Advanced analyses of the membrane action of composite slabs under natural fire scenarios

2018 ◽  
Vol 9 (1) ◽  
pp. 77-90 ◽  
Author(s):  
Lorenzo Lelli ◽  
Jonas Loutan
Keyword(s):  
Gas Temperature ◽  
Reinforced Concrete Structure ◽  
Membrane Action ◽  
Content Type ◽  
Natural Fire ◽  
Small Thickness ◽  
Composite Frame ◽  
Composite Slabs ◽  
Fire Scenarios ◽  
Definition Of

Purpose This paper aims to detail the advanced natural fire simulations that were carried out for the composite steel-reinforced concrete structure of the JTI Building in Geneva, Switzerland. The results of these analyses led to a significant reduction of in the fireproofing of the steel floor framing. Design/methodology/approach Several scenarios were studied considering different thermal behaviours of the peripheral cladding. Despite the small thickness of the resisting slabs, the analyses performed with SAFIR software showed that the typical wide storey bay (12 × 15.86 m) can resist to the design’s fire temperatures without the protection of the main and secondary beams while the spandrels remain protected. For study completeness, the composite frame-membrane model was also simulated with Hasemi-localized fire routines on SAFIR. Findings The analyses have showed that the membrane behaviour of composite slabs under fire allows a significant reduction of the fire protection, even in case of small thickness of the concrete topping. The increase of the reinforcement ratio to sustain the membrane forces is widely compensated by the savings related to the fireproofing of the steel framing. Practical/implications A natural fire approach is particularly advisable in case of fully glazed buildings. In fact when the façade collapses, the entry of a large cold air quantity limits the increase of the gas temperature inside the compartment. Originality/value The analyses were carried out with recent SAFIR routines for localized fires (Hasemi fire model) and represent one of the first applications in practice. The issue of the rebar orientation in mesh is raised out. The latest SAFIR release allows the definition of a global orientation of the rebars and amends the issue.

Fire resistance of composite slabs with steel deck under natural fire

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Paulo A.G. Piloto ◽  
Carlos Balsa ◽  
Felipe Macedo Macêdo Gomes ◽  
Bergson Matias
Keyword(s):  
Fire Resistance ◽  
Numerical Models ◽  
Three Dimensional ◽  
Composite Slab ◽  
Content Type ◽  
Natural Fire ◽  
Fire Scenario ◽  
Composite Slabs ◽  
Cooling Phase ◽  
Steel Deck

PurposeMost of the numerical research and experiments on composite slabs with a steel deck have been developed to study the effect of fire during the heating phase. This manuscript aims to describe the thermal behaviour of composite slabs when submitted to different fire scenarios, considering the heating and cooling phase.Design/methodology/approachThree-dimensional numerical models, based on finite elements, are developed to analyse the temperatures inside the composite slab and, consequently, to estimate the fire resistance, considering the insulation criteria (I). The numerical methods developed are validated with experimental results available in the literature. In addition, this paper presents a parametric study of the effects on fire resistance caused by the thickness of the concrete part of the slab as well as the natural fire scenario.FindingsThe results show that, depending on the fire scenario, the fire resistance criterion can be reached during the cooling phase, especially for the thickest composite slabs. Based on the results, new coefficients are proposed for the original simplified model, proposed by the standard.Originality/valueThe developed numerical models allow us to realistically simulate the thermal effects caused by a natural fire in a composite slab and the new proposal enables us to estimate the fire resistance time of composite slabs with a steel deck, even if it occurs in the cooling phase.

Why Broadgate Phase 8 composite floor did not fail under fire

2017 ◽  
Vol 8 (3) ◽  
pp. 238-257 ◽  
Author(s):  
Simon Mwangi
Keyword(s):  
Numerical Investigation ◽  
Numerical Models ◽  
Thermomechanical Analysis ◽  
Large Strains ◽  
Structural Behaviour ◽  
Membrane Action ◽  
Content Type ◽  
Strain Pattern ◽  
Fire Scenarios ◽  
The One

Purpose This paper aims to present the findings of a numerical investigation into the performance of the steel-concrete composite floor involved in Broadgate Phase 8 fire. Design/methodology/approach The investigation is conducted by carrying out a 3-D thermomechanical analysis of a composite floor similar to the one involved in the fire using ANSYS. Four fire scenarios are investigated, with each producing a unique stress – strain pattern. The results obtained are compared with the observations made after the fire and inferences drawn. Findings The results obtained are found to be correlated with the observations made after the fire. The performance of the composite floor is found to be dominated by development of large strains, leading to large deflections. Furthermore, colder parts of the structure, through redistribution of forces, are found to have a profound impact on the ability of a composite floor to resist heating effects. From the findings, it is concluded that connections’ design, occurrence of membrane action and thermal restraints were the key reasons the floor did not fail. Originality value The study takes a more forensic approach. This is a departure from majority of published literature, where comparison is usually between experimental and numerical results. By comparing the findings from a real fire with those of a numerical investigation, the study provides an insight into the accuracy of applying numerical models for the prediction of effects of fire on structural behaviour.

scholarly journals Performance-based design of RC beams using an equivalent standard fire

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Robert Kuehnen ◽  
Maged Youssef ◽  
Salah El-Fitiany
Keyword(s):  
Performance Based Design ◽  
Rc Beams ◽  
Fire Event ◽  
Content Type ◽  
Natural Fire ◽  
Standard Fire ◽  
Fire Scenarios ◽  
The Moment ◽  
Equivalent Method ◽  
Fire Design

Purpose The design of buildings for fire events is essential to ensure occupant safety. Supplementary to simple prescriptive methods, performance-based fire design can be applied to achieve a greater level of safety and flexibility in design. To make performance-based fire design more accessible, a time-equivalent method can be used to approximate a given natural fire event using a single standard fire with a specific duration. Doing so allows for natural fire events to be linked to the wealth of existing data from the standard fire scenario. The purpose of this paper is to review and assess the application of an existing time-equivalent method in the performance-based design of reinforced concrete (RC) beams. Design/methodology/approach The assessment is established by computationally developing the moment-curvature response of RC beam sections during fire exposure. The sectional response due to natural fire and time equivalent fire are compared. Findings It is shown that the examined time equivalent method is able to predict the sectional response with suitable accuracy for performance-based design purposes. Originality/value The research is the first to provide a comprehensive evaluation of the moment-curvature diagram of RC beams using time-equivalent standard fire scenarios that model realistic fire scenarios.

Financial capabilities development: essential discourse in social work

2019 ◽  
Vol 46 (10) ◽  
pp. 1234-1246
Author(s):  
Lambert K. Engelbrecht ◽  
Abigail Ornellas
Keyword(s):  
Sustainable Development ◽  
Social Work ◽  
Financial Literacy ◽  
Community Education ◽  
Work Practice ◽  
Well Being ◽  
Social Work Practice ◽  
Content Type ◽  
Vulnerable Households ◽  
Definition Of

Purpose Within a neoliberal environment, financial vulnerability of households has become an increasing challenge and there is a requirement of financial literacy education, a necessary activity to facilitate sustainable development and well-being. However, this is seldom a mainstream discourse in social work deliberations. The paper aims to discuss these issues. Design/methodology/approach First, introducing the neoliberal impact on financial well-being and capability for vulnerable households, the authors’ postulation is substantiated on a seven-point argument. The contexts of financially vulnerable households are sketched. Second, a conceptualisation of financial literacy is offered, and third, perspectives on and approaches to financial literacy as a fundamental capability are presented. This is followed by a theoretical foundation of community education as a practice model in social work to develop financial capabilities. In the fifth place, prevailing practices of Financial Capabilities Development (FCD) programmes are offered. Subsequently, the implications of a neoliberal environment for social work practice are examined. Findings The revised global definition of social work encourages the profession to understand and address the structural causes of social problems through collective interventions. As a response, it is argued that community education towards FCD of vulnerable households within a neoliberal environment should be an essential discourse in social development. Originality/value The authors reflect on the significance of FCD, highlighting its contribution towards human security and sustainable development. Although this paper draws on Southern African contexts, the discourse finds resonance in other contexts across the world.

Collaborative design in public services: a wicked problem-reframing case

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Patrícia Moura e Sá ◽  
Catarina Frade ◽  
Fernanda Jesus ◽  
Mónica Lopes ◽  
Teresa Maneca Lima ◽  
...  
Keyword(s):  
Collaborative Design ◽  
Success Factors ◽  
Central Government ◽  
Wicked Problem ◽  
Low Density ◽  
Structured Interviews ◽  
Content Type ◽  
Critical Success ◽  
Definition Of ◽  
The Right

PurposeWicked problems require collaborative innovation approaches. Understanding the problem from the users' perspective is essential. Based on a complex and ill-defined case, the purpose of the current paper is to identify some critical success factors in defining the “right problem” to be addressed.Design/methodology/approachAn empirical research study was carried out in a low-density municipality (case study). Extensive data were collected from official databases, individual semi-structured interviews and a focus group involving citizens, local authorities, civil servants and other relevant stakeholders.FindingsAs defined by the central government, the problem to be addressed by the research team was to identify which justice services should be made available locally to a small- and low-density community. The problem was initially formulated using top-down reasoning. In-depth contact with citizens and key local players revealed that the lack of justice services was not “the issue” for that community. Mobility constraints and the shortage of economic opportunities had a considerable impact on the lack of demand for justice services. By using a bottom-up perspective, it was possible to reframe the problem to be addressed and suggest a new concept to be tested at later stages.Social implicationsThe approach followed called attention to the importance of listening to citizens and local organisations with a profound knowledge of the territory to effectively identify and circumscribe a local problem in the justice field.Originality/valueThe paper highlights the limitations of traditional rational problem-solving approaches and contributes to expanding the voice-of-the-customer principle showing how it can lead to a substantially new definition of the problem to be addressed.

Social media and consumer engagement: a review and research agenda

2016 ◽  
Vol 10 (4) ◽  
pp. 268-287 ◽  
Author(s):  
Victor Barger ◽  
James W. Peltier ◽  
Don E. Schultz
Keyword(s):  
Social Media ◽  
Recent Literature ◽  
Future Research ◽  
Consumer Engagement ◽  
Research Directions ◽  
Content Type ◽  
Future Research Directions ◽  
Antecedents And Consequences ◽  
Area Of Concern ◽  
Definition Of

Purpose In “Social media’s slippery slope: challenges, opportunities and future research directions”, Schultz and Peltier (2013) asked “whether or how social media can be used to leverage consumer engagement into highly profitable relationships for both parties”. The purpose of this article is to continue this discussion by reviewing recent literature on consumer engagement and proposing a framework for future research. Design/methodology/approach The paper reviews the marketing literature on social media, paying particular attention to consumer engagement, which was identified as a primary area of concern in Schultz and Peltier (2013). Findings A significant amount of research has been conducted on consumer engagement since 2010. Lack of consensus on the definition of the construct has led to fragmentation in the discipline, however. As a result, research related to consumer engagement is often not identified as such, making it difficult for academics and practitioners to stay abreast of developments in this area. Originality/value This critical review provides marketing academics and practitioners insights into the antecedents and consequences of consumer engagement and offers a conceptual framework for future research.

Interaction, engagement, and perceived interactivity in single-handed interaction

2016 ◽  
Vol 26 (5) ◽  
pp. 1134-1157 ◽  
Author(s):  
Donghee Shin ◽  
Myunggoon Choi ◽  
Jang Hyun Kim ◽  
Jae-gil Lee
Keyword(s):  
Behavioral Intention ◽  
Interaction Techniques ◽  
Content Type ◽  
Thumb Movement ◽  
Wide Range ◽  
Mobile Industry ◽  
Perceived Interactivity ◽  
The Subject ◽  
Definition Of ◽  
Practical Implications

Purpose The purpose of this paper is to examine the effects of interaction techniques (e.g. swiping and tapping) and the range of thumb movement on interactivity, engagement, attitude, and behavioral intention in single-handed interaction with smartphones. Design/methodology/approach A 2×2 between-participant experiment (technological features: swiping and tapping×range of thumb movement: wide and narrow) was conducted to study the effects of interaction techniques and thumb movement ranges. Findings The results showed that the range of thumb movement had significant effects on perceived interactivity, engagement, attitude, and behavioral intention, whereas no effects were observed for interaction techniques. A narrow range of thumb movement had more influence on the interactivity outcomes in comparison to a wide range of thumb movement. Practical implications While the subject of actual and perceived interactivity has been discussed, the issue has not been applied to smartphone. Based on the research results, the mobile industry may come up with a design strategy that balances feature- and perception-based interactivity. Originality/value This study adopted the perspective of the hybrid definition of interactivity, which includes both actual and perceived interactivity. Interactivity effect outcomes mediated by perceived interactivity.

Contemporary psychosurgery and a look to the future

2001 ◽  
Vol 95 (6) ◽  
pp. 944-956 ◽  
Author(s):  
Robert P. Feldman ◽  
Ronald L. Alterman ◽  
James T. Goodrich
Keyword(s):  
Modern Science ◽  
Psychiatric Disease ◽  
Content Type ◽  
Current State ◽  
Mind And Brain ◽  
Patient Selection Criteria ◽  
Definition Of ◽  
Historical Developments ◽  
The Mind ◽  
Fine Print

Object. Despite a long and controversial history, psychosurgery has persisted as a modern treatment option for some severe, medically intractable psychiatric disorders. The goal of this study was to review the current state of psychosurgery. Methods. In this review, the definition of psychosurgery, patient selection criteria, and anatomical and physiological rationales for cingulotomy, subcaudate tractotomy, anterior capsulotomy, and limbic leukotomy are discussed. The historical developments, modern procedures, and results of these four contemporary psychosurgical procedures are also reviewed. Examples of recent advances in neuroscience indicating a future role for neurosurgical intervention for psychiatric disease are also mentioned. Conclusions. A thorough understanding of contemporary psychosurgery will help neurosurgeons and other physicians face the ethical, social, and technical challenges that are sure to lie ahead as modern science continues to unlock the secrets of the mind and brain.

The operational efficiency of passenger aircraft

2006 ◽  
Vol 78 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Donald McLean
Keyword(s):  
Design Methodology ◽  
Operational Efficiency ◽  
Civil Aviation ◽  
Content Type ◽  
Transport Economics ◽  
Load Factors ◽  
Consistent Assessment ◽  
Definition Of ◽  
Passenger Aircraft ◽  
Practical Implications

PurposeTo provide for the use of airlines and other civil aviation organizations a practical definition of operational efficiency and to show how it can be determined.Design/methodology/approachA brief account of air transport economics is used to demonstrate how bom load factors and aircraft utilization need to be considered in assessing operational efficiency. Then other efficiencies are treated briefly before an example is given of how the better of two fictitious aircraft can be chosen for a particular route. A second example involving the calculation of the operational efficiency achieved by an imaginary airline is also given to show that the typical value is lower than might be expected, particularly in view of the relatively high load factors involved.FindingsProvides performance values and economic figures which are typical of current airline operations.Practical implicationsUse of the proposed definition will allow the consistent assessment of the economic performance of airlines.Originality/valueAt present there is no definition of operational efficiency in general use although it is greatly needed by airlines. The definition proposed in this paper is practical and easy to use.

Digital competences of the workforce – a research topic?

2017 ◽  
Vol 23 (3) ◽  
pp. 721-734 ◽  
Author(s):  
Matthias Murawski ◽  
Markus Bick
Keyword(s):  
Research Topic ◽  
Future Research ◽  
Digital Competence ◽  
Content Type ◽  
Research Activities ◽  
Starting Point ◽  
Pros And Cons ◽  
Definition Of ◽  
The Individual ◽  
Practical Implications

Purpose Considering working in the digital age, questions on the consequences for the individual workers are, so far, often neglected. The purpose of this paper is to deal with the question of whether the digital competences of the workforce is a research topic. The authors argue for the thesis that it is indeed a research topic. Design/methodology/approach In addition to a literature analysis of the top IS, HR, and learning publications, non-scientific sources, as well as the opinions of the authors, are included. The authors’ thesis is challenged through a debate of corresponding pros and cons. Findings The definition of digital competences lacks scientific depth. Focussing on the workforce is valid, as a “lifelong” perspective is not mandatory for research. Digital competence research is a multidisciplinary task to which the IS field can make a valuable contribution. Research limitations/implications Although relevant references are included, some aspects are mainly driven by the opinions of the authors. The theoretical implications encompass a call for a scientific definition of digital competences. Furthermore, scholars should focus on the competences of the workforce, including occupations, roles, or industries. The authors conclude by providing a first proposal of a research agenda. Practical implications The practical implications include the alignment of multiple stakeholders for the design of “digital” curricula and the integration by HR departments of the construct of digital competences, e.g. for compensation matters and job requirements. Originality/value This paper is one of very few contributions in the area of the digital competences of the workforce, and it presents a starting point for future research activities.

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