Pseudo-dynamic tests on two buildings retrofitted with damped braces

Seismic tests have been conducted on two 3-storey buildings protected with fluid-viscous spring damper devices. One of the buildings was a reinforced concrete frame with clay elements in the slabs, while the other one was a steel frame with steel/concrete composite slabs. The spring dampers were installed through K bracing in between the floors. The tests were performed by means of the pseudodynamic method on full-size specimens and by implementing a specific compensation strategy for the strain-rate effects at the devices. The tests results allowed to compare the behaviour of the unprotected buildings with several protected configurations showing the benefits of the application of the devices and the characteristics of their behaviour

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

Parametric variation of a coupled pendulum-oscillator system using real-time dynamic substructuring

In this paper, we present results from real-time dynamic substructuring tests used to model the dynamics of a coupled pendulum–oscillator system. The substructuring technique is particularly suitable for systems where the nonlinear and linear parts of the system can be separated. The nonlinear part is built full size and tested physically (the substructure) while the linear part is simulated numerically. Then, in order to replicate the dynamics of the complete system the substructure and the numerical model must be coupled in real time. In this study, we demonstrate how real-time dynamic substructure testing can be used to model systems with strongly nonlinear behaviour using parametric variation. We show that the substructuring results give good qualitative and quantitative agreement with purely numerical simulations of the complete system for a range of parameters values. This includes single parameter bifurcation diagrams, some of which cannot be obtained from a full physical experiment. We also briefly discuss the effects of delay and noise on the stability of the substructured system, and how these effects can be mitigated. Copyright © 2006 John Wiley & Sons, Ltd

Competitive Advantage Through the Customer Involvement in E-commerce Strategies : A Multiple-Case Study in the European Airline Industry

Much research show that strategies of personalization aiming to meet customers' needs and behaviors are an important aspect to influence the competitiveness within an industry. However there is a gap of studies on how airlines use customer involvement for creating personalized strategies in the field of e-commerce while enhancing the competitive advantage. This study is aims to describe how airlines can create personalized e-commerce strategies by considering the customer involvement in order to enhance their competitiveness. In conjunction with this first assumption the study aims to demonstrate how airlines could increase their customer loyalty by implementing the concept of customer relationship management (CRM) within their e-commerce strategies. A theoretical framework has been developed derived from a review of the existing literature in order to describe how airlines can use personalization as a strategy in e-commerce to develop a competitive advantage.  A qualitative multiple-case study has been chosen for this study. Three companies have been studied within the European airline industry and have been led by a deductive approach which will aim to investigate the theoretical framework.The analysis of empirical findings revealed some relevant conclusions, which can bring value to the research area, and also to the practice. The main findings show that airlines are involving customers into their e-commerce strategies in various forms and different levels regarding a specific project. One of the major result of this thesis is that airlines seem to focus on point of contacts with customers external to the e-commerce platform