Evaluation of Different Monitoring Techniques During Damage Infliction on Structures

Mechanical Systems and Signal Processing

Kim

O’Brien

et al. 2020

This paper presents a novel bridge condition assessment methodology using direct rotation measurements. Initially, numerical analyses are carried out to develop the theoretical basis of the proposed bridge damage detection methodology. As a result of this study the difference in rotation influence lines obtained for healthy and damaged bridge states is proposed as a damage indicator. The sensitivity of rotation to damage and the effect of sensor locations on sensor sensitivities are investigated. Subsequently, extensive laboratory experiments are conducted on a 5.4 m long simply supported bridge structure in an effort to validate the results from the numerical analyses. The test structure is instrumented with rotation sensors and axle detectors and loaded with a fouraxle moving vehicle. In this study, rotations are measured using high grade uniaxial accelerometers. The procedure of measuring rotations using accelerometers is explained within the scope of this study. To test the robustness of the proposed bridge condition assessment methodology, a wide range of single and multiple damage scenarios is investigated and the results from this study show that the proposed methodology can successfully identify damage on a bridge. For the model considered, damage as low as 7% change in stiffness over an extent of 2.5% bridge span is shown to be detectable.

Section: Overview Of Bridge Damage Detection Methods Using Direct Rotmentioning

confidence: 99%

Bridge damage detection using rotation measurements – Experimental validation

Mechanical Systems and Signal Processing

Kim

O’Brien

et al. 2020

“…damage. Recent studies have developed various rotation-based damage detection techniques for bridge monitoring systems, including visionbased methods and measurement data from inertial sensors [20][21][22][23]. Damage detection techniques are still relatively unproven for monitoring of bridges during scour events and also require an undamaged model of the bridge.…”

Section: Rotation-based Structural Health Monitoringmentioning

confidence: 99%

Tracking bridge tilt behaviour using sensor fusion techniques

Faulkner

Wang

J Civil Struct Health Monit

2020

The resilience of the built environment to extreme weather events is fundamental for the day-today operation of our transport network, with scour representing one of the biggest threats to bridges built over flowing water. Condition monitoring of the bridge using a structural health monitoring system enhances resilience by reducing the time needed to return the bridge to normal use by providing timely information on structural condition and safety. The work presented in this report discusses use of rotational measurements in structural health monitoring. Traditionally tiltmeters (which can be a form of DC accelerometer) are used to measure rotation but are known to be affected by dynamic movements, while gyroscopes react quickly to dynamic motion but drift over time. This review will introduce gyroscopes as a complementary sensor for accelerometer rotational measurements and use sensor fusion techniques to combine the measurements from both sensors to get an optimised rotational result. This method was trialled on a laboratory scaled model, before the system was installed on an in-service single-span skewed railway bridge. The rotational measurements were compared against rotation measurements obtained using a vision-based measurement system to confirm the validity of the results. An introduction to gyroscopes, field test measurement results with the sensors and their correlation with the vision-based measurement results are presented in this article.

“…Inclinometers have also been used to calculate the deformed shape of bridge deck structures (Burdet & Zanella, 2000;He, Yang, & Zhao, 2014;Helmi, Taylor, Zarafshan, & Ansari, 2015;Hou, Yang, & Huang, 2005;LLoret, Inaudi, & Vurpillot, 1998;O'Leary & Harker, 2012;Perregaux, Vurpillot, Inaudi, & Burdet, 1998;Robert-Nicoud, Raphael, Burdet, & Smith, 2005;Sousa, Cavadas, Henriques, Bento, & Figueiras, 2013;Vurpillot, Krueger, Benouaich, Clément, & Inaudi, 1998), the advantage being that unlike any other direct methods of measuring bridge deflections, inclinometers do not require a reference point. Alten, Ralbovsky, Vorwagner, Toplitzer, and Wittmann (2017) evaluated different monitoring techniques through a progressive damage case study conducted on a posttensioned reinforced concrete bridge over a 12 week period. The test bridge was instrumented with 23 sensors: 6 accelerometers, 2 biaxial inclinometers (at support locations) and 15 fibre-optic strain gauges.…”

Section: Rotation Measurement In Bridgesmentioning

confidence: 99%

Identifying damage in a bridge by analysing rotation response to a moving load

Hester

Structure and Infrastructure Engineering

O’Brien

et al. 2019

This paper proposes a bridge damage detection method using direct rotation measurements. Initially, numerical analyses are carried out on a 1-D simply supported beam model loaded with a single moving point load to investigate the sensitivity of rotation as a main parameter for damage identification. As a result of this study, the difference in rotation measurements due to a single moving point load obtained for healthy and damaged states is proposed as a damage indicator. A relatively simple laboratory experiment is conducted on a 3 m long simply supported beam structure to validate the results obtained from the numerical analysis. The case of multi-axle vehicles is investigated through numerical analyses of a 1-D bridge model and a theoretical basis for damage detection is presented. Finally, a sophisticated 3-D dynamic Finite Element model of a 20 m long simply supported bridge structure is developed by an independent team of researchers and used to test the robustness of the proposed damage detection methodology in a series of blind tests. Rotations from an extensive range of damage scenarios were provided to the main team who applied their methods without prior knowledge of the extent or location of the damage. Results from the blind test simulations demonstrate that the proposed methodology provides a reasonable indication of the bridge condition for all test scenarios.