scholarly journals A Multiscale Finite Element Model Validation Method of Composite Cable-Stayed Bridge Based on Structural Health Monitoring System

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Rumian Zhong ◽  
Zhouhong Zong ◽  
Qiqi Liu ◽  
Haifei Zhou

A two-step response surface method for multiscale finite element model (FEM) updating and validation is presented with respect to Guanhe Bridge, a composite cable-stayed bridge in the National Highway number G15, in China. Firstly, the state equations of both multiscale and single-scale FEM are established based on the basic equation in structural dynamic mechanics to update the multiscale coupling parameters and structural parameters. Secondly, based on the measured data from the structural health monitoring (SHM) system, a Monte Carlo simulation is employed to analyze the uncertainty quantification and transmission, where the uncertainties of the multiscale FEM and measured data were considered. The results indicate that the relative errors between the calculated and measured frequencies are less than 2%, and the overlap ratio indexes of each modal frequency are larger than 80% without the average absolute value of relative errors. These demonstrate that the proposed method can be applied to validate the multiscale FEM, and the validated FEM can reflect the current conditions of the real bridge; thus it can be used as the basis for bridge health monitoring, damage prognosis (DP), and safety prognosis (SP).

2020 ◽  
Vol 145 ◽  
pp. 106972 ◽  
Author(s):  
Panagiotis Seventekidis ◽  
Dimitrios Giagopoulos ◽  
Alexandros Arailopoulos ◽  
Olga Markogiannaki

2018 ◽  
Vol 18 (4) ◽  
pp. 1189-1206 ◽  
Author(s):  
Dimitrios Giagopoulos ◽  
Alexandros Arailopoulos ◽  
Vasilis Dertimanis ◽  
Costas Papadimitriou ◽  
Eleni Chatzi ◽  
...  

2020 ◽  
pp. 147592172093951 ◽  
Author(s):  
Zeyu Xiong ◽  
Branko Glisic

Reliable damage detection over large areas of structures can be achieved by spatially quasi-continuous structural health monitoring enabled by two-dimensional sensing sheets. They contain dense arrays of short-gauge sensors, which increases the probability to have sensors in direct contact with damage (e.g. crack opening) and thus identify (i.e. detect, localize, and quantify) it at an early stage. This approach in damage identification is called direct sensing. Although the sensing sheet is a reliable and low-cost technology, the overall structural health monitoring system that is using it might become complex due to large number of sensors. Hence, intentional reduction in number of sensors might be desirable. In addition, malfunction of sensors can occur in real-life settings, which results in unintentional reduction in the number of functioning sensors. In both cases, reduction in the number of (functioning) sensors may lead to lack of performance of sensing sheet. Therefore, it is important to explore the performance of sparse arrays of sensors, in the cases where sensors are not necessarily in direct contact with damage (indirect sensing). The aim of this research is to create a method for optimizing the design of arrays of sensors, that is, to find the smallest number of sensors while maintaining a satisfactory reliability of crack detection and accuracy of damage localization and quantification. To achieve that goal, we first built a phase field finite element model of cracked structure verified by the analytical model to determine the crack existence (detection), and then we used the algorithm of inverse elastostatic problem combined with phase field finite element model to determine the crack length (quantification) and location (localization) by minimizing the difference between the sensor measurements and the phase field finite element model results. In addition, we experimentally validated the method by means of a reduced-scale laboratory test and assessed the accuracy and reliability of indirect sensing.


2017 ◽  
Vol 17 (2) ◽  
pp. 227-239 ◽  
Author(s):  
Rollo Jarvis ◽  
Peter Cawley ◽  
Peter B Nagy

The detection of corrosion on insulated and/or coated pipes remains a challenge. A non-destructive evaluation method has been proposed where a low-frequency AC current is directly injected into the pipe at distant locations, and perturbations in the magnetic field induced by current deflection around defects are measured. Structural health monitoring is made possible by detecting changes in the magnetic field due to defect growth using a permanently installed array of sensitive and inexpensive magnetic sensors. The performance of current deflection structural health monitoring is evaluated using a flexible and efficient framework. Individual sensor performance was first predicted using receiver operating characteristics obtained by evaluating the stability of the magnetic field signal measured outside of a section of coated undamaged riser pipe in an environmental chamber over repeated temperature cycles. A finite element model was then used to predict the magnetic perturbation due to defect growth which allowed the potential array configurations for structural health monitoring to be explored. Results suggest that 90% probability of detection and 0.1% probability of false alarm for [Formula: see text] (wall thickness) diameter, 30% of T depth defects are possible outside of 25- to 50-mm-thick pipe coatings/insulation using 10–50 sensors per metre of pipe and 5–10 A of injected current. The structural health monitoring procedure was then demonstrated experimentally, an electrochemically grown defect being successfully monitored; this experiment also served to validate the three-dimensional finite element model. A very good agreement between the predicted and measured changes in the magnetic field due to the current deflection around the growing defect was obtained.


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