Improvement of fire door design using experimental and numerical modelling investigations

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohamed A. Khalifa ◽  
Mohamed A. Aziz ◽  
Mohamed Hamza ◽  
Saber Abdo ◽  
Osama A. Gaheen
Keyword(s):  
Cross Sections ◽  
Mechanical Response ◽  
Practical Implication ◽  
Fem Analysis ◽  
Positive Pressure ◽  
Pressurized Water ◽  
Content Type ◽  
Standard Fire ◽  
Minimum Deformation ◽  
Fire Door

PurposeFire door should withstand a high temperature without deforming. In the current paper, the challenges of improving the behaviour of the conventional fire door were described using various internal stiffeners in pair swinging-type fire door.Design/methodology/approachThe temperature distribution on the outside door surface was measured with distributed eight thermocouples. Subsequently the internal side was cooled with pressurized water hose jet stream of 4 bar. The transient simulation for the thermal and structure analysis was conducted using finite element modelling (FEM) with ANSYS 19. The selected cross sections during numerical simulation were double S, double C and hat omega stiffeners applied to 2.2 m and 3 m door length.FindingsDuring the FEM analysis, the maximum deformations were 7.2028, 5.4299, 5.023 cm for double S, double C and hat omega stiffeners for 2.2 m door length and 6.57, 4.26, 2.1094 cm for double S, double C and hat omega stiffeners for 3 m door length. Finally, hat omega gives more than three times reduction in the deformation of door compared to double S stiffeners which provided a reference data to the manufacturers.Research limitations/implicationsThe research limitation included the limited number of fire door tests due to the high cost of single test, and the research implication was to achieve an optimal study in fire door design.Practical implicationsAchieving the optimum design for the internal door stiffeners where the hat omega stiffener gives minimum door deformation compared to the other stiffeners was considered the practical implication. The work included two experimental fire door tests according to the standard fire test (ANSI/UL 10C – Positive Pressure of Fire Tests of Door Assemblies) for a door of 2.2 m length with double S stiffeners and a door of 3 m length with hat omega stiffeners, which achieved minimum deformation.Originality/valueThe behavior and mechanical response of door leaf were improved through using internal hat omega stiffeners under fire testing. This study was achieved using FEM in ANSYS 19 for six cases of different lengths and stiffeners for fire doors. The simulation model showed a very close agreement with the experimental results with an error of 0.651% for double S and 1.888% for hat omega.

ANN prediction of fire temperature in timber

2019 ◽  
Vol 10 (2) ◽  
pp. 233-244
Author(s):  
Paulo Cachim
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Design Methodology ◽  
Content Type ◽  
Construction Engineering ◽  
Standard Fire ◽  
Model Complex ◽  
Engineering Problems ◽  
The Cross ◽  
Fire Loading

Purpose Fire degradation is an extremely important risk that threatens timber structures. It is therefore normal that timber design codes include provisions for the design and verification of structures under fire loading. Eurocode 5 is no exception to this, but the simplified methods presented in the code show some inconsistencies, and the advanced method is not practical to use for design purposes. Artificial neural networks (ANNs) have the ability to model complex problems and have been used in a variety of construction engineering problems. They can learn from a subset of data, and then they can be used to predict the results for other input parameters. The purpose of this study is to present the possibility of the use of ANNs for the prediction of temperatures in rectangular timber cross sections, under fire exposure. Design/methodology/approach In this work, a multilayer feedforward ANN has been trained to predict the temperatures within a timber cross section, using as input the size of the cross section, the timber density, the time of exposure and the coordinates of the point within the cross section. Findings The results obtained clearly indicate that ANN can be used to predict the temperatures in a timber cross section subjected to fire. Originality/value ANNs have not been used for the prediction of temperatures in timber cross sections. The use of ANN makes the temperature prediction under a standard fire loading in a cross section extremely easy to implement in any code. These results can be used to calculate the strength of the elements after fire.

scholarly journals Creating products in the absence of markets: a robust design approach

2008 ◽  
Vol 19 (3) ◽  
pp. 407-420 ◽  
Author(s):  
Philippe Silberzahn ◽  
Christophe Midler
Keyword(s):  
Longitudinal Study ◽  
Product Design ◽  
Robust Design ◽  
Practical Implication ◽  
Collaborative Work ◽  
High Tech ◽  
Content Type ◽  
Exploration Process ◽  
Strategic Process ◽  
Alternative Approach

PurposeThe purpose of this study is to examine how firms deal with a situation of true uncertainty about their potential markets and technologies. Specifically, it asks how firms can create products when the corresponding market does not exist.Design/methodology/approachThis paper is based on a longitudinal study of a high‐tech firm, combined with analysis of existing theory in product design and entrepreneurship.FindingsMarkets and products are usually a defining choice made early on by firms in their strategic process. Such a choice guides their development by providing a “stable concept” to which decisions can be related. When markets do not exist yet, however, this approach is not effective. Early choice of products and markets limits firms' flexibility by constraining their ability and willingness to adapt, while fundamental new technical and market information is likely to emerge during the project that will prove the initial assumptions wrong. The paper shows an alternative approach where products and markets actually result from a generic process of products and markets exploration driven by the firm. It is suggested that this approach forms a robust design in that it allows the firm to deal with the uncertainty by simultaneously developing its products and exploring markets, while preserving the flexibility to adapt to the changing environment.Practical implicationsThe practical implication of this paper is to suggest an alternative approach to deliberate planning in high‐tech ventures. With this approach, rather than markets and products, strategy defines a market and technology exploration process.Originality/valueThe paper is original in three ways. It links the product design and market exploration processes in high‐tech firm development; it is based on an in‐depth longitudinal study; and it results from an academic‐practitioner collaborative work.

scholarly journals “Happy slaves”? The adaptation problem and identity politics in the writings of Amartya Sen

2016 ◽  
Vol 43 (12) ◽  
pp. 1178-1193
Author(s):  
Tony Burns
Keyword(s):  
Identity Politics ◽  
Design Methodology ◽  
Conceptual Analysis ◽  
Practical Implication ◽  
Methodological Approach ◽  
Mary Wollstonecraft ◽  
Amartya Sen ◽  
Content Type ◽  
The Relationship ◽  
Practical Implications

Purpose The purpose of this paper is to examine the relationship between Amartya Sen’s notion of adaptation and his views on identity politics by focussing on the issue of slavery and, more specifically, on the example of the happy or contented slave. Design/methodology/approach The paper is text based. The methodological approach adopted is that of conceptual analysis, as is typical for work of this kind. Findings The paper concludes that the example of the happy or contented slave is indeed a fruitful one for those interested in exploring the relationship between Sen’s views on “the adaptation problem” and his views on identity politics, especially in relation to the subjection of women. Here Sen’s debt to the ideas of Mary Wollstonecraft and John Stuart Mill is particularly important. Research limitations/implications One implication of the argument of the paper is that there is a need to consider more carefully the differences that exist between the views of Wollstonecraft and Mill, so far as the example of the happy or contented slave is concerned. Practical implications One practical implication of the paper is that, hopefully, it establishes the continued relevance of the ideas of thinkers such as Wollstonecraft and Mill today, not least because of the influence that they have had on theoreticians such as Amartya Sen. Social implications The paper addresses issues which are of considerable social and political significance, especially for women in underdeveloped societies today. Originality/value The example of the happy or contented slave has not received much discussion in the literature on Sen, although Sen himself has suggested that the distinction between happiness and contentment is an important one, which does merit further discussion.

Numerical Analysis of Branch Mechanical Response to Loading

2019 ◽  
Vol 45 (4) ◽  
Author(s):  
Barbora Vojáčková ◽  
Jan Tippner ◽  
Petr Horáček ◽  
Luděk Praus ◽  
Václav Sebera ◽  
...  
Keyword(s):  
Finite Element ◽  
Cross Sections ◽  
Mechanical Response ◽  
Mechanical Analysis ◽  
Beam Deflection ◽  
Design System ◽  
Elliptical Cross ◽  
Static Mechanical ◽  
The Difference ◽  
Tree Uprooting

Failure of a tree can be caused by a stem breakage, tree uprooting, or branch failure. While the pulling test is used for assessing the first two cases, there is no device-supported method to assess branch failure. A combination of the optical technique, pulling test, and deflection curve analysis could provide a device-supported tool for this kind of assessment. The aim of the work was to perform a structural analysis of branch response to static mechanical loading. The analyses were carried out by finite element simulations in ANSYS using beam tapered elements of elliptical cross-sections. The numerical analyses were verified by the pulling test combined with a sophisticated optical assessment of deflection evaluation. The Probabilistic Design System was used to find the parameters that influence branch mechanical response to loading considering the use of cantilever beam deflection for stability analysis. The difference in the branch’s deflection between the simulation and the experiment is 0.5% to 26%. The high variability may be explained by the variable modulus of the elasticity of branches. The finite element (FE) sensitivity analysis showed a higher significance of geometry parameters (diameter, length, tapering, elliptical cross-section) than material properties (elastic moduli). The anchorage rotation was found to be significant, implying that this parameter may affect the outcome in mechanical analysis of branch behavior. The branch anchorage can influence the deflection of the whole branch, which should be considered in stability assessment.

Experimental study on fire resistance of a full-scale composite floor assembly in a two-story steel framed building

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lisa Choe ◽  
Selvarajah Ramesh ◽  
Xu Dai ◽  
Matthew Hoehler ◽  
Matthew Bundy
Keyword(s):  
Natural Gas ◽  
Fire Resistance ◽  
Full Scale ◽  
System Level ◽  
Compartment Fire ◽  
Content Type ◽  
Standard Fire ◽  
Fire Experiment ◽  
The Usa ◽  
Floor System

PurposeThe purpose of this paper is to report the first of four planned fire experiments on the 9.1 × 6.1 m steel composite floor assembly as part of the two-story steel framed building constructed at the National Fire Research Laboratory.Design/methodology/approachThe fire experiment was aimed to quantify the fire resistance and behavior of full-scale steel–concrete composite floor systems commonly built in the USA. The test floor assembly, designed and constructed for the 2-h fire resistance rating, was tested to failure under a natural gas fueled compartment fire and simultaneously applied mechanical loads.FindingsAlthough the protected steel beams and girders achieved matching or superior performance compared to the prescribed limits of temperatures and displacements used in standard fire testing, the composite slab developed a central breach approximately at a half of the specified rating period. A minimum area of the shrinkage reinforcement (60 mm2/m) currently permitted in the US construction practice may be insufficient to maintain structural integrity of a full-scale composite floor system under the 2-h standard fire exposure.Originality/valueThis work was the first-of-kind fire experiment conducted in the USA to study the full system-level structural performance of a composite floor system subjected to compartment fire using natural gas as fuel to mimic a standard fire environment.

scholarly journals Analysis of the drivers and benefits of BIM incorporation into quantity surveying profession

2018 ◽  
Vol 16 (5) ◽  
pp. 750-766 ◽  
Author(s):  
Solomon Olusola Babatunde ◽  
Damilola Ekundayo ◽  
Olubola Babalola ◽  
Jumoke Aduramigba Jimoh
Keyword(s):  
Undergraduate Students ◽  
Practical Implication ◽  
Empirical Studies ◽  
Information Modeling ◽  
Content Type ◽  
Whitney Test ◽  
Mann Whitney Test ◽  
Significant Difference ◽  
Building Information ◽  
Quantity Surveying

Purpose Building information modeling (BIM) inclusion in education pedagogy is crucial in preparing skilled graduates for employment in the construction industry. Against this backdrop, studies on BIM education abound in architecture, engineering and construction (AEC) programmes in higher education institutions (HEIs). However, there are limited empirical studies on BIM potentials in the quantity surveying (QS) profession in HEIs, particularly in developing countries. The purpose of this study is to identify and assess the BIM drivers and benefits as important to the QS profession using an empirical approach. Design/methodology/approach A comprehensive literature review was conducted to identify the BIM drivers and benefits in relation to the QS profession, which was used to design a questionnaire. To capture a broad perception, a questionnaire survey was carried out which targeted the academia and final year undergraduate students from two selected universities offering QS honour degree programmes in Nigeria. Data collected were analysed using mean score, standard deviation and Mann–Whitney test. Findings The study identified 12 BIM drivers in relation to the QS profession and the analysis of the ranking revealed that almost all the identified BIM drivers are considered by respondents as important. The study further identified 14 BIM benefits and the analysis of the ranking indicated that all the identified BIM benefits are considered as important. The results of the Mann–Whitney test indicated a slight statistically significant difference, particularly in one of the selected universities on the ranking of the BIM drivers and benefits as important to the QS profession. Practical implication The findings of the study provide empirical evidence on the current perceptions of the drivers and benefits of BIM to QS academia and students as they explore the concept for the advancement of QS profession. Originality/value This study would provide practical insights to use BIM for QS practice. Also, this study would contribute to improving the QS graduates and professional quantity surveyors understanding of the BIM knowledge applicable to QS profession.

Printing with mechanically interlocked extrudates using a custom bi-extruder for fused deposition modelling

2018 ◽  
Vol 24 (6) ◽  
pp. 921-934 ◽  
Author(s):  
Mohammad Abu Hasan Khondoker ◽  
Asad Asad ◽  
Dan Sameoto
Keyword(s):  
Cross Sections ◽  
Acrylonitrile Butadiene Styrene ◽  
Easy Access ◽  
Fused Deposition Modelling ◽  
Content Type ◽  
Immiscible Polymers ◽  
Fused Deposition ◽  
Functionally Gradient ◽  
Different Sources ◽  
Butadiene Styrene

Purpose This paper aims to target to print functionally gradient materials (FGM) devices made of immiscible polymers in multi-material fused deposition modelling (FDM) systems. The design is intended to improve adhesion of dissimilar thermoplastics without the need for chemical compatibilization so that filaments from many different sources can be used effectively. Therefore, there is a need to invent an alternative solution for printing multiple immiscible polymers in an FDM system with the desired adhesion. Design/methodology/approach In this study, the authors have developed a bi-extruder for FDM systems which can print two thermoplastics through a single nozzle with a static intermixer to enhance bonding between input materials. The system can also change the composition of extrudates continuously. Findings The uniqueness of this extruder is in its easy access to the internal channel so that a static intermixer can be inserted, enabling deposition of mechanically interlocked extrudates composed of two immiscible polymers. Without this intermixer, the bi-extruder extrudes with simple side-by-side co-extrusion having no mechanical interlocking. The bi-extruder was characterized by printing objects using pairs of materials including polylactic acid, acrylonitrile butadiene styrene and high impact polystyrene. Microscope images of the cross-sections of the extrudates confirm the ability of this bi-extruder to control the composition as desired. It was also found that the mechanically interlocked extrudates composed of two immiscible polymers substantially reduces adhesion failures within and between filaments. Originality/value In this study, the first-ever FDM extruder with a mechanical blending feature next to the nozzle has been designed and used to successfully print FGM objects with improved mechanical properties.

Judicial corruption: the case of Nigeria

2018 ◽  
Vol 25 (4) ◽  
pp. 926-939
Author(s):  
Vasudev Das
Keyword(s):  
Practical Implication ◽  
Self Control ◽  
Reasonable Doubt ◽  
Social Implication ◽  
Content Type ◽  
Judicial Corruption ◽  
Causative Factors ◽  
Study Results ◽  
Low Self Control

Purpose The purpose of this paper is to diagnostically explore the phenomenon of judicial corruption in Nigeria, its causative factors and generate strategies such as sonic therapeutic intervention, among others, that would facilitate an amelioration of the situation. The judiciary which is supposed to be last hope of justice for the Nigerian citizenry has been proven beyond reasonable doubt to have been infected with the virus of corruption, and therefore, an urgent call for action to rectify the situation is imperative. Design/methodology/approach The study uses a qualitative approach rooted in case study tradition. Findings The findings showed that power and testosterone, cheating proclivity, family pressure, qualitative passion and ignorance, low self-control, inordinate kleptocratic desire, unrestrained mind and sensory modalities, phenomenological mindset and identity crisis as endogenous contributive factors of judicial corruption in Nigeria. Research limitations/implications The limitation of the study stemmed from the fact that inasmuch as a perception of corruption and corruption are cultural phenomena, the study results cannot be generalizable. Practical implications The practical implication of the research is rooted in the fact that the Nigerian judiciary can gain from the study results and recommendation(s) if implemented without fear or favor for the overall renewal of the judiciary and the nation at large. Social implications The study is geared toward ameliorating the Nigerian corrupt judiciary or repositioning the judiciary on its pivotal dignity, and hence, its social implication cannot be overemphasized inasmuch as a positive social change would prevail if the study results and recommendation(s) are aligned with and implemented. Originality/value Inquiry on judicial corruption through the lens of qualitative research with Nigeria as a case study is highly understudied, and hence, this research fills the gap in the financial crime literature.

Under-promising and over-delivering: pleasing the customer or strategic blunder?

2017 ◽  
Vol 31 (7) ◽  
pp. 720-732 ◽  
Author(s):  
Omer Topaloglu ◽  
David E. Fleming
Keyword(s):  
Practical Implication ◽  
Business Environment ◽  
Empirical Examination ◽  
Content Type ◽  
Expectation Management ◽  
New Perspective ◽  
The Individual ◽  
Service Expectation ◽  
The Relationship ◽  
Promise Keeping

Purpose The paper aims to provide a theoretical and empirical examination of the relationship between service expectation management, expectation inducing agent and customer satisfaction. Design/methodology/approach Based on the disconfirmation paradigm in services and the promise-keeping premise in psychology, the hypotheses are developed and empirically tested using three experiments that manipulated expectations, expectation inducing agent and service outcome. Findings The findings provide reconciliation to the previous studies in services and show that effectiveness of expectation management strategy depends on the individual expectation thresholds and the expectation inducing agent. If customers patronize a firm expecting more, then over-delivering on the service promise results in a significant benefit. However, for those customers whose mental expectation threshold is exceeded, keeping promises is as effective as exceeding promises. Practical implications The practical implication of this paper is that services managers should be cognizant of the mental expectation threshold of customers and be wise in utilizing the under-promise, over-deliver strategy. Originality/value Using a threshold approach, this paper introduces a new perspective to service practitioners who are trying to manage expectations in a highly variable business environment. It also benefits service researchers who are trying to enhance the understanding of service expectation management.

Building entrepreneurial capacity in rural areas

2017 ◽  
Vol 23 (6) ◽  
pp. 903-918
Author(s):  
Anna Krakowiak-Bal ◽  
Urszula Ziemianczyk ◽  
Andrzej Wozniak
Keyword(s):  
Rural Areas ◽  
Economic Activity ◽  
Local Development ◽  
Practical Implication ◽  
Public Investment ◽  
Empirical Work ◽  
Important Criterion ◽  
Economic Activities ◽  
Ahp Method ◽  
Content Type

Purpose The purpose of this paper is to verify the development of economic activities in rural areas in terms of their public infrastructural equipment. Design/methodology/approach As a case study, the Polish rural areas were selected. A two-stage survey was conducted in 2015. The first stage involved entrepreneurs from rural areas. The second stage of survey was data collection for rural areas regarding economic activity and infrastructural equipment. In total, 121 objects (communes) were selected. The multicriteria analytic hierarchy process (AHP) method was used for the analysis. Findings The results demonstrate that for each kind of business, communication accessibility is the most important criterion. By contrast, environmental awareness and concern for the environment is the least important element for pursuit of the economic activity in rural areas. Research limitations/implications Limitations are connected mainly with the applied AHP method. The number of the comparable elements at the same hierarchy level is limited due to practical purposes. In addition, an assumption of full comparability of elements (criteria and alternatives) in the hierarchy model can be discussed. Furthermore, data quality and availability limit the scope of the empirical work. This study is a major simplification of reality modeling, but it gives practical benefits by simplifying the decision support procedure. Practical implications The findings of this paper contribute to the advancing theory of local development, with public infrastructure being one of its basic elements (factor of production). This paper explores the importance of physical infrastructure for different economic activities, and thus offers theoretical insights in two areas. First, this paper indicates the uneven weight of each infrastructure element for the various business sectors. Second, based on the collected data, this study also contributes to the literature, by using the AHP method to explore the relationships between infrastructural equipment and economic activity in rural areas. As the practical implication for local and regional development policies, this study indicates, that the most important criterion for each kind of economic activity is communication accessibility. This kind of public investment should be undertaken primarily to support entrepreneurship, especially in rural areas. Originality/value The uniqueness of the method lies in assumption about the uneven weights of infrastructure elements and therefore their impact on the process of ranking the objects (rural areas). The weight of individual infrastructure elements will vary depending on the kind of economic activity; therefore, the way of ordering will also be different for each economic activity.

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