Fire analysis of timber composite beams with interlayer slip

The purpose of this paper is to model the behaviour of timber composite beams with interlayer slip, when simultaneously exposed to static loading and fire. A transient moisture-thermal state of a timber beam is analysed by the Luikov equations, and mechanical behaviour of timber composite beam is modelled by Reissner's kinematic equations. The model can handle layers of different materials. Material properties are functions of temperature. The thermal model is validated against the experimental data presented in the literature. Generally, the model provides excellent agreement with the experimental data. It is shown that the material properties of timber play an important role in the fire resistance analysis of timber structures when exposed to fire

Fire analysis of steel-concrete composite beam with interlayer slip

The paper discusses the effects of slip and moisture transfer on the behaviour of a planar steel-concrete composite beam subject to fire conditions. The moisture and heat transfer is assumed to be governed by a coupled problem, while the mechanical behaviour accounting for slip between layers is described by strain-based beam finite elements. Hence the fire analysis is perfomed in two separate steps, of which the moisture and heat transfer analysis is performed first, followed by the mechanical analysis. The present novel finite-element formulation proves to be appropriate for the thermo-mechanical analysis of frame-like structures, as it is robust, reliable and accurate. (C) 2010 Elsevier Ltd. All rights reserved

Fire analysis of steel frames with the use of artificial neural networks

The paper presents an alternative approach to the modelling of the mechanical behaviour of steel frame material when exposed to the high temperatures expected in fires. Based on a series of stress-strain curves obtained experimentally for various temperature levels, an artificial neural network (ANN) is employed in the material modelling of steel. Geometrically and materially, a non-linear analysis of plane frame structures subjected to fire is performed by FEM. The numerical results of a simply supported beam are compared with our measurements, and show a good agreement, although the temperature-displacement curves exhibit rather irregular shapes. It can be concluded that ANN is an efficient tool for modelling the material properties of steel frames in fire engineering design studies. (c) 2007 Elsevier Ltd. All rights reserved

Infrared imaging software for jet fire analysis

Jet fires, often originated by the ignition of hydrocarbon sonic jets, are characterized by a high momentum jet flame lifted from the outlet orifice. The high thermal flux released, especially if there is flames impingement on a given equipment, can lead to a domino effect. Therefore, predicting its size and shape is quite interesting in order to foresee the possibility of this effect on a given equipment. Several mathematical models have been proposed to predict jet fires main features, some of them based on experimental data. However, the analysis of jet flames can be sometimes difficult. In this communication, an inhouse infrared imaging software for jet fire analysis is presented, which allows the calculation of different flamegeometry descriptors. A set of capabilities are included in a graphical user-friendly interface that can help users to easily obtain fire metrics. The tool also provides options to export the results for a post-processing analysis useful for risk prevention, such as preventive design and calculation, and emergency protocols design.Postprint (published version

Multi-sensor fire detection by fusing visual and non-visual flame features

This paper proposes a feature-based multi-sensor fire detector operating on ordinary video and long wave infrared (LWIR) thermal images. The detector automatically extracts hot objects from the thermal images by dynamic background subtraction and histogram-based segmentation. Analogously, moving objects are extracted from the ordinary video by intensity-based dynamic background subtraction. These hot and moving objects are then further analyzed using a set of flame features which focus on the distinctive geometric, temporal and spatial disorder characteristics of flame regions. By combining the probabilities of these fast retrievable visual and thermal features, we are able to detect the fire at an early stage. Experiments with video and LWIR sequences of lire and non-fire real case scenarios show good results in id indicate that multi-sensor fire analysis is very promising

Life Safety and Fire Analysis - Aircraft Hangar

A hangar originally built in 1958 then modified and expanded over the years was evaluated using both the prescriptive requirements and a performance analysis. For the prescriptive analysis the building was evaluated against the 2015 International Building Code and the current NFPA codes and in a few cases the Department of Defense (DoD) Unified Facilities Criteria (UFC). During the prescriptive analysis a few areas were identified that do not meet the current codes due to areas being broken up into separate rooms and hallways and rooms being separated by security doors that only allow unobstructed travel in one direction. These modifications over the years have created a few areas that have a common travel paths and dead ends that exceed the requirements as set forth by NFPA 101 Life safety code. Due to the size of the hangar the notification devices installed do not meet the audibility or illumination requirements. It is recommended that the rotating beacons be installed per the new UFC 4-211-01 requirements. For the performance analysis a pool fire created from jet fuel was ignited both under the aircraft and in the vicinity of an aircraft. The hangar was then evaluated for both life safety by verifying that the available safe egress time (ASET) was greater than the required safe egress time (RSET). The RSET was calculated using both hand calculations and a pathfinder computer model. The ASET was determined using a NIST Fire Dynamic Simulator (FDS). The FDS modeling showed that the ASET was significantly greater than the RSET thus there was no issue with life safety. Asset protection from the fire scenarios chosen was not as promising. For both fire scenarios chosen in the hangar the aircraft suffered some damage. It was also determined from the modeling that the current activation sequence of the high expansion foam (HEF) system, using the sprinkler flow switches to activate the system, would be ineffective due to the delay in activating the sprinklers at the 70-ft ceiling level and the mechanical timer in the flow switch. A better way to activate the HEF system would be using multiple optical flame detectors as now required by UFC 4-211-01

FIRE ANALYSIS OF CURVED REINFORCED CONCRETE BEAM

In the present study the fire analysis of a curved reinforced concrete beam exposed to concrete spalling is presented. Due to the complexity of physical and chemical processes in concrete at elevated temperatures, the proposed numerical model is divided into two consecutive mathematically uncoupled phases. In the second phase of the fire analysis a partially coupled numerical model is introduced in order to evaluate the effect of concrete spalling on the behaviour of curved RC beam in fire. In addition, the effect of depth, time development and the length of spalling area on the fire resistance of a curved RC beam is discussed

Flood Analysis Of The Thomas Floods Using NASA Data

This analysis is a follow-on to the Thomas Fire analysis presented by Ross Bagwell ("Fire Analysis of the Thomas Fire Using NASA DATA in a GIS"). The Thomas fire and heavy rains a month later led to the historic flooding. The maps tell the story using NASA Earth Observing System data in concert with Santa Barbara County data

Determination and Fire Analysis of Gob Characteristics Using CFD

Peer ReviewedPostprint (published version