scholarly journals Structural Health Monitoring of Concrete Bridges in Guilan Province Based on a Visual Inspection Method

2013 ◽  
Vol 9 (4) ◽  
pp. 269-285
Author(s):  
Mehdi Mohammadpour Lima ◽  
Dane Miller ◽  
Jeung-Hwan Doh
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Visual Inspection ◽  
Concrete Bridges ◽  
Inspection Method ◽  
Structural Health ◽  
Guilan Province

Structural health monitoring–based methodologies for managing uncertainty in aircraft structural life assessment

2014 ◽  
Vol 13 (6) ◽  
pp. 621-628 ◽  
Author(s):  
Ray Bond ◽  
Sara Underwood ◽  
Douglas E Adams ◽  
Joshua J Cummins
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Life Assessment ◽  
Surface Velocity ◽  
Identification System ◽  
Laser Vibrometer ◽  
Aircraft Maintenance ◽  
Labor Costs ◽  
Inspection Method ◽  
Structural Health

Aircraft maintenance approaches that rely on only scheduled inspections have an intrinsic amount of uncertainty and risk because intervals do not reflect the loading and damage history of individual aircraft. This risk is more pronounced in composite aircraft, because damage is often not visually apparent. This work presents two case studies of complementary structural health monitoring methods that are designed to reduce the risk in aircraft maintenance, as well as the cost of frequent, lengthy inspections. The first is an impact identification system which is capable of locating impacts to a full-scale fuselage using only three sensors. This impact identification method is able to quantify the severity of impacts, allowing maintenance personnel to focus inspections on areas that have sustained frequent and/or high-amplitude impacts. Using this method, over 97% of impacts to a heavy-lift helicopter fuselage are located within 9 in of the true impact location. The second case study details the development of a noncontact wide-area inspection method, which has the potential to reduce inspection times and uncertainty as compared to labor-intensive inspection methods such as coin tap testing. This inspection method exploits the nonlinear forced vibration characteristics of damaged areas through surface velocity measurements acquired by a scanning laser vibrometer. By comparing the structure’s response to forcing functions of differing magnitudes, the local nonlinear characteristics of damage are identified. This automated inspection method is shown to be effective in locating subsurface damage in composite helicopter panels and has the potential to reduce both labor costs and damage detection uncertainty.

An Improved Design Based on Smart Film for Monitoring Crack Width of Concrete Bridges

2011 ◽  
Vol 308-310 ◽  
pp. 2478-2481
Author(s):  
Xing Xing Li ◽  
Ben Niu Zhang ◽  
Zhi Xiang Zhou ◽  
Lian Tang
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Crack Width ◽  
Large Scale ◽  
Concrete Bridges ◽  
Challenging Problem ◽  
Structural Health ◽  
Crack Monitoring ◽  
Improved Design

Structural health monitoring is a promising way for evaluating the integrity and safety of large-scale bridges, and crack monitoring is thought to be a challenging problem in this field. An improved design based on smart film for monitoring crack width of concrete bridges is proposed in this paper. Experiments are also implemented to verify the effectiveness of this design.

Wireless Structural Health Monitoring Using MEMS

2005 ◽  
Vol 293-294 ◽  
pp. 625-634 ◽  
Author(s):  
Markus Krüger ◽  
Christian U. Grosse ◽  
Pedro José Marrón
Keyword(s):  
Structural Health Monitoring ◽  
Monitoring System ◽  
Health Monitoring ◽  
Visual Inspection ◽  
Microelectromechanical Systems ◽  
Life Time ◽  
Building Structures ◽  
Wireless Monitoring ◽  
Structural Health ◽  
Reliability And Robustness

So far, the inspection of building structures and especially of bridges is mainly done visually. Therefore, the condition of the structure is examined from the surface and the interpretation and assessment is based on the experience of the expert. However, the main purpose of monitoring civil structures is not to substitute visual inspection. Continuous structural health monitoring should provide data from the inside of a structure to better understand its structural performance and to predict its durability and remaining life time. Monitoring should render objective data and observable alterations in the structure continuously, which cannot be done by visual inspection. More detailed information is needed with respect to different exposure due to dynamic and static loads and also temperature and moisture. Today mainly wired monitoring systems are used to monitor structures, which are relatively expensive and time consuming to install. In this paper the basic principle of a wireless monitoring system equipped with MEMS sensors is presented, which can be easily installed at different structures. Microelectromechanical systems (MEMS) are small integrated devices or systems that combine electrical and mechanical components. A wireless monitoring sensor network equipped with such MEMS could be produced with a very low budget and becomes very efficient. This permits a wide area of applications not only in civil engineering. With respect to different applications relevant properties of a wireless monitoring system are described. In detail network configuration, power consumption, data acquisition and data aggregation, signal analysis and data reduction as well as reliability and robustness are discussed.

A Simplified Methodology for Condition Assessment of Bridge Bearings Using Vibration Based Structural Health Monitoring Techniques

2021 ◽  
pp. 2150133
Author(s):  
Babar Nasim Khan Raja ◽  
Saeed Miramini ◽  
Colin Duffield ◽  
Shilun Chen ◽  
Lihai Zhang
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Structural Condition ◽  
Condition Assessment ◽  
Concrete Bridges ◽  
Traffic Loading ◽  
Structural Health ◽  
Vibration Data ◽  
Bridge Bearing ◽  
Bridge Bearings

The mechanical properties of bridge bearings gradually deteriorate over time resulting from daily traffic loading and harsh environmental conditions. However, structural health monitoring of in-service bridge bearings is rather challenging. This study presents a bridge bearing condition assessment framework which integrates the vibration data from a non-contact interferometric radar (i.e. IBIS-S) and a simplified analytical model. Using two existing concrete bridges in Australia as a case study, it demonstrates that the developed framework has the capability of detecting the structural condition of the bridge bearings in real-time. In addition, the results from a series of parametric studies show that the effectiveness of the developed framework is largely determined by the stiffness ratio between bridge bearing and girder ([Formula: see text], i.e. the structural condition of the bearings can only be effectively captured when the value of [Formula: see text] ranges from 1/100 and 100.

scholarly journals Quasi-Active Thermography for Structural Health Assessment of Large Geomembranes

2021 ◽  
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Treatment Plant ◽  
Intensity Variation ◽  
Thermal Stimulus ◽  
Image Processing Algorithm ◽  
Inspection Method ◽  
Thermal Transients ◽  
Structural Health ◽  
Active Thermography

Abstract. High density polyethylene (HDPE) geomembranes (approximately 8 hectares each) are employed as floating covers at the wastewater treatment plant of Melbourne Water in Werribee, Australia. The anaerobic lagoons at the plant rely on these HDPE geomembrane floating covers to capture both the biogas and odours. Given the nature of the plant and the harsh environmental conditions, a non-contact inspection method that can cover a vast expanse is the preferred approach for the structural health monitoring and assessment of the cover. This paper presents an exploratory investigation on the use of a quasi-active thermography technique to detect the presence of artificially induced part-through defects on a HDPE geomembrane specimen. The proposed method utilises a naturally occurring heat source (solar radiation) as the thermal stimulus. An infrared thermal camera and a pyranometer were used to record the thermal responses of the HDPE material as a result of solar intensity variation. The viability of using periodic cloud cover transients to drive this inspection technique is reported. In addition, an image processing algorithm is formulated based on the relative summation of the transient events to enhance the identification of the defects. The findings show that the observed thermal transients can be used to define the presence of defects both when the underside of the material is in contact with water or with air, and thereby provides a promising approach for the structural health monitoring of these high-value assets.

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