1,721,087 research outputs found
Fire resistance evaluation through fragility curves
No full textSince the FSE has been introduced, designers have been equipped with tools that allow optimising
the performance of structures in fire. Vulnerability assessment, evaluated by stochastic approach
has become of increasing interest in the international research, also driven by insurance company
needs. The paper shows the application of probabilistic tools for assessing mechanical behaviour at
elevated temperature of common structural typologies (i.e. steel, concrete and composite beams
with or without axial restraints) at different load levels. The fluid dynamic aspects are included in
the statistical analysis, with natural fires selected in order to analyse the influence of the specific
fire load and the ventilation condition of the compartment by means of a two-zone model. Results
are summarized in fragility curves giving time collapse or maximum displacement limit state
attainment. In future, fragility curves could be built for complex structures to provide a tool for
insurance companies that allows rapid assessment of structural vulnerability to fire
Performance of steel-concrete composite bridges in fire
No full textIn assessing the damage on bridges caused by a fire, we should not only consider the possibility of
structural collapse, which often is avoided thanks to the beneficial effect of the ventilation that cools
the hot fumes propagating during fire. Indeed checks on the maximum deflection that the structure
can undergo during fire can be more significant for the functionality after fire of electrical, gas and
water systems often included in the bridge structures connecting different urban and extra urban
areas. Therefore, fluid dynamic and thermomechanical numerical analyses were performed to
simulate the behavior of typical bridges of the national highway during a fire, to identify possible
fire risk mitigation for avoiding the collapse of the structures and the damage of the facilities
Experimental analysis on the effectiveness of intumescent coatings in fire
No full textIntumescent coatings (IC) are the most frequently used fireproof materials for protecting steel structures
in the current market. In case of fire, the IC changes chemical, physical and thermal properties. The
paper shows preliminary results of an experimental study consisting in about 40 lab scale tests, in which
the effect of section factor, IC dry thickness, shape of the samples (with same section factor) and input
fire curves are considered in the IC assessment. This characterization is essential for modelling
structural members protected by IC through FE analysis in the framework of fire safety engineering
applications and for designing the required IC thickness to protect the structural members
Mixed finite elements for the elastoplastic analysis of 2D continua
Full text linkThe paper aims to formulate assumed stress finite elements for the analysis of elastoplastic structures. The interpolations of the displacement and stress fields, typical of the elastic version of the mixed elements, is enriched with the FEM representation of the plastic strain field. The formulation of the elastoplastic problem of the element is then established, consistently, with respect to its variational basis based on the weak enforcement of the compatibility condition. Its correlation with the Haar–Karman principle leads to a minimization problem of a quadratic functional subjected to a linearized form of the plastic admissibility constraints
Discrete planes formulation of mixed finite elements for the analysis of 2D elasto-plastic solids
No full textUn modello FEM per l'analisi nonlineare alla Koiter di strutture a parete sottile in materiale composito
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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