Damage Identification Study Of CFST Tied Arch Bridge With Composite Hanger

Concrete-filled steel tubular(CFST) arch bridges are developing rapidly in China. But as time goes on, the CFST arch bridge diseases occur every now and then under the action of multiple factors. As a result, the damage identification of CFST arch bridges has become an important problem to engineering technicians. Aimed at CFST tied arch bridges with composite hanger, based on the basic theory of bridge structural dynamics and BP neural network, with engineering examples, the dynamic signatures of injury and intact structure, such as frequency, mode of vibration, curvature were calculated and analyzed. BP neural networks were established to identify the damage of CFST tied arch bridges with composite hanger. The main contents are as follows:(1) Referring to domestic and foreign articles focused on bridge damage identification, the existing problems in bridge damage identification were analyzed. The main contents of study were determined. And the adopted research approaches and detailed flow diagrams were explicated.(2) Aiming at dynamic signatures applied for bridge damage identification in common use at home and abroad, based on the bridge damage identification calculation theories and analysis methods of dynamic signatures, every dynamic signature’s and applicability were determined. Combining with inductive analysis of existing research results, dynamic signatures applied to damage identification of CFST tied arch bridges with composite hanger were recommended. Based on BP neural network theory, the execution steps of bridge damage identification based on BP neural network were explicated.(3) With the aid of the finite element software, the numerical model of engineering examples was established. The uncertain damages of arch rib, prestressed tie bar and composite hanger were simulated and calculated. Based on the calculation and analysis of construction examples, the frequency, mode of vibration and curvature were applied to identify the damage of CFST tied arch bridge with composite hanger. Every dynamic signature’s application to the uncertain damage of bridge structure was discussed.(4) With engineering examples, based on BP neural network theory, regarding dynamic signatures of CFST tied arch bridges with composite hanger with uncertain damage as original data, BP neural networks were established using MATLAB. According to the damage identification of sub-components, cable hanger and steel pipe hanger, the damage identification of composite hanger was realized. The reliability of the method was proved by engineering examples.