86,741 research outputs found
HIL Excitation in the Damage Assessment of a Timber Footbridge
No full textCasciati, Sara; Faravelli, Lucia; Casciati, Fabio
Edited by: Chang, FK; Kopsaftopoulos, F
Conference: Date:
Sponsor(s): Natl Sci Fdn; Air Force Off Sci Res; Boeing; Airbus; Embraer; Verizo
Semi-active electro-inductive devices: Characterization and modelling
No full textElectro-inductive devices have recently been introduced to implement passive control schemes in special classes of structures. Their fascinating feature is the feasibility of large devices, to be installed, for instance, in long span bridges, much shorter than hydraulic dampers with identical maximum span. The characterization of an electro-inductive device with semi-active behavior is presented in detail in this paper. The paper also discusses ways of building a semi-active device, and details its passive control function
Validation range for KF data fusion devices
No full textSensing devices are the main support for any experimental activity. The user expects that they are transparent, i.e., any measurement provides an assessment of a physical variable. Recent microelectronics developments caused significant modifications in the products offered by the market. Data fusion is the source of a recent jump in that technology, but the transparency of the result is no longer evident. In this paper, the authors consider the data fusion of displacement and acceleration measurements via a Kalman filter. The assemblage of two sensors is produced from scratch, and the critical aspects of the consequent data fusion are emphasized
"Chaotic Motion and Stochastic Excitation."
No full textAttention is focused on the chaotic behaviour of dynamical systems under stochastic excitation. Characterization techniques associated with Poincare sections, Lyapunov exponents, capacity and information dimensions, power spectra and probability densities are used for a non-linear single-degree-of-freedom system. It is shown that it is virtually impossible to distinguish between chaotic and non-chaotic stochastic motion when a relatively high intensity of the external excitation is involved. While looking for a transition criterion, the algorithmic experience on the subject is increased
Seismic reliability of a cable-stayed bridge retrofitted with hysteretic devices
No full textThis study evaluates the fragility curves of a cable-stayed bridge by an analytical approach based oil time history analysis. The presentation of the vulnerability information in the form of fragility curves is a widely practiced approach when several uncertain sources are involved. The ASCE benchmark problem of a cable-stayed bridge is considered as a case study. A passive control technique is adopted and results are compared in term of fragility curves, In order to consider the uncertainties related to the ground motion 24 ground motion time history Lire considered, corresponding to four different hazard levels, while the uncertain ties in the structural characteristics are introduced by defining the different performance thresholds as random variables. The fragility evaluation shows how important a estimation of the limit state is for the comparison of different retrofit technique
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