236 research outputs found
Vulnerability assessment of the S. João de Loure Bridge: Vouga’s river
Steel bridges are particularly sensible to corrosion, which can put at risk the structural safety by affecting the joint elements. Having this in mind, the objective of this work was to evaluate the influence of the joint's stiffness in the structural response of the S. João de Loure steel bridge. An improved model was developed for the bridge on the structural analysis software SAP2000. Maximum deflection, axial forces and corresponding stresses, and natural frequencies, were analyzed. Numerical results allow concluding about the influence of the joint's stiffness in the structural response of the bridge
S. João de Loure Bridge: vulnerability assessment and study of a common strengthening solution
This paper presents a structural vulnerability assessment of the steel bridge S. João de Loure. A structural model of the bridge was created and the influence of the joint’s stiffness on its structural response was evaluated using the structural analysis software SAP2000. Natural frequencies, axial forces and corresponding stress, and maximum mid-span deflection, were analyzed. A common strengthening solution with prestressing cables was studied intending to reduce the bridge’s mid-span deflection
The effect of the number of response cycles on the behaviour of reinforced concrete elements subject to cyclic loading
The development of damage in reinforced concrete (RC) structures is a cumulative process. Some damage
indices used to quantify damage make use of the number of response cycles as an Engineering Demand
Parameter (EDP) relating with damage development. Other indices make use of deformation in terms of
displacement or chord rotation. These functions are generally a function of whether the response is monotonic or
cyclic, and are insensitive to the number of major deflection cycles leading to that state of damage. Many such
relations are derived from experimental data from low-cycle fatigue tests performed on RC elements. The
loading in such tests generally consists of either a monotonic increase in load or a gradually increasing cyclic
load. Since damage development is a cumulative process, and hence depends on the load history, the loading
pattern in low-cycle fatigue tests for assessment purposes should reflect the response of an earthquake. This
paper will discuss a procedure to determine a loading history for cyclic tests, based on earthquake demands. The
preliminary results of a campaign of low-cycle fatigue tests on RC elements to investigate the effect of using
different load histories are also discussed
Experimental and numerical analysis of the cyclic behaviour of RC beam-column connections with plain reinforcing bars
The information available in the literature about the cyclic behaviour of reinforced concrete elements with plain reinforcing bars is scarce. As a consequence, the influence of bar slippage in elements with plain bars is not yet comprehensively understood. In this paper are presented and discussed the main results of the cyclic tests carried out on five full-scale reinforced concrete beam-column joints with plain bars and without specific detailing for seismic demands. An additional joint specimen with deformed bars was also tested for comparison. Furthermore, numerical models were built to simulate the response of two of the specimens. Particular attention was given to the influence of bar slippage. The results of the conducted analyses underline the importance of accounting for bond-slip in the numerical modelling of elements with plain bars and also highlight the need for specific models to simulate the effects of this mechanism in the presence of plain bars
Materials and techniques of Art Nouveau architecture in Italy and Portugal: a first insight for an European route to consistent restoration
The results of the investigations on building materials and techniques of Casa Major Pessoa, a typical Art
Nouveau construction in Aveiro (Portugal), and two coeval Art Nouveau buildings in Bologna (Italy) are presented
as a methodological contribution to the restoration of this kind of buildings. This is the first step to
ascertain the existence of a common thread between local materials, technologies and architecture in European
countries at the same period. A holistic approach was adopted: materials were investigated along with
architectural, structural and technological features, in order to achieve a first insight into the Art Nouveau
architecture in Europe in particular for its consistent restoration without loss of historical memory
Searching for sectoral patterns of innovation in european manufacturing industry
The present paper is conducted under the research project “Enterprise of the Future:
Trends and Scenarios towards Competitiveness” which attempts to disclosure
determinants of future enterprise competitiveness. Innovation is not only a must today
but also an imperative in future competitiveness scenarios. In modern evolutionary
economics it is argued that sector-specific factors are one of the key factors explaining
innovative behaviour and performance of firms. Several contributions have pointed that
industries largely differ in terms of knowledge base and technological sources,
opportunities and appropriation of innovative activities, technological trajectories and
firms’ strategies. Using as background Pavitt’s taxonomy, this paper explores the
nature, extent and sources of variety of innovation in the manufacturing industry,
aiming at identifying common patterns across industries, and sectoral patterns across
countries. This paper presents evidence based on the aggregated results of the last IV
Community Innovation Survey released by EUROSTAT (CIS4), for which data is
available for a number of industries and countries
Directions in entrepreneurship education in Europe
An extraordinary proliferation of entrepreneurship courses and programs was and still is underway
in colleges and universities worldwide. In Europe this phenomenon has been further stimulated
by the focus on Entrepreneurship as key objective for the implementation of the Europe2020
strategy (EC, 2010).
This paper provides a systematized overview of patterns and directions in EE in Europe in recent
years. We conduct a review of the published research of the theme with an European focus in an
attempt to organize the literature along precise lines. When possible we use empirical findings to
sustain our arguments. Systematizing the existing literature is a necessary step in developing the
field. For researchers, this overview will be constructive in providing an analysis of the directions
of published research and in setting up a research agenda for the future. It also raises awareness
with regard to entrepreneurship, and in particular, to its potential contribution to the individuals
and to the competitiveness of economies. The empirical analysis adds to our knowledge about the
current situation of EE in practice in Europe
Dynamic nonlinear analyses for the 4-storey infilled R/C frame: study of a retrofitting solution
A research project on assessment and retrofitting of R/C frame structures is currently being developed under the research programme of the ICONS TMR-research network. This paper presents and discusses the preliminary experimental results from a 4-storey bare frame representative of the common practice of 40~50 years ago in most south European countries and devotes special attention to the study of a retrofitting solution based on bracing and rubber dissipaters, which intends to increase stiffness and damping reducing consequently the earthquake deformation demands.O estudo aqui apresentado concentra-se numa solução de reforço de um pórtico utilizando contraventamentos (k-bracing) com perfis de aço em conjunto com elementos elastoméricos de dissipação. Os resultados das análises não lineares da estrutura com e sem alvenaria e com reforço são apresentados e discutidos. Na segunda parte da comunicação apresentam-se os resultados experimentais já disponíveis e discute-se o problema da modelação recorrendo aos resultados experimentais e comparando os resultados obtidos com diferentes tipos de modelos
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