Filtern
Erscheinungsjahr
Dokumenttyp
Referierte Publikation
- ja (19) (entfernen)
Schlagworte
- Fire resistance (4)
- Fire stability (3)
- Fully developed fire (3)
- Concrete (2)
- Concrete filled tube (CFT) column (2)
- Constitutive equation (2)
- Seismically damaged column (2)
- Berechnungs- und Bemessungsverfahren (1)
- Brandschutz (1)
- Buckling (1)
- Carbon fiber reinforced polymer (CFRP) (1)
- Carbon-fibre-reinforced (1)
- Carbon-fibre-reinforced plastics (1)
- Circular (1)
- Column (1)
- Composite (1)
- Composites (1)
- Core materials (1)
- Creep (1)
- Damage location (1)
- EC (1)
- Endochronic plasticity (1)
- Eurocode (1)
- Feuerwiderstandsdauer (1)
- Finite element analysis (1)
- Finite element method (1)
- Finite element model (1)
- Finite-Elemente-Methode (1)
- Fire (1)
- Fire after earthquake (1)
- Fire engineering (1)
- Fire performance (1)
- Fire protective coatings (1)
- Fire spalling (1)
- Fire testing (1)
- Glass-fibre-reinforced plastics (1)
- High-temperature properties (1)
- Hochfester Beton (1)
- Hochleistungsbeton (1)
- Intumescence (1)
- Large scale tests (1)
- Mechanical testing (1)
- Modellierung (1)
- Multi-hazard incident (1)
- Nichtlineare Berechnungsverfahren (1)
- Normen (1)
- Normen/Vorschriften/Richtlinien (1)
- Post-crash scenario (1)
- Post-earthquake fire (1)
- Resistance (1)
- Restraining (1)
- Standardised fire resistance tests (1)
- Structural integrity (1)
- Thermogravimetric analyses (1)
- Thermomechanical properties (1)
- UMAT (1)
- Verformungsverhalten (1)
- Versuche (1)
- Viscoplasticity (1)
- Weathering (1)
Organisationseinheit der BAM
Isotrope nichtlineare Viskoelastizität mit Hilfe von Maßstabsfunktionen der Gedächtnisspannung
(1994)
The recommendation is based on the co-authors’ work organized by the RILEM TC 256-SPF “Spalling of concrete due to fire: testing and modelling”. It aims to provide useful information, guidance and best practices in fire spalling assessment to laboratories that perform large-scale tests based on fire resistance test standards. It provides guidance on the spalling observation techniques during testing, as well as post-test spalling quantification/assessment methods. This document is intended to be used in conjunction with the fire resistance test standards, e.g. EN 1363-1 and ISO 834-1.
Most of the previous studies on reinforced concrete columns with elastically restrained thermal elongation were carried out on square, rectangular or '+'-shaped cross sections. The number of fire resistance tests on circular reinforced concrete columns with elastically restrained thermal elongation is still very small. In order to examine the influence of several parameters on the behaviour in fire of this type of columns several fire resistance tests were carried out. The parameters tested were the load and restraint level, slenderness of the column and longitudinal reinforcement ratio. In the fire resistance tests the specimens were exposed to the ISO 834 standard fire curve and the critical time (fire resistance) and temperature and failure modes were determined. The test results showed that the spalling phenomenon may occur in circular columns and so reducing its fire resistance. The increasing of the load level led to a reduction while the increasing of the longitudinal reinforcement ratio or the decreasing of the slenderness of the columns led to an increasing of their fire resistance. The restraint level might not be much relevant on the fire resistance of circular reinforced concrete columns.
In this paper, a nonlinear three-dimensional finite element (FE) model was developed and validated to study the effect of seismic damage location on the response of concrete filled tube (CFT) columns at fire after earthquakes. Three analyses were conducted consecutively in the modelling, namely, cyclic, thermal and structural. Results of the cyclic loading analysis comprising residual deformations were applied as the Initial condition to the thermal-stress model, replicating the seismic performance of column.
Following, a nonlinear sequentially coupled-thermal stress Analysis was carried out to investigate the fire response of CFT columns after the seismic event. Three damage scenarios were contemplated, considering any possible potential damages that could be generated by the earthquake loading on CFT columns. The accuracy of the proposed FE model was examined by comparing the numerical results with that of available tests on fire and cyclic loading. By means of the validated model, the performance of damaged CFT columns was then investigated under fire after earthquakes. The level of damage was assumed as a high damage level, presuming that the column reached 50% of ist lateral resistance while still maintaining its overall stability after the earthquake. The results were presented broadly, including the axial deformation history as well as the fire resistance time for CFT columns. To have a comprehensive insight on the influence of damage location in columns, the fire response of damaged specimens was compared with that of an intact one.
In this study, a nonlinear three-dimensional finite element (FE) model was developed and validated to investigate the response of concrete filled tube (CFT) columns subjected to post-earthquake fires. Three steps were considered successively in the modelling, namely, cyclic, thermal and structural analyses. Outputs from the cyclic loading including residual deformationswere imposed as an initial condition to the thermal-stress model, imitating the seismic response of the column. Subsequently, a nonlinear sequentially thermal-stress analysis was conducted to simulate the fire response of column after the earthquake. The proposed FE model was validated by comparing the simulation resultswith the observations of full-scale fire and cyclic tests available in the literature.
The validated numericalmodelwas then used to study the behavior of CFT columns under the combined action of earthquake and fire as a multi-hazard event. Three probable seismic damage scenarios were considered in the column, namely, middle length, bottom and top end region damages. The level of damage was assumed as a high damage level, presuming that the column reached 50% of its lateral resistance while still maintaining ist overall stability after the earthquake. The results showed that the top and bottom end region damages have not significantly influence the fire response of the damaged column. Besides, the column with the middle span damage performed a lesser fire resistance time owing to the coincidence of damage location to that of onset of global buckling.
The fire stability of carbon fiber reinforced polymer (CFRP) shell structures was investigated using an intermediate-scale test setup. The shell specimens are representative of typical load-bearing CFRPs in modern civil aviation. The CFRP shell specimens were exposed to a fully developed fire with direct flame impingement to one side at a heat flux of 182 kW/m2. Specimens were simultaneously loaded with constant compressive force equal to 40% of the ultimate failure load. CFRP shells and four different fire retarding configurations, using integrated protective layers, were investigated. Unprotected CFRP specimens failed after just 27 s. Specimens with integrated protective layers with low heat conductivity and high burn-through resistance showed the most promising results. An integrated titanium foil decelerated the decomposition of the epoxy matrix and increased the time to failure by 68% compared to the unprotected CFRP shell.