Modelling The Fire Performance of Structural Timber-Concrete Composite Floors

2014 ◽  
Vol 5 (2) ◽  
pp. 113-124 ◽  
Author(s):  
James O'Neill ◽  
Anthony Abu ◽  
David Carradine ◽  
Peter Moss ◽  
Andrew Buchanan
Keyword(s):  
Numerical Modelling ◽  
Fire Resistance ◽  
Experimental Testing ◽  
Mechanical Analysis ◽  
Fire Performance ◽  
Finite Element Software ◽  
Wide Range ◽  
Floor Systems ◽  
3D Numerical Modelling ◽  
Full Scale Tests

This paper describes numerical modelling to predict the fire resistance of engineered timber-concrete composite floor systems. The paper describes 3D numerical modelling of the floor systems using finite element software, carried out as a sequential thermo-mechanical analysis. Experimental testing of these floor assemblies has also been undertaken to validate the models, with multiple full scale tests conducted to determine the failure mechanisms and assess fire damage to the system components. The final outcome of this research is the development of simplified design methods for calculating the fire resistance of a wide range of engineered timber floor systems, as part of a larger research project on multi-storey timber buildings.

Fire resistance tests on timber beam-to-column shear connections

2016 ◽  
Vol 7 (1) ◽  
pp. 41-57 ◽  
Author(s):  
Pedro Palma ◽  
Andrea Frangi ◽  
Erich Hugi ◽  
Paulo Cachim ◽  
Helena Cruz
Keyword(s):  
Fire Resistance ◽  
Negative Influence ◽  
Fire Behaviour ◽  
Timber Beam ◽  
Content Type ◽  
Experimental Programme ◽  
Shear Connections ◽  
Wide Range ◽  
Full Scale Tests ◽  
Resistance Tests

Purpose This paper aims to present the results of an extensive experimental programme on the fire behaviour of timber beam-to-column shear connections, loaded perpendicularly to the grain. Design/methodology/approach The experimental programme comprised tests at normal temperature and loaded fire resistance tests on beam-to-column connections in shear. Twenty-four full-scale tests at normal temperature were performed covering nine different connection typologies, and 19 loaded fire resistance tests were conducted including 11 connections typologies. Findings The results of the fire resistance tests show that the tested typologies of steel-to-timber dowelled connections reached more than 30 and even 60 minutes of fire resistance. However, aspects such as a wider gap between the beam and the column, reduced dowel spacing, and the presence of reinforcement with self-drilling screws all have a negative influence on the fire resistance. Originality/value The experimental programme addressed the fire behaviour of timber beam-to-column shear connections loaded perpendicularly to the grain in a systematic way testing a wide range of common connection typologies significantly enlarging their experimental background.

Influence of Crack Front Shape on 3D Numerical Modelling of Plasticity-Induced Closure of Short and Long Fatigue Cracks

2013 ◽  
Vol 577-578 ◽  
pp. 213-216
Author(s):  
S. Fiordalisi ◽  
C. Gardin ◽  
C. Sarrazin-Baudoux ◽  
M. Arzaghi ◽  
Jean Petit
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Numerical Modelling ◽  
Crack Front ◽  
Stress Intensity Factor Range ◽  
Finite Element Software ◽  
Curved Crack ◽  
3D Numerical Modelling ◽  
Front Shape

The simultaneous effect of crack length and crack front shape on plasticity-induced crack closure (PICC) for a 304L austenitic stainless steel is simulated through 3D numerical modelling using finite element software Abaqus for through-thickness cracks with different curved crack fronts in CT specimens in comparison with bidimensional through crack with a straight front. The influence of possible loading history effect is avoided by applying constant K amplitude. The local stress intensity factor range for crack opening Kopis evaluated from the simulation of the loss of the last local contact between the crack lips near the crack tip. The pertinence of the different crack front shapes is discussed in term of the effective stress intensity factor range Keffand in comparison with the experimental crack front observations.

scholarly journals Relationship between the Stereocomplex Crystallization Behavior and Mechanical Properties of PLLA/PDLA Blends

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1851
Author(s):  
Hye-Seon Park ◽  
Chang-Kook Hong
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Crystallization Behavior ◽  
Mechanical Analysis ◽  
X Ray Diffraction ◽  
Nucleation Agent ◽  
Scanning Calorimetry ◽  
Nucleation Sites ◽  
Wide Range ◽  
Degree Of Crystallization

Poly (l-lactic acid) (PLLA) is a promising biomedical polymer material with a wide range of applications. The diverse enantiomeric forms of PLLA provide great opportunities for thermal and mechanical enhancement through stereocomplex formation. The addition of poly (d-lactic acid) (PDLA) as a nucleation agent and the formation of stereocomplex crystallization (SC) have been proven to be an effective method to improve the crystallization and mechanical properties of the PLLA. In this study, PLLA was blended with different amounts of PDLA through a melt blending process and their properties were calculated. The effect of the PDLA on the crystallization behavior, thermal, and mechanical properties of PLLA were investigated systematically by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), polarized optical microscopy (POM), dynamic mechanical analysis (DMA), and tensile test. Based on our findings, SC formed easily when PDLA content was increased, and acts as nucleation sites. Both SC and homo crystals (HC) were observed in the PLLA/PDLA blends. As the content of PDLA increased, the degree of crystallization increased, and the mechanical strength also increased.

Performance in Fire of Fibre Reinforced Polymer Strengthened Concrete Beams and Columns: Recent Research and Implications for Design

2014 ◽  
Vol 5 (4) ◽  
pp. 353-366 ◽  
Author(s):  
Mark Green ◽  
Kevin Hollingshead ◽  
Noureddine Bénichou
Keyword(s):  
Conceptual Model ◽  
Concrete Beams ◽  
Design Tool ◽  
Fire Performance ◽  
Reinforced Polymers ◽  
Reinforced Polymer ◽  
Practical Design ◽  
Fibre Reinforced Polymer ◽  
Full Scale Tests ◽  
In Fire

This paper considers the fire performance of concrete beams and columns that have been strengthened with fibre reinforced polymers (FRPs). Results from four recent full-scale tests are presented. A newly developed type of insulation was employed and the thickness of the insulation (15 to 20 mm) was approximately half that provided in earlier tests. All of the members survived four hours of the fire exposure. A conceptual model for design to determine when insulation is required is also presented. Further research needed to fully develop the conceptual model to a more practical design tool is outlined.

A Calculation Method of Magnetic Anomaly Field Distribution of Ellipsoid with Arbitrary Posture

2021 ◽  
Author(s):  
Song-tong Han ◽  
Bo Zhang ◽  
Xiao-li Rong ◽  
Lei-xiang Bian ◽  
Guo-kai Zhang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Magnetic Anomaly ◽  
Field Distribution ◽  
Calculation Method ◽  
Gravity Potential ◽  
Anomaly Field ◽  
Finite Element Software ◽  
Wide Range ◽  
Distribution Equation

The ellipsoidal magnetization model has a wide range of application scenarios. For example, in aviation magnetic field prospecting, mineral prospecting, seabed prospecting, and UXO (unexploded ordnance) detection. However, because the existing ellipsoid magnetization formula is relatively complicated, the detection model is usually replaced by a dipole. Such a model increases the error probability and poses a significant challenge for subsequent imaging and pattern recognition. Based on the distribution of ellipsoid gravity potential and magnetic potential, the magnetic anomaly field distribution equation generated by the ellipsoid is deduced by changing the aspect ratio, making the ellipsoid equivalent to a sphere. The result of formula derivation shows that the two magnetic anomaly fields are consistent. This paper uses COMSOL finite element software to model UXO, ellipsoids, and spheres and analyzes magnetic anomalies. The conclusion shows that the ellipsoid model can completely replace the UXO model when the error range of 1nT is satisfied. Finally, we established two sets of ellipsoids and calculated the magnetic anomalous field distributions on different planes using deduction formulas and finite element software. We compared the experimental results and found that the relative error of the two sets of data was within [Formula: see text]‰. Error analysis found that the error distribution is standardized and conforms to the normal distribution. The above mathematical analysis and finite element simulation prove that the calculation method is simple and reliable and provides a magnetic field distribution equation for subsequent UXO inversion.

scholarly journals STUDY OF THE FIRE PERFORMANCE OF HYBRID STEEL-TIMBER CONNECTIONS WITH FULL-SCALE TESTS AND FINITE ELEMENT MODELLING

2016 ◽  
Author(s):  
Aaron O. Akotuah ◽  
Sabah G. Ali ◽  
Jeffrey Erochko ◽  
Xia Zhang ◽  
George V. Hadjisophocleous
Keyword(s):  
Finite Element ◽  
Load Ratio ◽  
Full Scale ◽  
Test Results ◽  
Structural Members ◽  
Fire Performance ◽  
Shear Connection ◽  
Timber Connections ◽  
Full Scale Tests ◽  
Connection Design

Connection design is critical in timber buildings since the connections tend to have lower strength than the structural members themselves and they tend to fail in a brittle manner. The effect of connection geometry on the fire performance of a hybrid steel-timber shear connection is investigated by full-scale testing. These tests were conducted by exposing the test specimens to the standard time-temperature curve defined by CAN/ULC-S101 (CAN/ULC-S101, 2007). Test results showed that the fire resistance of these connections depends on the load ratio, the type of connection and the relative exposure of the steel plate to fire. Finite element models of the connections under fire were constructed using ABAQUS/CAE and these were validated using the test results. These numerical model results correlate well with test results with ±8.32% variation.

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