Fire Situation Research Articles

Influence of Internal Pressure on Hollow Section Steel Members in Fire

Structural steel hollow section members are extensively utilized in civil engineering due to their excellent mechanical performance, favourable geometry for corrosion protection, and aesthetic appeal. Degradation in material properties of steel and thermal expansion at high temperatures must be regarded in designs for fire situations. The closed inner space of hollow sections presents challenges at elevated temperatures. The present study examines the effect of expanding air on the stress state in section walls of hermetically sealed circular and rectangular hollow sections. The effect of the gas pressure is calculated analytically and numerically. The pressure of the expanding air may substantially reduce the capacity of a tubular member. The influence on resistance depends on temperature, volume of the air in the tubular member, and geometry of the hollow section. The results of the study indicate that rectangular hollow sections with relatively large width-to-thickness ratios are more sensitive to internal pressure than circular hollow sections. The temperature range where the adverse effect of internal pressure occurs can include realistic critical temperatures in practical design and therefore deserve special attention to ensure the required safety.

Evaluating the fire behaviour of cement-based lightweight materials with textile waste incorporation using a cone calorimeter

The conscientious utilization of natural resources and the efficient waste management have become a matter of great concern in recent years due to the harmful impacts on the environment. The construction sector presents itself as one of the sectors that most contributes to raw materials consumption and waste generation, demanding the investigation of more sustainable and eco-friendly building materials, where the valorisation of wastes originated from other industries can be promising. Following the sustainability concept in construction materials, this work investigates the potential use of textile waste in cement-based lightweight construction material, evaluating the fire reaction of the material using the cone calorimeter equipment. The samples were tested at three different radiant heat fluxes (35 kW/m², 50 kW/m², 75 kW/m²) to simulate different fire situations. For the highest heat flux, the lightweight construction element with textile waste incorporation showed a Heat Release Rate Average ≤ 18 kW/m², a peak Heat Release Rate Average ≤ 60 kW/m², and a Total Heat Release Average ≤ 33 MJ/m². These results reveal a very satisfactory fire behaviour compared to other materials and show the suitability of using textile waste as lightweight cement-based materials.

Evaluation of the Behavior of Steel–Concrete Composite Flush End-Plate Connections at Ambient Temperature and in a Fire Situation

Evaluation of the Behavior of Steel–Concrete Composite Flush End-Plate Connections at Ambient Temperature and in a Fire Situation

Evaluation of reality and standards for fire evacuation routes in buildings – case study

Any building, at any time could experience a fire. Because of that, occupants need a fire evacuation path that is designed according to the design standards as they are unable to be entirely prepared for fire emergency scenarios. However, the majority of these standards were developed using empirical judgments. The aim of the paper is to determine whether the fire escape exit route design takes into account the demands and behaviour of building occupants or if it only considers the recommendations and regulations already in place. One university building has been chosen for qualitative research, and as a result, students and teachers are the primary target population. The following factors are taken into consideration throughout the research: the number of students and professors, the movement speed of building occupants and persons with special needs, the plan, the number of floors, the width and length of corridors, the location and type of stairways, as well as type, position and geometry of doors. The findings of this case study indicated that younger occupants can safely exit the building, however older occupants and students with disabilities, as well as teaching personnel need more time for evacuation across the same evacuation paths in fire situation. In this regard, the findings of this research paper offer conclusions that might be useful in design and organization of such and similar buildings and environments.

PENGARUH SIMULASI TERHADAP PENINGKATAN PENGETAHUAN DAN KETERAMPILAN APARATUR DINAS PEMADAM KEBAKARAN DAN PENYELAMATAN KABUPATEN SUMBAWA BARAT

The number of fire incidents in West Sumbawa Regency has increased significantly. In response to this problem, the study attempted to examine the issue of evaluating the effect of simulation training on improving the knowledge and skills of the Fire Service apparatus of West Sumbawa Regency. This study used a comparative causal research method involving 30 respondents out of 75 total research respondents and used a quantitative approach to measure the impact of simulation training on increasing the knowledge and skills of the apparatus. From the test results obtained, it has a Cronbach alpah value> 0.804 from the R Tabe value of 0.600 so that the instrument can be declared reliable and has a very high influence on increasing the knowledge and skills of the Fire Apparatus. this supports the hypothesis that simulation training has a positive impact on the knowledge and skills of fire fighting apparatus. The implications of this research provide a basis for the West Sumbawa Regency Fire Service to consider the integration of simulation training as an effective strategy in improving the readiness and skills of the apparatus in dealing with fire and other emergency situations.

화재대응 모의훈련평가시스템 개발에 관한 연구

This study developed a simulated fire response training evaluation system based on the Internet of Things to acquire training participants' initial response skills through realistic and practical fire response training, and continuously improve the response activities of training participants based on a quantitative and objective training evaluation system. With the goal of minimizing the scale of fire damage through rapid and accurate response in the event of an unexpected fire accident by establishing a research process for this purpose, developing a fire response training evaluation system based on the overall technical investigation required for research After the operation test, the evaluation system was installed in the test place, and fire response simulation training was conducted for 20 occupants. Prior to training, the evaluation system smartphone app was used to input the training date and time, and after explaining how to use the evaluation system device to the participants, the training was conducted and the results were analyzed.
 As a result, the fire response simulation training evaluation system developed in this study can produce the behavior of fire smoke and measure the time required for each response step of training participants through the system device as a quantified value, enabling quantitative training evaluation. was derived.
 Through this system development and operation experiment, 1) it is possible to implement a fire training situation similar to an actual fire situation using the fire initial response training evaluation system, and 2), it is possible to evaluate fire training quantitatively by response stage, based on the results As a result, future training feedback and continuous improvement activities are possible, and 3) training participants can learn accurate response behaviors, and evaluation can be objectively and quantitatively measured.

Analyzing Temperature Distribution Patterns on the Facing and Backside Surface: Investigating Combustion Performance of Flame-Retardant Particle Boards Using Aluminum Hypophosphite, Intumescent, and Magnesium Hydroxide Flame Retardants.

Particle boards are manufactured through a hot pressing process using wood materials (natural polymer materials) and adhesive, which find common usage in indoor decorative finishing materials. Flame-retardant particleboard, crucial for fire safety in such applications, undergoes performance analysis that includes assessing temperature distribution across its facing surface and temperature increase on the backside surface during facade combustion, yielding critical insights into fire scenario development. In this study, a compact flame spread apparatus is utilized to examine the flame retardancy and combustion behavior of particle boards, with a specific emphasis on the application of cost-effective flame retardants, encompassing aluminum hypophosphite (ALHP), an intumescent flame retardant (IFR) comprising ammonium polyphosphate (APP), melamine (MEL), and Dipentaerythritol (DPE), alongside magnesium hydroxide (MDH), and their associated combustion characteristics. The D300°C values, representing the vertical distance from the ignition point (IP) to P300°C (the temperature point at 300 °C farthest from IP), are measured using a compact temperature distribution measurement platform. For MDH/PB, APP + MEL + DPE/PB, and ALHP/PB samples, the respective D300°C values of 145.79 mm, 117.81 mm, and 118.57 mm indicate reductions of 11.11%, 28.17%, and 27.71%, compared to the untreated sample's value of 164.02 mm. The particle boards treated with ALHP, IFR, and MDH demonstrated distinct flame-retardant mechanisms. MDH/PB relied on the thermal decomposition of MDH to produce MgO and H2O for flame retardancy, while APP + MEL + DPE/PB achieved flame retardancy through a cross-linked structure with char expansion, polyphosphate, and pyrophosphate during combustion. On the other hand, ALHP/PB attained flame retardancy by reacting with wood materials and adhesives, forming a stable condensed P-N-C structure. This study serves as a performance reference for the production of cost-effective flame-resistant particleboards and offers a practical method for assessing its fire-resistant properties when used as a decorative finishing material on facades in real fire situations.

Research on Fire-Detection Algorithm for Airplane Cargo Compartment Based on Typical Characteristic Parameters.

To clarify the reasons for inaccurate fire detection in aircraft cargo holds, this article depicts research from the perspective of a single type of sensor detection. In terms of fire smoke, we select dual-wavelength photoelectric smoke sensors for fire-data collection and a genetic algorithm to optimize the classification and detection of random forest fires. From the perspective of fire CO concentration, we use PSO-LSTM to train a CO concentration compensation model to reduce sensor measurement errors. Research is then conducted from the perspective of various types of sensor detection, using the improved BP-AdaBoost algorithm to train a fire-detection model and achieve the high-precision identification of complex environments and fire situations.

UAV-based Forest Fire Exploration and Monitoring System

The goal of this work is to develop a system for monitoring forest fires in real time using an unmanned aerial vehicle (UAV). This study proposes a quadcopter-based forest fire monitoring system based on radio control from a ground station using a geolocation system. This approach ensures the effective use of UAVs both in automatic and manual modes with the help of onboard navigation equipment and controls. The hardware system is built using the ArduPilot controller and various sensors such as GPS, gyro compass, temperature sensor, distance sensor and digital cameras. Flight tests were carried out to assess the accuracy of the positioning system. The results show that the use of UAVs is an effective way to deal with a fire situation in addition to existing methods and technologies for solving operational problems of fire detection.

The Effect of Fire Training Given with Virtual Reality Applications on Individual Awareness

The use of virtual reality applications, which entered our lives with the concept of Industry 4.0, in training contributed to increasing the security awareness of individuals and indirectly to developing security culture studies. Obviously, the maximum efficiency that can be obtained in Occupational Health and Safety studies will occur due to behavioural changes in employees. For this reason, it should be ensured that the safety perceptions of the employees are kept at the highest level with appropriate and continuous training. In recent Occupational Health and Safety studies, the importance of developing technology has caused these studies to evolve in a different direction. The study's main purpose in this context is to evaluate whether the fire training given with virtual reality applications contributes to the development of fire safety skills and raising awareness in individuals. This study aims to reveal the teaching of basic fire safety skills to vocational and technical students and academicians at universities, their fire preparedness and their common behaviour in fire situations by using fire extinguishing systems through virtual reality and fire simulation. In the study, 47 questions including one group pre-test post-test, 31 prepared for the scale and 6 interview questions, one of the experimental methods consisting of 10 multiple-choice questions, the scale and face-to-face interviews were conducted. Participants were able to moderately to completely control events in terms of heredity, adaptation/containment, and sensory attachment; In terms of interface quality, it has been determined that they can control events between none and moderate. There is no significant difference between the presence levels and sub-dimensions of the participants in terms of age factor. It can be said that the training with virtual reality is effective in improving the success of the participants in fire training. After the study, it was determined that 38 out of 40 participants increased their success in fire protection subjects. It will be ensured that the fire training given in Turkey will be given more efficiently and effectively by using technological infrastructures. With the feedback received from this study, the existing virtual reality application improvement and virtual reality applications that are planned to be developed will be studied.

HIGH TEMPERATURE PUSH‐OUT TESTS ON DEMOUNTABLE SHEAR CONNECTORS OF STEEL‐CONCRETE COMPOSITE BEAMS

AbstractThere is no denying that there is a growing need for reusable systems in the construction industry. This is not only a by‐product of the increasing demand of materials, but also a necessity to reduce greenhouse gas emissions associated to the manufacturing process of construction components. Reusable systems aim to solidify the transition from a linear economy model to a circular economy model, where the lifecycle of materials is extended overtime. However, there are several factors that might hinder the reusability of structural components, ranging from regular use over a time period to accidental situations, such as earthquakes and fires.This experimental study focuses its efforts on the analysis of demountable shear connectors for composite structural systems under the influence of high temperatures that resemble a situation of fire. The main idea behind this experimental campaign is to combine a standard push‐out test, where a specimen composed by a HEB‐260 steel profile with reinforced concrete slabs connected to its flanges via high strength bolts is subjected to a vertical force by utilizing a hydraulic jack with a simultaneous thermal action.The tests reproduce a previous experimental campaign performed at the University of Luxembourg (cylinder and coupler systems), but subjected to 4 different temperatures (20, 300, 500 and 600 °C). The loss of strength of the connectors with the temperature, the failure mode and the reusability after a situation of fire are discussed in the present study.

Bioinspired Hierarchical Multi-Protective Membrane for Extreme Environments via Co-Electrospinning-Electrospray Strategy.

Extreme environments can cause severe harm to human health, and even threaten life safety. Lightweight, breathable clothing with multi-protective functions would be of great application value. However, integrating multi-protective functions into nanofibers in a facile way remains a great challenge. Here, a one-step co-electrospinning-electrospray strategy is developed to fabricate a superhydrophobic multi-protective membrane (S-MPM). The water contact angle of S-MPM can reach up to 164.3°. More importantly, S-MPM can resist the skin temperature drop (11.2 °C) or increase (17.2 °C) caused by 0 °C cold or 70 °C hot compared with pure electrospun membrane. In the cold climate (-5 °C), the anti-icing time of the S-MPM is extended by 2.52 times, while the deicing time is only 1.45 s due to the great photothermal effect. In a fire disaster situation, the total heat release and peak heat release rate values of flame retarded S-MPM drop sharply by 24.2% and 69.3%, respectively. The S-MPM will serve as the last line of defense for the human body and has the potential to trigger a revolution in the practical application of next-generation functional clothing.

Self‐Powered Fire Alarm System with Layer‐by‐layer Graphene Oxide/Chitosan Nanocoating of Flame‐Retardant Nanofilms

This study develops a self‐powered fire alarm system that utilizes a sandwich‐like self‐powered fire sensor (SSFS) with a simple system to prevent room fires. The SSFS is small, flame‐retardant, and can be easily installed on furniture or doors. The SSFS uses a nanogenerator constructed by poly(vinylidenefluoride‐co‐trifluoroethylene) (PVDF‐TrFE) nanofibers and a flexible printed circuit board (FPCB) to produce electrical power by harvesting motion energy. This nanogenerator can fully charge capacitors in a few minutes and produces a maximum voltage output of 6.47 V. The SSFS also features two flame‐retardant melamine foams (MFs) coated with graphene oxide (GO) and a chitosan multilayer nanocoating that is fabricated by layer‐by‐layer technology (LBL technology). While encountering a high‐temperature situation, the electrical state of MFs changes from insulated to conductive, triggering the fire alarm light in about four seconds. The sandwich‐like design allows the SSFS to respond to a variety of fire alarm situations, especially in the case where both the top and bottom of the fire alarm sensor are exposed to flame (bilateral fire burning). It is such an innovative research to decrease the delay time of fire‐warning by using this sandwich‐like design fire sensor. The nanogenerator can keep the warning working for 22 s after the initial trigger, which produces enough time to ensure people stay clear of the fire source. All in all, this study presents a novel approach to reducing the risk of building fires through a lightweight and self‐powered fire alarm system that harvests motion energy using piezoelectric nanogenerators (PENGs).

Lateral distortional buckling of continuous composite beams in fire situation: Experimental and numerical analyses

In continuous steel-concrete composite beams, hogging moments may occur near the internal supports. This type of bending causes compression in the bottom flange, which may buckle laterally in an ultimate limit state known as lateral distortional buckling. Despite the consideration that continuity may result in an economic design, no research had yet been conducted on the possibility of lateral distortional buckling in continuous composite beams in fire situation. This paper presents an experimental and numerical study on the lateral distortional buckling of steel concrete composite beams. Four real scale fire tests were conducted and proved that it may indeed occur. A parametric study was also developed. It has been shown that this buckling mode may lead to a reduction in the strength of composite beams of up to 50% when compared to the plastic moment. It was also noted that this buckling mode is usually accompanied by local buckling, which may occur even in compact sections, leading to a decrease in bearing capacity. These results indicate a need of reviewing the design codes to consider the possibility of lateral distortional buckling at high temperatures, as it may be more than at ambient temperature.

Real-time visualization of smoke for fire safety engineering applications

Visibility in smoke is a key aspect in terms of safe egress in various fire related situations. Due to the hazardous nature of fire induced smoke, it is hard to study human behaviour under such conditions, but recent development within the field of virtual reality (VR) has enabled exposure to many different hazardous conditions while remaining relatively safe. However, to obtain valid results from such studies a higher degree of visual realism is often required, therefore when studying effects of visibility, the rendering of smoke needs to be physically based and of high visual fidelity while still being computationally cheap in order to render the virtual environment at high framerates. This paper presents an approach for rendering smoke with a single in-scattering term which allows for smoke and light interaction over multiple wavelengths. The results highlight the importance of smoke characteristics as well as the influence the general lighting conditions can have on perceived visibility. The presented work intends to be of benefit for VR or similar applications where visibility is of key interest.

Fusing Social Media, Remote Sensing, and Fire Dynamics to Track Wildland-Urban Interface Fire

Wildfire is one of the main hazards affecting large areas and causes great damage all over the world, and the rapid development of the wildland-urban interface (WUI) increases the threat of wildfires that have ecological, social, and economic consequences. As one of the most widely used methods for tracking fire, remote sensing can provide valuable information about fires, but it is not always available, and needs to be supplemented by data from other sources. Social media is an emerging but underutilized data source for emergency management, contains a wealth of disaster information, and reflects the public’s real-time witness and feedback to fires. In this paper, we propose a fusion framework of multi-source data analysis, including social media data and remote sensing data, cellphone signaling data, terrain data, and meteorological data to track WUI fires. Using semantic web technology, the framework has been implemented as a Knowledge Base Service and runs on top of WUIFire ontology. WUIFire ontology represents WUI fire–related knowledge and consists of three modules: system, monitoring, and spread, and tracks wildfires happening in WUIs. It provides a basis for tracking and analyzing a WUI fire by fusing multi-source data. To showcase the utility of our approach in a real-world scenario, we take the fire in the Yaji Mountain Scenic Area, Beijing, China, in 2019 as a case study. With object information identified from remote sensing, fire situation information extracted from Weibo, and fire perimeters constructed through fire spread simulation, a knowledge graph is constructed and an analysis using a semantic query is carried out to realize situational awareness and determine countermeasures. The experimental results demonstrate the benefits of using a semantically improved multi-source data fusion framework for tracking WUI fire.

A study on the knowledge-based information system for evacuation situation awareness in the case of fire

This study is on designing a knowledge-based information system for evacuation situation awareness in case of fire. First, in the design of this system, various progress of urban fires was stored and learned in the database so that multiple fire situations could be recognized. In addition, it is to be actively applied to fire disaster prevention through the knowledge-based Fire Dynamics Simulator information system so that it can be actively used for situational information of evacuees and property protection. Moreover, this system is designed to reduce damage to human life and property in the event of a fire in a building, etc. For this purpose, fire extinguishment can be predicted based on building information such as structure and building materials. Natural disasters leading to significant fires can be prevented by predicting fire evolution between buildings. Damage to human life and property due to fire can be contained. This system is a knowledge-based information system that optimizes ubiquitous technologies. It can respond to minimize damage by periodically recognizing the situation of evacuees in case of fire and notifying the central control center of the problem.

Design of mountain fire prevention monitoring system for transmission lines based on machine vision algorithms

Abstract With the continuous development of society, power grid has become a major guarantee for social and economic development, and its coverage is also expanding. The power grid not only covers some developed areas, but also extends to remote mountainous areas with complex changes in geological and climatic conditions. However, at the same time, line failures and power outages caused by mountain fires are becoming increasingly frequent, which poses a significant threat to the safety and stable operation of the power system. Therefore, how to solve the problem of mountain fire on transmission lines has become an important topic today. The main purpose of this study is to achieve effective monitoring of transmission line mountain fires and provide more assurance for the stable operation of the power system. This article discussed the transmission line and traditional mountain fire prevention monitoring system, and combined the current hot machine vision algorithm to design the overall mountain fire prevention monitoring system, focusing on analyzing the differences between this system and traditional systems. Through experiments, it was found that the monitoring accuracy of the mountain fire prevention monitoring system designed in this article has been improved by 10.6 % compared to the traditional system at location 4, 7.6 % at location 6, and 7.9 % at location 7. At the same time, the real-time performance and anti-interference performance of this system were also better than traditional systems, and the overall performance of the system was better. Practice has proved that the system can effectively overcome the interference of external environment, and monitor and identify the fire situation in real time and accurately, ensuring the safety of transmission lines. At the same time, the research on machine vision algorithms in this paper can also help promote the more perfect development of power systems. Practice has proved that this system can effectively overcome the interference of the external environment, and continuously and accurately detect and identify the fire situation.

A Pilot Study to Assess the Feasibility of Comparing Ultra-High Pressure to Low-Pressure Fire Suppression Systems for a Simulated Indirect Exterior Attack

Financial and human resource challenges constrain firefighting in rural communities. This can limit the approaches that can be used in a given residential fire situation. Effective use of portable, lower-cost equipment that would require fewer personnel and less water could greatly benefit rural communities. This study was conducted to assess the feasibility of comparing ultra-high-pressure to low-pressure fire suppression systems at low flow rates. The conditions used simulated an indirect exterior attack through a window. A purpose-built burn room and standardized class A fires were used to compare ultra-high-pressure and low-pressure systems at low flow rates. Temperatures in the burn room were recorded for each condition in triplicate. While neither operating condition resulted in full extinguishment of the fire, the ultra-high-pressure trials saw decreases in the proportion of starting temperature that were faster and of greater magnitude than for the low-pressure trials. This compares with earlier research, simulating a transitional attack that saw similar patterns for temperature cooling but resulted in extinguishment. This preliminary testing provides evidence that the burn container and room, as well as instrumentation and fuel load configurations, are appropriate for more extensive testing of such equipment for exterior fire suppression.

Prediction of maximum ceiling temperature of rectangular fire against wall in longitudinally ventilation tunnels: Experimental analysis and machine learning modeling

In this work, experimental analysis and machine learning modeling of maximum ceiling temperature for wall fire in longitudinally ventilation tunnels were conducted. The results indicate that the maximum ceiling temperature is restrained by the longitudinal ventilation, and the maximum ceiling temperature induced by a free fire is significantly lower than that of a wall fire. The aspect ratio of the burner has an impact on the maximum ceiling temperature. The larger the aspect ratio of the burner, the higher the maximum temperature. Based on the “mirror” assumption, the difference in maximum ceiling temperature caused by the changes in entrainment characteristics between wall fires and free fires can be explained. The influence of longitudinal wind inertia forces on the aspect ratio of the burner was analyzed. It was found that when the aspect ratio was large, it is affected by the smaller longitudinal wind inertia force to generate a higher flame height, and this will lead to higher maximum ceiling temperatures. The classical model cannot explain the difference in maximum ceiling temperature between wall fires and free fires, as well as the effect of aspect ratio on the maximum ceiling temperature. Further explanation and verification were conducted by combining the temperature field and the flow field. In addition, genetic algorithms were applied to compensate for the shortcomings of back propagation neural networks in randomly generating initial weights and initial biases. A new model-free calculation (GA-BPNN) model was proposed to predict the maximum ceiling temperature in a ventilation tunnel. Experimental results were compared with the predicted results, and error analysis was conducted on the data from the training and testing sets, with a relative error within ±20%. The GA-BPNN algorithm proved to be a promising method that can provide direct guidance for the experimental analysis and the determination of relevant parameters in the fire situation analysis.