Papers by Author: Xu Xie

Abstract: For the common diseases of the hinge joint, a new structure named thin-film layer is presented to simulate its function in finite element model. Through the field test of an on-built bridge, real measured results are used to determine the parameters of the layer in the model. The model result shows that the deformations of the hinge joint include vertical shear dislocation and transverse bending deformation, which may lead to different kinds of diseases of the structure. A certain amount of reinforcements with reasonable configuration focusing on intensifying the whole structure is preferred.

Abstract: For short hangers, the influence of flexural rigidities and boundary conditions on tension measuring cannot be neglected. But there has no effective method to precisely calculate hanger tension considering the two parameters. This paper proposes the Added Mass Method (AMM) to simultaneously identify the tension, flexural rigidity and boundary condition of short hangers. In this method, the effect of mass distribution of structure on natural frequencies has been studied to add extra calculation conditions for establishing the eigenvalue equation set. The method of Genetic Algorithm (GA) with adaptive crossover and mutation rate is used to solve the equation set quickly. The results provides that the AMM is a high-accurate field testing technology in tension measurement for short hanger of arch bridge.

Abstract: The damping makeup of large span cable-stayed bridges is complicated. The damping matrices of such structures cannot be easily accurately determined. On assumption of the damping coefficients of substructures in cable-stayed bridge (such as girder, tower, cable and support et al) are constants, a method to estimate the damping coefficients and damping matrices of such structures is presented. The method is based on several known modal damping ratios and the calculation of complex eigenvalue and eigenvector utilizing the state-space methodology. Numerical simulation was carried out by the example of Tatara Bridge. Through comparison between the calculated damping ratios utilizing the approximated damping matrices and the field test data, the method is proved valid.