is generally used. The multi-span bridge is a statically indete...

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Problems solved by technology

[0004] The purpose of this invention is to provide a kind of method that calculates time-varying bending moment and bending deformation of the bridge under the action of moving vehicle, solve the calculation method of existing bridge bending deformation in the multi-span bridge under the action of moving load, according to the existing classical method to solve complex , even problems that cannot be solved

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