Error study of a hybrid testing system of structures through a state-space model

Experimental methods such as hybrid or pseudo-dynamic tests are always subjected to experimental errors which effect on the obtained response is important to assess. An analytical linear model formulated on state-space equations has been developed for a multi DoF hybrid testing system including the components of the control and the specimen. For an example of a single DoF steel frame, the parameters of the model have been calibrated through comparison with experimental data of the control system. The model has been used to predict in pseudo-dynamic tests on such specimen the control errors and their consequences in terms of eigenfrequency and damping distortion in the test response. These predictions match with the observed experimental data and allow understanding, for example, the effects on the response of performing the test at different testing speeds or for different parameter configurations of the control algorithm.JRC.G.5-European laboratory for structural assessmen

On dynamic control of structural vibrations research activities conducted within the covicocepad project

This paper provides an overview on the latest research and development (R&D) activities carried out under the project entitled Comparison of Vibration Control in Civil Engineering Using Passive and Active Dampers (COVICOCEPAD) which was executed within the framework of the Eurocores project, as a part of the sixth European program. The general interest of the paper relies upon the variety of presented highlights relevant to structural control research streams currently under development in a number of European universities, addressing the use of tuned liquid dampers (TLD), base isolation devices, magneto-rheological (MR) dampers and a hybrid technique using both devices together. The paper also provides details of a few new testing equipments which are in use of the relevant laboratories. Finally, research projects in the field of structural control at the involved research institutes are reviewed.info:eu-repo/semantics/publishedVersio

R&D on control of vibrations under covicocepad during 2007-2008

This paper provides information on the latest R&D within COVICOCEPAD project approved in the framework of Eurocores program. It addresses the use of TLD, base isolation devices, MR dampers and a hybrid technique using both devices together. Some results are provided associated with calibration of a MR damper at FEUP, as well as its inclusion in a small scale laboratory set-up with proper equations of motion of the controlled smart structure. An application of semi-active control technique to a bridge is outlined. Further remarks and details on future tests to be performed in LNEC shaking table, within COVICOCEPAD project, are provided

NSF/ESF Workshop on Smart Structures and Advanced Sensors, Santorini Island, Greece, June 26-28, 2005: Structural Actuation and Adaptation Working Group

This document is a result of discussions that took place during the workshop. It describes current state of research and development (R&D) in the areas of structural actuation and adaptation in the context of smart structures and advanced sensors (SS&AS), and provides an outlook to guide future R&D efforts to develop technologies needed to build SS&AS. The discussions took place among the members of the Structural Actuation and Adaptation Working Group, as well as in general sessions including all four working groups. Participants included members of academia, industry, and government from the US and Europe, and representatives from China, Japan, and Korea

Progetti di ricerca internazionali sulle tecnologie avanzate di protezione sismica

Le tecnologie innovative di protezione sismica delle strutture, che da tempo costituiscono un argomento di punta della ricerca nel settore dell¿ingegneria sismica, sono divenute oggetto di crescente interesse anche da parte della comunità tecnica e professionale. L¿adozione di tali tecnologie pone, tuttavia, alcune nuove problematiche rispetto al progetto delle strutture antisismiche tradizionali, per risolvere le quali risulta necessaria una conoscenza di base dei principi di funzionamento e delle prestazioni offerte dai diversi tipi di dispositivi in commercio e dai sistemi di protezione che li includono. Inoltre, come per qualsiasi percorso progettuale, devono essere acquisiti gli opportuni metodi di analisi, di modellazione, di dimensionamento e di verifica. Il volume raccoglie i testi delle lezioni tenute nel corso avanzato di formazione professionale ¿Tecnologie innovative di protezione sismica delle strutture¿, svoltosi a Udine nel 2006, che si è proposto di fornire contributi di risposta a tali esigenze, con riferimento a diverse tipologie di dispositivi e di tecniche di protezione, nonché ad un selezionato repertorio di applicazioni pratiche. I testi sono stati predisposti dai relatori aggiornandone i contenuti agli sviluppi delle rispettive attività di studio e di ricerca svolte, sugli argomenti trattati, sino alla fine del 2008.JRC.DG.G.5-European laboratory for structural assessmen

Experimental Studies of Loading Rate Effects on Reinforced Concrete Columns

Abstract not availableNA-NOT AVAILABL

Technology of Semiactive Devices and Applications in Vibration Mitigation

Civil engineering structures do not show the innovation rate which characterizes mechanical and aerospace engineering. There are three ingredients able to generate innovation: the design rationale, the construction materials and the quality process. The first ingredient has not seen revolutions in the last century, while the second suggested fascinating innovative solutions but they are still under durability exam to satisfy the long expected lifetimes which characterize civil infrastructure components. Therefore, certification and quality control were driving the innovation of the last half century within the usual framework of increasing the strength of the structure. It can be mainly obtained by making larger and larger sections, so that stiffer and more massive buildings results. One pay attention here to carrying capacity and, hence, the framework can be referred to as capacity design. This approach is unable to satisfy some needs which have risen in the last years, but the last decade introduced structural control technologies which offer very appealing solutions. In this field the objection on the power unavailability during events which seriously engage the structure, addresses the attention to passive devices, but a further class of semiactive control devices was soon introduced and is presented here.JRC.G.5-European laboratory for structural assessmen

Reliability of dynamic and hybrid tests in the presence of control errors

The deleterious effect of control errors in the obtained response for shaking-table, pseudo-dynamic and hybrid tests can be quantified in a standard way by assessing the frequency and damping distortion in the obtained response as identified from equivalent linear models. The identified linear models are based only on the measurements done during the experiment, which increases the generality and applicability of the proposed strategy.JRC.DG.G.5-European laboratory for structural assessmen

Reliability Assessment in Pseudo-Dynamic and Dynamic Tests

A general approach to the definition and assessment of response errors in dynamic and pseudo-dynamic tests is presented. By use of complete measurements during the test, either the characteristics of the experimental and the prototype system can be estimated by means of a linear ideal representation. This allows to compare quantitatively in terms of eigenfrequencies and damping ratios the experimental system and the prototype one. In the pseudo-dynamic test, the apparent effect of the control errors is a modification of the linear-equivalent matrices of stiffness and damping which are identified from the experimental data. In the shaking-table test, the control errors may introduce spurious excitation that, if properly measured, can also be shown to modify the response characteristics.JRC.DG.G.5-European laboratory for structural assessmen