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Finite Element Model Updating Of Continuous Rigid Frame Bridge Based On Static And Dynamic Load Test And Matrix Correction Method

Posted on:2018-10-23Degree:MasterType:Thesis
Country:ChinaCandidate:Z Y YanFull Text:PDF
GTID:2322330542470201Subject:Architecture and civil engineering
Abstract/Summary:PDF Full Text Request
With the development of bridge construction,the old bridges have been replaced by bridges frequently.In order to improve the efficiency of health assessment for old bridges,it has become a hot topic for scholars to rapidly modify the finite element models of bridges.The matrix model updating method can overcome many common problems such as long modification time,complex algorithm and non convergence of calculation results,and it also can meet the requirement of Engineering accuracy.In order to explore the feasibility and reliability of the matrix correction method to quickly correct finite element model of the bridge,this dissertation based on a lot of reading,the consistent mass matrix,mass matrix,stiffness matrix parameters were deduced;Then,by using the ANSYS and the MATLAB,the finite element model of a simply supported beam was modified by matrix correction method,and the accuracy of the method was studied;Finally,an active continuous rigid frame bridge was modified by this method,and the feasibility and reliability of the matrix updating method for the rapid modification of the finite element model were discussed.The main research contents and conclusions are as follows:(1)The 4 order consistent mass matrix,the lumped mass matrix and the stiffness matrix were derived.The 6 order consistent mass matrix and stiffness matrix parameter expressions were exhibited.The difference between the consistent mass matrix and the lumped mass matrix was studied;(2)A finite element model of simply supported beam was established by using ANSYS.The damaged finite element model of simply supported beam was simulated by artificially decreasing its elastic model and moment of inertia,and damaged model was established.The sensitivity of the first order natural frequency of the structure was analyzed by combining the ANSYS and the MATLAB,and the order of correction of stiffness matrix and mass matrix correction was determined.The correction factor of the matrix was selected by enumeration fitting method.The accuracy of model updating was investigated by analyzing the first five order natural frequencies of structures.The MATLAB script program of the intelligent selection correction factor was compiled,and the reliability of the model updating was verified;(3)The static and dynamic test of an active continuous rigid frame bridge wasintroduced.The finite element model of the bridge structure was established.The order of correction of stiffness matrix and the mass matrix was determined by sensitivity analysis;(4)According to the frequency results measured by the bridge dynamic load test,the finite element model of the bridge was modified by combining the ANSYS and the MATLAB.Based on the static load test results of the bridge,the accuracy of the modified bridge model was analyzed by using the MIDAS.The results show that the finite element model updating method was feasible and reliable in the actual bridge engineering,and this dissertation has provided a method for the rapid updating of the finite element model of bridge structure.
Keywords/Search Tags:model updating, matrix correction method, static and dynamic test, sensitivity analysis, matrix modified coefficient
PDF Full Text Request
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