scholarly journals Dynamic Parameter Identification of a Long-Span Arch Bridge Based on GNSS-RTK Combined with CEEMDAN-WP Analysis

2019 ◽  
Vol 9 (7) ◽  
pp. 1301
Author(s):  
Chunbao Xiong ◽  
Lina Yu ◽  
Yanbo Niu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Parameter Identification ◽  
Noise Reduction ◽  
Element Model ◽  
Modal Parameters ◽  
Arch Bridge ◽  
Long Span Bridges ◽  
Long Span ◽  
Ambient Excitation

Under the action of wind, traffic, and other influences, long-span bridges are prone to large deformation, resulting in instability and even destruction. To investigate the dynamic characteristics of a long-span concrete-filled steel tubular arch bridge, we chose a global navigation satellite systems-real-time kinematic (GNSS-RTK) to monitor its vibration responses under ambient excitation. A novel approach, the use of complete ensemble empirical mode decomposition with adaptive noise combined with wavelet packet (CEEMDAN-WP) is proposed in this study to increase the accuracy of the signal collected by GNSS-RTK. Fast Fourier transform (FFT) and random decrement technique (RDT) were adopted to calculate structural modal parameters. To verify the combined denoising and modal parameter identification methods proposed in this paper, we established the structural finite element model (FEM) for comparison. Through simulation and comparison, we were able to draw the following conclusions. (1) GNSS-RTK can be used to monitor the dynamic response of long-span bridges under ambient excitation; (2) the CEEMDAN-WP is an efficient method used for the noise reduction of GNSS-RTK signals; (3) after signal filtering and noise reduction, structural modal parameters are successfully derived through RDT and illustrated graphically; and (4) the first-order natural frequency identified by field measurement is slightly higher than the FEM in this work, which may have been caused by bridge damage or the inadequate accuracy of the finite element model.

scholarly journals Wind-driven damage localization on a suspension bridge

2016 ◽  
Vol 11 (1) ◽  
pp. 11-21 ◽  
Author(s):  
Marco Domaneschi ◽  
Maria Pina Limongelli ◽  
Luca Martinelli
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Damage Identification ◽  
Structural Response ◽  
Suspension Bridge ◽  
Element Model ◽  
Damage Localization ◽  
Damage Scenarios ◽  
Long Span Bridges ◽  
Long Span

The paper focuses on extending a recently proposed damage localization method, previously devised for structures subjected to a known input, to ambient vibrations induced by an unknown wind excitation. Wind induced vibrations in long-span bridges can be recorded without closing the infrastructure to traffic, providing useful data for health monitoring purposes. One major problem in damage identification of large civil structures is the scarce data recorded on damaged real structures. A detailed finite element model, able to correctly and reliably reproduce the real structure behavior under ambient excitation can be an invaluable tool, enabling the simulation of several different damage scenarios to test the performance of any monitoring system. In this work a calibrated finite element model of an existing long-span suspension bridge is used to simulate the structural response to wind actions. Several damage scenarios are simulated with different location and severity of damage to check the sensitivity of the adopted identification method. The sensitivity to the length and noise disturbances of recorded data are also investigated.

PARAMETER IDENTIFICATION BY UPDATING THE FINITE ELEMENT MODEL FOR A FLEXIBLE WING

2021 ◽  
Author(s):  
Thiago Rosado de Paula ◽  
Vítor Fernandes ◽  
Luiz Carlos Sandoval Góes ◽  
David Fernando Castillo Zuñiga ◽  
Alain Souza ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Parameter Identification ◽  
Element Model ◽  
Flexible Wing ◽  
The Finite Element Model

Research on the Shear Nails on the Arch Foot of an Oblique Cross Steel Box Arch Bridge

2013 ◽  
Vol 663 ◽  
pp. 49-54
Author(s):  
Xin Huang ◽  
Z.Z. Bai ◽  
De Wei Chen
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Finite Element Model ◽  
Mechanical Performance ◽  
Maximum Shear Stress ◽  
Element Model ◽  
Bottom Up ◽  
Arch Bridge ◽  
Distribution Rules

In order to find the distribution rules on the shear nails on the steel-concrete composite segment of arch foot of an oblique cross steel box arch bridge, it established a space finite element model through the engineering of Wenzhou Weiwulu oblique cross steel box arch bridge, analyzing the maximum shear stress of the shear nails under normal using stage. The result shows that the welding nails in different position have a great difference in their shear stress. The welding nails which welded in a place that has a greater stiffness bear a bigger shear stress. So their mechanical performance of steel-concrete segment is better. In addition, the maximum shear stress becomes bigger from the bottom up to the top of the steel box.

A Method to Determine the Boundary Conditions of the Finite Element Model of a Slender Beam Using Measured Modal Parameters

1996 ◽  
Vol 118 (3) ◽  
pp. 474-478 ◽  
Author(s):  
Wang Fengquan ◽  
Chen Shiyu
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Finite Element Model ◽  
Interpolation Method ◽  
Element Model ◽  
Accurate Method ◽  
Modal Parameters ◽  
Computation Method ◽  
Modal Parameter ◽  
The Finite Element Model

In this paper, a method used to determine the boundary conditions of the Finite Element Model of a slender beam with measured structure modal parameters is presented. On deriving the method, the finite element model theory for dynamic calculating is used. Combined with the modal parameters from experiment, an FEM-modal parameter equation to determine the boundary conditions is put forward. For solving the equation, three methods are given. The first is the accurate method. The second is the full mode computation method by means of generalized inverse matrix. The third is the interpolation method of frequency. A numerical simulation with computer is given and the results of calculation fully verify the effectiveness of the method offered and also verify that the accuracy of the method is satisfying. Finally, an applied example is given and the results of calculation fully verify the effectiveness of the method offered.

Mechanical Performance and Spatial Stability under Live Load and Wind on Tied-Arch Bridge

2014 ◽  
Vol 501-504 ◽  
pp. 1238-1242
Author(s):  
Li Wang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Safety Factor ◽  
Mechanical Performance ◽  
Influence Factors ◽  
Element Model ◽  
Structural Defects ◽  
Positive Contribution ◽  
Arch Bridge ◽  
Tied Arch Bridge

Finite element model of the background tied-arch bridge was established and analyzed. Meanwhile, mechanical performance and stability of it under several kinds of simulate structural defects and damages were studied. Some typical damage and influence factors were presented in the beginning. Then, based on the finite element model, the distribution of suspender force corresponding to the simulated defects and failure was calculated respectively. At last, the first class stability safety factor under the combination load was calculated as well as the second class nonlinear stability safety factor under structural arch rib defect. Results of above calculation imply that, suspender forces gained a stronger sensitivity to vertical defect than to transverse defect. While, short suspenders were believed to be more sensitive to lineation defect than long ones according to calculation results. Additionally, secondary inner force of short suspenders was much more intensive than in long ones. The result also tells that lateral wind did bad to stability. Lift wind, contrarily, made a little positive contribution to structures in-plane stability. Simulated structural defects were supposed to aggravate the second class stability safety factor under geometric nonlinear condition.

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