Fire Technology最新文献

{"title":"Numerical Studies and Practical Design Suggestions on Fire Resistance of Unprotected High-Strength Steel Extended End-Plate Connections","authors":"Weiyong Wang,&nbsp;Zhihao Chen,&nbsp;Linbo Zhang","doi":"10.1007/s10694-023-01397-5","DOIUrl":"10.1007/s10694-023-01397-5","url":null,"abstract":"<div><p>The material properties of high-strength steels deteriorate under fire conditions and depends on the temperature and fire duration. As a time-dependent inelastic strain behavior, the thermal creep effect becomes significant at elevated temperatures and influences the fire resistance of connections. This paper presents numerical studies on the fire response of unprotected extended end-plate connections made of high-strength steels (Q460, Q690 and Q960), explicitly considering the creep effect. Transient state finite element models including or excluding creep were developed using ABAQUS and validated against the experimental results under the restrained sub-framework. The numerical analysis results exhibit a better agreement with the experimental results regarding the deformation ability and failure mode if the creep effect is considered. Thus, creep is a non-negligible effect in investigating the fire performance of end-plate joints. Parametric studies were carried out to quantitatively assess the influence of moment ratio of connection, axial pressure ratio of column, end-plate thickness and heating rates on rotation–time–temperature characteristics and stress distribution. The numerical results show that the magnitudes of bending moment applied on the connection and axial load on the column play crucial roles in evaluating the fire endurance and critical temperatures. However, the effect of end-plate thickness on the fire-structural behavior of extended end-plate connections is negligible. The heating rate has little effect on the critical temperatures of connections. The rotation capacity of high-strength steel extended end-plate connections depends on the failure mode to a large extent. Finally, fire resistance design suggestions for high-strength steel end-plate connections were put forward according to the observations on the parametric studies.</p></div>","PeriodicalId":558,"journal":{"name":"Fire Technology","volume":"59 4","pages":"1585 - 1612"},"PeriodicalIF":3.4,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4939859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automating Fire Detection and Suppression with Computer Vision: A Multi-Layered Filtering Approach to Enhanced Fire Safety and Rapid Response","authors":"Md Safwan Mondal,&nbsp;Varun Prasad,&nbsp;Ramendra Kumar,&nbsp;Nilendu Saha,&nbsp;Saumadeep Guha,&nbsp;Ratna Ghosh,&nbsp;Achintya Mukhopadhyay,&nbsp;Sourav Sarkar","doi":"10.1007/s10694-023-01392-w","DOIUrl":"10.1007/s10694-023-01392-w","url":null,"abstract":"<div><p>A computer vision-based integrated fire detection and automated suppression device capable of real-time functioning is proposed to enhance the fire safety. The developed multilayered algorithm considers color based clue detection and thereafter incorporates three filtration stages ‘Centroid Analysis’, ‘Histogram Analysis’ and ‘Variance Analysis’ for successful fire detection. Results from the proposed algorithm has been compared and validated against standard video datasets and was found to have an overall accuracy of 95.26% with 91.61% true positive detection rate, only 8.39% of false detection in positive fire videos and true negative rate of 98.91% with only 1.09% of false detection in negative nonfire videos. Additionally, our algorithm showed an average improvement of 7.95% in accuracy and 9.43% in precision over existing algorithms, demonstrating its sensitivity and reliability for effective fire detection and suppression. The algorithm also includes unique fire localization techniques to locate the detected fire, which was integrated with an Arduino based suppression unit to provide a real- time autonomous fire suppression. Laboratory-scale experimental validation has shown practical significance of the proposed system for any kind of personal, industrial, indoor, or outdoor environmental applications with a high precision value of 99.51% and a recall value of 95.93%.\u0000</p></div>","PeriodicalId":558,"journal":{"name":"Fire Technology","volume":"59 4","pages":"1555 - 1583"},"PeriodicalIF":3.4,"publicationDate":"2023-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10694-023-01392-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4868160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heat Transfer in Ultra-High-Performance Concrete-Filled Double-Skin Tubes Under Fire Conditions","authors":"A. H. A. Abdelrahman,&nbsp;Mohamed Ghannam,&nbsp;Sameh Lotfy,&nbsp;Mohammad AlHamaydeh","doi":"10.1007/s10694-023-01386-8","DOIUrl":"10.1007/s10694-023-01386-8","url":null,"abstract":"<div><p>This paper develops an FEA modeling protocol for simulating ultra-high-performance concrete-filled double-skin tubes (CFDST) for heat transfer analysis purposes. The research presented in this paper refines the existing FE methodologies for circular, rectangular, elliptical, hexagonal, and octagonal CFDST members under fire conditions. Various modeling parameters, such as thermal properties of different materials and the thermal contact conductance at the interaction surfaces, are incorporated and controlled via an automatic algorithm for proficient modeling. It is found that the available models for calculating the thermal contact conductance at the interfaces between metal tubes and the concrete cores have a strong dependence on the cross-sectional shape. Thus, a refined model of the thermal conductance for the hexagonal and octagonal CFDST columns is proposed. Extensive experimental results (212 fire tests) are assembled from the literature to verify the proposed FE methodology. Good agreements with test results are demonstrated when predicting the temperature fields within the considered CFDST cross-sections. Consequently, extensive results from the proposed algorithm can provide an initial basis for parametric studies and for forthcoming nonlinear stress analysis simulations of CFDST columns under fire, which are primary goals in future studies. Finally, complying with the existing design codes, a new simplified analytical model based on the finite difference (FD) method is presented for predicting the temperature developments through CFDST columns.</p></div>","PeriodicalId":558,"journal":{"name":"Fire Technology","volume":"59 4","pages":"1519 - 1554"},"PeriodicalIF":3.4,"publicationDate":"2023-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10694-023-01386-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4730493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Simulations of Gas Burner Experiments in a Residential Structure with HVAC System","authors":"Dushyant M. Chaudhari,&nbsp;Craig Weinschenk,&nbsp;Jason E. Floyd","doi":"10.1007/s10694-023-01390-y","DOIUrl":"10.1007/s10694-023-01390-y","url":null,"abstract":"<div><p>Controlled fire experiments using a gas burner were previously conducted in a purpose-built, two-story, moderately air-tight residential structure to understand the effect of a heating, ventilating, and air conditioning (HVAC) system and door positions on the fire-induced environment. Temperatures, gas concentrations (oxygen, water vapor, carbon dioxide), and differential pressures were monitored throughout the structure. HVAC status (off vs. on) and stairwell door position of the fire room (open vs. closed) were varied for the experiments analyzed in this paper. In this study, Fire Dynamics Simulator (FDS) v. 6.7.9 was used to simulate these experiments. Experimental data quantifying the air tightness of the building and cold flowrates through HVAC vents were determined to be important to optimize leakages and HVAC loss coefficients for the simulation setup. Pressure development in the structure was predicted correctly to be higher on the first floor and lower in the basement, but the magnitude of steady-state pressure was underpredicted. The measured and predicted steady-state temperature distributions were statistically different for the cases with and without the HVAC on, regardless of the door position. FDS predicted gas transport through the HVAC duct network, and under-predicted temperature rise and water vapor content by about 9% and 10%, respectively, and over-predicted volumetric oxygen and carbon dioxide content by about 21% and 6%, respectively. Temperature rise prediction in the closed room, where the gas transport primarily occurred via the HVAC duct network, improved after including heat loss from the HVAC duct to the ambient.</p></div>","PeriodicalId":558,"journal":{"name":"Fire Technology","volume":"59 4","pages":"1489 - 1517"},"PeriodicalIF":3.4,"publicationDate":"2023-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10694-023-01390-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4982939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Full-Scale Experimental Study on the Integrity of Tempered Glass Protected by Different Sprinkler Systems in High-Rise Building Fire","authors":"Dong Wang,&nbsp;Xiaoyu Ju,&nbsp;Jia Gui,&nbsp;Yaqiang Jiang,&nbsp;Zhizuan Zhou,&nbsp;Xiaodong Zhou,&nbsp;Junjun Liu,&nbsp;Lizhong Yang","doi":"10.1007/s10694-023-01393-9","DOIUrl":"10.1007/s10694-023-01393-9","url":null,"abstract":"<div><p>Tempered glass is a building material often used in curtain walls and windows of high-rise buildings. Tempered glass is easily damaged by high temperature and thermal radiation in a fire, creating a channel for flame spread. The breakage mechanism of glass is rarely studied under the protection of different sprinkler system. Therefore, three sprinkler systems were used to observe their protection effect on tempered glass at different operating pressures and layouts in a full-scale (5 m (length) × 4.5 m (width) × 3.2 m (height)) compartment fire. The square pool of 1 m² was used as the fire source, and the fuel was n-heptane. The results show that glass is not only heated by smoke, but may also directly contact with flames. There are two thermal breakage mechanisms for window glass under different protection conditions. The sprinkler system significantly reduces the temperature outside the window even if the glass cracks or bursts. The interaction of the glass boundary and the water flow trajectory has a decisive influence on the final protection effect in addition to the three key factors including the sprinkler type, operating pressure and layout. This research provides a mature and reliable tempered glass protection scheme for relevant designers.</p></div>","PeriodicalId":558,"journal":{"name":"Fire Technology","volume":"59 4","pages":"1465 - 1488"},"PeriodicalIF":3.4,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4617076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigations on Self-extinction of Incense Sticks","authors":"A. Ve. Sowriraajan,&nbsp;A. Shivakumar,&nbsp;Sachin Payyanad,&nbsp;C. S. Bhaskar Dixit,&nbsp;H. S. Mukunda","doi":"10.1007/s10694-023-01389-5","DOIUrl":"10.1007/s10694-023-01389-5","url":null,"abstract":"<div><p>A low-probability but serious self-extinction of smouldering incense sticks is an undesirable characteristic. This paper reports the investigations on its cause and remedy, conducted for an incense stick manufacturer. Measurement of smouldering rate and surface temperature of glowing incense stick tip of several known compositions were made by recording the time required for the propagation of smoldering front and using thermal camera respectively. Several possible explanations like presence of (a) phosphorous, potassium, and sodium related compounds, (b) inadvertent inclusion of inorganic compounds, and others ruled out the role of phosphorous and related compounds, and a simple role of inorganic compounds despite the fact that defective incense sticks invariably contained large fraction of silica (SiO₂) as revealed by scanning electron microscopy/ energy dispersive X-ray diffraction (SEM/EDX). Ultimately the issue was traced to the presence of antigorite that must have got infused into the incense sticks through termite mud into the raw materials. X-ray diffraction (XRD) of incense stick samples confirmed silica is in the form of α-quartz associated with antigorite in all defective samples and also in termite mud infested sample. Thermal studies of the incense sticks using differential thermal analysis (DTA) show endothermic decomposition of defective samples at 550 to 580°C and is also confirmed through differential scanning calorimetry (DSC) which shows an endothermic peak around 576°C corresponding to the endothermic phase transformation temperature of antigorite. It is therefore inferred that the presence of materials like antigorite in combination with α-quartz in incense sticks produce significant endothermal decomposition leading to self-extinction. The primary practical cause has been traced to termite mud infusion into the raw materials used for making the incense sticks.\u0000</p></div>","PeriodicalId":558,"journal":{"name":"Fire Technology","volume":"59 4","pages":"1449 - 1464"},"PeriodicalIF":3.4,"publicationDate":"2023-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4425166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Method of Simulating Creep Buckling Behaviour of Steel Columns at Elevated Temperatures","authors":"Linbo Zhang,&nbsp;Lei Xu,&nbsp;Weiyong Wang","doi":"10.1007/s10694-023-01385-9","DOIUrl":"10.1007/s10694-023-01385-9","url":null,"abstract":"<div><p>When subjected to a constant applied load and elevated temperature, structural steel columns may buckle after a certain duration due to increasing creep-induced deformation, and such mode of failure is referred to as creep buckling. This paper presents an analytical method to simulate the creep buckling behaviour of steel columns at elevated temperatures by incorporating the Fields-and-Fields creep model and a nonlinear constitutive model of steel at elevated temperatures. Fire and creep buckling tests on Q690 high-strength steel columns are selected to validate the proposed method, and a good agreement between the experimental and analytical results is achieved. This demonstrates that the proposed method can provide an accurate assessment of the lateral deflection of steel columns at elevated temperatures accounting for the creep effect. Time- and strain-hardening formulations are separately incorporated into the analysis. The obtained results indicate that the strain-hardening formulation is more suitable for cases with stress variations. The study also unveils the failure mechanism of creep buckling, which indicates that the creep-induced lateral deflection of an axially loaded steel column at elevated temperatures is initiated by the gradient of stress and strain distributions on the cross-section of the column triggered by the initial imperfection. The parametric study results show that the creep buckling time of the steel column decreases as the load ratio, elevated temperature, and initial imperfection increase; however, the creep buckling time increases as the slenderness ratio increases.</p></div>","PeriodicalId":558,"journal":{"name":"Fire Technology","volume":"59 4","pages":"1421 - 1448"},"PeriodicalIF":3.4,"publicationDate":"2023-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4308613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Study on Combustion Characteristics of Electrolytes and Slurries for Semi-Solid Lithium-ion Flow Battery","authors":"Yuhang Hu,&nbsp;Siyuan Cheng,&nbsp;Pengjie Liu,&nbsp;Jiaqing Zhang,&nbsp;Qiangling Duan,&nbsp;Huahua Xiao,&nbsp;Jinhua Sun,&nbsp;Qingsong Wang","doi":"10.1007/s10694-023-01384-w","DOIUrl":"10.1007/s10694-023-01384-w","url":null,"abstract":"<div><p>Semi-solid lithium-ion flow battery (SSLFB) is a promising candidate in the field of large-scale energy storage. However, as a key component of SSLFB, the slurry presents a great fire hazard due to the extremely flammable electrolyte content in the slurry as high as 70 wt%–95 wt%. To evaluate the fire risk of SSFLB, the combustion experiments of electrolyte and slurry were conducted using cone calorimeter, and the critical fire parameters such as heat release rate (HRR), mass loss rate (MLR), and gas production were analyzed. This study firstly compared the combustion characteristics of electrolytes with the addition of different lithium salts (LiPF₆ and LiTFSI). The results showed that the peak HRR (pHRR) and peak MLR (pMLR) of LiTFSI-based electrolyte were reduced by 30.3% and 33.2%, respectively, compared with LiPF₆-based electrolyte. Also, LiTFSI-based electrolyte possessed a relatively lower toxic hazard. Overall, LiTFSI could reduce the fire hazard of the electrolyte compared with LiPF₆. Then, the combustion behaviour of slurries containing different electrode materials (Li₄Ti₅O₁₂, LiNi_0.8Co_0.1Mn_0.1O₂, LiFePO₄, and Graphite) was investigated. It was observed that the splashing occurred in the early stage combustion of slurries. The splashing of S-LTO and S-LFP was relatively violent, while only sporadic splashing occurred for S-NCM and S-graphite. Based on the pHRR and pMLR test results, the order of fire risk of the four slurries is determined as S-LTO &gt; S-LFP &gt; S-NCM &gt; S-Graphite. The pHRR and pMLR of slurries other than S-LTO are lower than that of electrolyte, thus their fire risk is lower than electrolyte. The results of this study can provide a reference for the fire hazard evaluation and safety improvement of the SSFLB system.</p></div>","PeriodicalId":558,"journal":{"name":"Fire Technology","volume":"59 3","pages":"1199 - 1220"},"PeriodicalIF":3.4,"publicationDate":"2023-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10694-023-01384-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4266111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating Numerically the Effect of Wind on Fire Spread Between Two Informal Settlements Dwellings","authors":"M. Beshir, M. Mohamed, S. A. Kouritem, C. Lemmertz, F. Centeno, David Rush","doi":"10.1007/s10694-023-01374-y","DOIUrl":"https://doi.org/10.1007/s10694-023-01374-y","url":null,"abstract":"","PeriodicalId":558,"journal":{"name":"Fire Technology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44011317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Sensitivity Study of a Thermal Propagation Model in an Automotive Battery Module","authors":"Chen Huang,&nbsp;Roeland Bisschop,&nbsp;Johan Anderson","doi":"10.1007/s10694-023-01383-x","DOIUrl":"10.1007/s10694-023-01383-x","url":null,"abstract":"<div><p>Thermal runaway is a major concern for lithium-ion batteries in electric vehicles. A manufacturing fault or unusual operating conditions may lead to this event. Starting from a single battery cell, more cells may be triggered into thermal runaway, and the battery pack may be destroyed. To prevent this from happening, safety solutions need to be evaluated. Physical testing is an effective, yet costly, method to assessing battery safety performance. As such, the potential of a numerical tool, which can cut costs and reduce product development times, is investigated in terms of capturing a battery module’s tolerance to a single cell failure. A 3D-FE model of a battery module was built, using a commercial software, to study thermal runaway propagation. The model assumes that when the cell jelly roll reaches a critical value, thermal runaway occurs. This approach was considered to study the module’s tolerance to a single cell failure, which was in reasonable agreement with what had been observed in full-scale experiments. In addition, quantitative sensitivity study on the i) model input parameters, ii) model space, and iii) time resolutions on the computed start time instant and time duration of thermal runaway were performed. The critical temperature was found to have the greatest influence on thermal runaway propagation. The specific heat capacity of jelly roll was found to significantly impact the thermal runaway time duration. The multi-physics model for battery thermal propagation is promising and worth to be applied with care for designing safer batteries in combination with physical testing.</p></div>","PeriodicalId":558,"journal":{"name":"Fire Technology","volume":"59 4","pages":"1405 - 1420"},"PeriodicalIF":3.4,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10694-023-01383-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4175972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}