The Equivalent Model Of Large-scale Steel Fold-shaped Suspension Bridge Based On Experimental Modal Analysis

In recent years, due to the rapid development of steel processing technology and construction technology and construction technology of prestressed concrete, Span CFST Tied Arch and steel suspension bridge in the country has been developing rapidly. For the new bridge, the bridge through field static and dynamic load tests can assess the quality of its design and construction, to determine the reliability engineering, test and improve bridge design theory. The bridge structure vibration characteristics of the test is one of the core content of the test bridge. The purpose of the experimental modal analysis of the existing structure of the system is to identify and evaluate the dynamic characteristics of the structure of the system to find out the problems and provide the basis for the analysis of experimental model validation and modification of structural dynamics. Therefore, the existing power structure field test is very necessary.Because the bridge is a large structure and the diversity and complexity of the cross-sectional structure of the bridge deck, using solid elements in addition to more difficult than modeling, modeling and computational workload is very large, the equivalent model calculations for computational analysis fast computation and improve the efficiency of the bridge design characteristics for all have a very important reference. With the development of the bridge model and related analysis software equivalent model and the actual situation analysis will be closer to the bridge plate, so the equivalent analysis model for guidance bridge construction will be increasingly important.In this paper, the zigzag bridge atrium inside Bengbu City Museum as the research object, discussion on the deck equivalent model analysis. This is diffcult to model solid element,the workload of modeling and computational is very large, using the equivalent model for rapid calculation of bridge characteristics and improving design efficiency is very important to have a reference value. Consider using equivalent principle, bridge deck is equivalent to the thickness of bridge deck, the width of equivalent bridge deck as the same as the original structure. In order to ensure the theoretical dynamic properties is consistent, bending stiffness, moment of inertia, the line density of equivalent bridge deck should be consistent with the original structure, calculation formula of equivalent cross-section the size of each part parameters by theoretical analysis. Therefore, using finite element analysis software ANS YS to build the simulation model, dividing unit, through static analysis and dynamic characteristics of the original structure and the equivalent structure, the two results are compared and obtained the pros and cons of equivalent analysis. The results show that:the equivalent method is put forward can reflect the actual state of the original structure. The equivalent parameters are real and reliable, equivalent model can reflect the situation of real model.