Fibre Optic Methods for Structural Health Monitoring. Branko Glisic and Daniele Inaudi, John Wiley & Sons, Chichester, 2007. No. of pages: 262. ISBN 978-0470-06142-8

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Tension estimates in cable stayed bridges

A benchmark problem on an existing cable-stayed bridge was recently proposed. Recorded signals are available for standard working conditions and for special events (typhoons!). In this contribution, the authors report their attempt to detect significant variations in the cable tension during these extreme events

validation of a data fusion based solution in view of the real time monitoring of cable stayed bridges

Abstract A precise assessment of the displacements induced by external actions on cables-stayed bridges may be currently challenging and costly when conventional structural health monitoring (SHM) solutions are applied. In order to bypass the drawbacks of wired solutions and the use of expensive equipment, a novel approach is proposed. A Kalman filter-based data fusion of multiple responses is adopted. A GPS receiver and a three-axial accelerometer are used as sensors. The GPS accuracy is enhanced exploiting the satellite corrections provided by a single reference station. The proposed system is validated in situ on the "Tesa" timber footbridge

LOCAL POSITIONING SYSTEMS VERSUS STRUCTURAL MONITORING: A REVIEW

SUMMARY Structural monitoring and structural health monitoring could take advantage from different devices to record the static or dynamic response of a structure. A positioning system provides displacement information on the location of moving objects, which is assumed to be the basic support to calibrate any structural mechanics model. The global positioning system could provide satisfactory accuracy in absolute displacement measurements. But the requirements of an open area position for the antennas and a roofed room for its data storage and power supply limit its flexibility and its applications. Several efforts are done to extend its field of application. The alternative is local positioning system. Non-contact sensors can be easily installed on existing infrastructure in different locations without changing their properties: several technological approaches have been exploited: laser-based, radar-based, vision-based, etc. In this paper, a number of existing options, together with their performances, are reviewed. Copyright © 2014 John Wiley & Sons, Ltd

Framing a satellite based asset tracking (SPARTACUS) within smart city technology

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SMA in mitigation of extreme loads in civil engineering: study of their application in a realistic steel portico

Guaranteeing the use of Shape Memory Alloys (SMA) in mitigation of extreme load effects requires a deep study of the SMA behavior according to the specific requirements of the applications in damping. The damper was defined according the expected requirements (length of SMA and number of SMA wires). It is applied to two types of alloys (CuAlBe and NiTi) in the diagonals of a realistic steel portico (2.47 m x 4.10 m). The measurements establish that the used SMA reduces the oscillation amplitude to a less than a half.Preprin

Amelioration and retrofitting of educational buildings

Following a seismic event that occurred years ago in Central Italy, the public opinion was growing and growing a concern on the adequacy of educational buildings all across Italy. This activated several political decisions and a consequent technical effort is in progress. Technically speaking one has to manage the classical problem of retrofitting existing buildings. However, the legal environment goes across national codes, targeted guidelines and the professional need of achieving pragmatic solutions based on ethical and social acceptation schemes.This paper introduces the topic in its worldwide exception and focuses then on some operative aspects in the Italian situation. It outlines the consolidated steps along this technical process and emphasizes the weak aspects one meets when going across the designers' reports

CONTROL LAW ON ROM

Summary The design of a control law requires two preliminary actions: to introduce a numerical model of the system to be controlled, together with its reduced-order approximation, and to fix the number and positions of the actuators, together with those of the sensors providing the feedback. The link between measured acceleration quantities and model variables was successfully demanded to the Kalman filter in seismic applications. When moving to wind excitation, the standard approach is no longer viable, and one meets several options, which are discussed in the paper. A timber footbridge is studied to provide a numerical example. Copyright © 2015 John Wiley & Sons, Ltd

Designing the control law on reduced-order models of large structural systems

The design of a control law requires two preliminary actions: to introduce a numerical model of the system to be controlled, together with its reduced-order approximation, and to fix the number and positions of the actuators, together with those of the sensors providing the feedback. The link between measured acceleration quantities and model variables was successfully demanded to the Kalman filter in seismic applications. When moving to wind excitation, the standard approach is no longer viable, and one meets several options, which are discussed in the paper. A timber footbridge is studied to provide a numerical example.