Numerical Analysis of Bridges with Functional Bearing System Using Vector Form Intrinsic Finite Element
Date Issued
2014
Date
2014
Author(s)
Huang, Wen-Chuan
Abstract
A functional bearing model (FBM) of the bridge is proposed in this research and is applied to Vector Form Intrinsic Finite Element (VFIFE) software to analyze the bridge under seismic loading. Functional bearing system employs displacement limit device to restrict the bridge’s horizontal displacement and dissipate seismic energy through the frictional sliding mechanism. To avoid bridge-falling, the gap between the bridge and bridge-collapse prevention devices is very important. However, in the past research analysis, it’s hard to obtain the bearing’s sliding displacement through the traditional simulation method about rubber bearing. In addition, the displacement obtained by the traditional method includes the residual plastic displacement, which is undesirable in the analysis. Due to the difficulty mentioned above, this research proposes a new simulation method for rubber bearing, called functional bearing model (FBM). It can separate the deformation of bearing into rubber shear deformation and frictional sliding displacement. Therefore, the amount of the gap between the bridge and bridge-collapse prevention devices can be determined clearly.
Structural analysis program SAP2000 is used to build a bridge model. Comparisons between the numerical model and three test results including the frictional coefficient test and shaking table tests are discussed. The comparison results showed that the proposed method is feasible in both static and dynamic analysis. However, neither the influence of the sliding velocity on the friction coefficient nor the geometric nonlinearity can be considered by SAP2000. As a consequence, the prediction of the maximum response doesn’t agree with the experiment result. Also, the non-linear large deformation behavior is not considered, so the bridge-falling or pounding behavior cannot be simulated. In order to obtain the analytical results about bridge-falling mechanism, FBM was applied to VFIFE method. Several examples were built in VFIFE to verify the accuracy of basic element, the non-linear large deformation function and the element fracture function at first. Then manifest the feasibility of VFIFE through comparing the test results and the analytical results of the shaking table test. Finally, the bridge-falling analytical results show that the VFIFE can predict the bridge-falling phenomenon which is due to excessive friction displacement of bearings.
Structural analysis program SAP2000 is used to build a bridge model. Comparisons between the numerical model and three test results including the frictional coefficient test and shaking table tests are discussed. The comparison results showed that the proposed method is feasible in both static and dynamic analysis. However, neither the influence of the sliding velocity on the friction coefficient nor the geometric nonlinearity can be considered by SAP2000. As a consequence, the prediction of the maximum response doesn’t agree with the experiment result. Also, the non-linear large deformation behavior is not considered, so the bridge-falling or pounding behavior cannot be simulated. In order to obtain the analytical results about bridge-falling mechanism, FBM was applied to VFIFE method. Several examples were built in VFIFE to verify the accuracy of basic element, the non-linear large deformation function and the element fracture function at first. Then manifest the feasibility of VFIFE through comparing the test results and the analytical results of the shaking table test. Finally, the bridge-falling analytical results show that the VFIFE can predict the bridge-falling phenomenon which is due to excessive friction displacement of bearings.
Subjects
功能性支承
橡膠支承墊
支承墊滑動
向量式有限元素法
Type
thesis
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