Beam bridge damage detection method based on deflection influence line of elastically restricted supporting beam

Abstract

The invention discloses a beam bridge damage detection method based on a deflection influence line of an elastically restricted supporting beam. The method comprises the following steps: building a model, analyzing a deflection influence line and concretely implementing damage identification. Specific to defects of a fabricated railway bridge model, the method disclosed by the invention builds anelastically supported boundary beam model with a rotation restraint by combining uncertainty of elastic modulus and sectional dimension of a main beam initial material, so as to simulate a main beam structure of a fabricated railway bridge; by deducing an analytic expression of the deflection influence line of the model and combining finite element example analysis, the deflection influence line method is applied to damage identification study on a fabricated beam structure, influence of a position of a measuring point of the influence line, location and level of a local damage as well as testnoise on an identification result is studied, and a method reference and a study thinking are provided for damage identification and service performance evaluation on an existing fabricated railway bridge structure; and the method disclosed by the invention can be used for identifying occurrence of a local damage of an elastically supported beam with a rotation restraint and accurately determining location of the damage and realizes precise damage quantification.

Description

technical field [0001] The invention belongs to the field of bridge damage detection, in particular to a beam bridge damage detection method based on deflection influence lines of elastically constrained supporting beams. Background technique [0002] In recent years, prefabricated railway bridges have been widely used because they are easy to pour and install. There are certain differences between the actual support conditions and the theoretical boundaries. It is difficult for finite element software to simulate the interface at the prefabricated assembly nodes, which introduces a big problem for theoretical calculation and actual engineering. deviation. Uncertainty factors such as the ambiguity of construction materials, the randomness of construction errors, and the discreteness of cross-sectional dimensions cannot be ignored, resulting in unsatisfactory initial models and boundary conditions of railway bridges, and it is difficult to achieve ideal hinged and rigid joint...

AI Technical Summary

Problems solved by technology

The current method has not considered the influence of the vertical elastic constraints at the beam end and the uncertain factors of the initial structural model, and the related research has not considered the influence of the non-ideal support boundary of the assembled beam model, which affects the accuracy of bridge damage detection

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