1,721,180 research outputs found
The seismic behaviour of ancient masonry structures: damage scenariosand role of FRP in retrofit and improvement
No full textreport of key-note lectur
Progetto di rilevamento tridimensionale, modellazione numerica e progettazione del supporto del cavallo di Canova.
No full textAnalytical modelling of FRP strengthened steel beams
No full textIn this paper an analytical procedure to predict flexural behaviour of FRP strengthened steel and steel-composed elements, based on the cross-section behaviour, taking into account non-linear behaviour of the materials with any configuration of FRP reinforcement is shown. Analytical provisions are compared to some experimental results available in literature about flexural behaviour of FRP strengthened steel and steel composed elements showing a good agreement of the results also in the non-linear-phase until failure. © 2008 Taylor & Francis Group, London
Axial Force Estimation in Historical Metal Tie-Rods: Methods, Influencing Parameters, and Laboratory Tests
No full textThis research focuses on estimating the axial force of historical metal tie-rods by means of non-destructive testing (NDT) which provides useful information for calibrating structural models. The first part of this work describes the behavior of tie-rods, emphasizing the key role played by cross-section stiffness, which is usually neglected in the case of cables. Particular attention is then given to common effective parameters and dynamic aspects in terms of acquiring the set-up and which modal parameters to examine.
For new insights into methods for assessing historical tie-rods and evaluating the reliability of analytical and numerical predictions, laboratory tests on four samples with typical cross-sections were carried out on historical metal tie-rods. A set of 224 configurations, including various methods of excitation, boundary conditions, and stress states, were analyzed. In addition to laboratory parameters, this analysis also includes details of sensor positions and number of modes to be examined, and proposes a simplification for less time-consuming tests on-site
Response to discussion by O. Bedair of "Imperfections in steel girder webs with and without perforations under patch loading"
No full textA team of researchers presented their views on the discussion by O. Bedair regarding imperfections in steel girder webs with and without perforations under patch loading. The load was applied at the lower flange to simulate the actual and common situation sting in the longitudinal launching of steel bridges. The girder where initial imperfections were detected and successively implemented in the numerical analysis, was a part of a beam to be placed near midspan that was subjected to inversion of the bending moment and localized load at the lower flange when it came in contact with the sliding device on the pier, during launching. The common of neglecting the contribution of upper and lower flanges and vertical stiffeners or determining the linear buckling load of an open-section girder was adopted
Elasto-plastic behaviour of perforated steel plates subjected to compression and bending
No full textThe aim of this work is to provide some insights into the elasto-plastic behaviour of plate girder web square and rectangular panels with centred and eccentric holes under both compression and in-plane bending moment. The numerical study was validated comparing the numerical results obtained for one simple steel plate configuration with the corresponding experimental results, obtained at the University of Padova, observing the influence of the initial out-of-plane imperfections on the force vs. displacement relationship and ultimate strength. Once validated the numerical approach, the effect of bending moment on the stability of the plate is studied and some differences with respect to the uniform compression load case are shown. The influence of dimension and position of the hole, the plate aspect ratio and the steel grade on elasto-plastic behaviour is observed. Some indications regarding the critical slenderness (at which transition from elastic to plastic collapse occurs) are given for square and rectangular plates with symmetric and eccentric holes having small, medium and large diameter
Imperfections in steel girder webs with and without perforations under patch loading
No full textIn this paper, the problem of stability of web plates with imperfections, subjected to patch load, is studied. The aim is to give some insights about the best way to take into account real imperfections in non-linear stability analyses of plates with and without perforations. In this context, the study is developed on the basis of the measured imperfections or numerically deriving the deformed model (theoretical imperfections). The influence of the patch load length, out-of-plane imperfection amplitude, dimension and position of the hole on stability behaviour and buckling strength are studied comparing some theoretical deformed configurations corresponding to different modal shapes. The results obtained with a three-dimensional model of the whole real beam with stiffeners, with experimentally measured imperfections, and each corresponding single web panel are compared and discussed obtaining some insights about the accuracy of the simplified (and conservative) model of the single panel. The main insights of this work are as follows. The deformed shape, corresponding to the first buckling mode, can be assumed as the initial configuration of the panels with and without holes to study post-critical behaviour until ultimate condition. The shape of the imperfection does not severely change the critical buckling stress. A longer patch load reduces the ultimate stress in the panel. An initial imperfection amplitude of less than 1% of the height of the panel does not reduce the ultimate load by more than about 5%. © 2008 Elsevier Ltd. All rights reserved
Elastic stability of plates with circular and rectangular holes subjected to axial compression and bending moment
No full textIn this paper linear buckling analyses of square and rectangular plates with circular and rectangular holes in various positions subjected to axial compression and bending moment are developed. The aim is to give some practical indications on the best position of the circular hole and the best position and orientation of rectangular holes in steel plates, when axial compression and bending moment act together. Two different orientations are considered for rectangular holes: holes with major dimension parallel to the vertical plate axis (RS holes) and major dimension parallel to horizontal plate axis (RL holes). The effect of bending moment on the stability of the plate is studied and some differences with respect to the uniform compression load case are shown. Some design suggestions on the best orientation of rectangular for stability purposes are given. The influence of dimension and position of perforations on linear buckling behaviour and, in particular, on buckling coefficient of the plate is observed. Some practical design formulations for the calculation of the buckling coefficient, taking into account (a) dimensions and shape (square and rectangular) of the plate, (b) dimensions and shape (circular and rectangular) of the hole, (c) position of the hole (centre in the "maximum" and in the "nodal" point), (d) orientation (RS and RL) of the rectangular hole, and (e) load configuration (uniform compression, combinations of axial compression and bending and pure bending) are finally proposed. © 2008 Elsevier Ltd. All rights reserved
Investigation for the design and control of the repair intervention on historical stone masonry wall
No full text- …
