Adaption of active boundary conditions in structural fire testing

2019 ◽  
Vol 10 (4) ◽  
pp. 504-528
Author(s):  
Ramla Karim Qureshi ◽  
Negar Elhami-Khorasani ◽  
Thomas Gernay
Keyword(s):  
Boundary Conditions ◽  
Structural Steel ◽  
Test Specimen ◽  
Fire Test ◽  
Structural Elements ◽  
Fire Testing ◽  
Content Type ◽  
Steel Columns ◽  
History Of ◽  
Force Displacement

Purpose This paper aims to investigate the need for active boundary conditions during fire testing of structural elements, review existing studies on hybrid fire testing (HFT), a technique that would ensure updating of boundary conditions during a fire test, and propose a compensation scheme to mitigate instabilities in the hybrid testing procedure. Design/methodology/approach The paper focuses on structural steel columns and starts with a detailed literature review of steel column fire tests in the past few decades with varying axial and rotational end restraints. The review is followed with new results from comparative numerical analyses of structural steel columns with various end constraints. HFT is then discussed as a potential solution to be adapted for fire testing of structural elements. Challenges in contemporary HFT procedures are discussed, and application of stiffness updating approaches is demonstrated. Findings The reviewed studies indicate that axial and rotational restraints at the boundaries considerably influence the fire response of steel columns. Equivalent static spring technique for simulating effect of surrounding frame on an isolated column behavior does not depict accurate buckling and post-buckling response. Additionally, numerical models that simulate fire performance of a column situated in a full-frame do follow the trends observed in actual test results up until failure occurs, but these simulations do not necessarily capture post-failure performance accurately. HFT can be used to capture proper boundary conditions during testing of isolated elements, as well as correct failure modes. However, existing studies showed cases with instabilities during HFT. This paper demonstrates that a different stiffness updates calculated from the force-displacement response history of test specimen at elevated temperature can be used to resolve stability issues. Originality/value The paper has two contributions: it suggests that the provision of active boundary conditions is needed in structural fire testing, as equivalent static spring does not necessarily capture the effect of surrounding frame on an isolated element during a fire test, and it shows that force-displacement response history of test specimen during HFT can be used in the form of a stiffness update to ensure test stability.

Mechanical integrity of gas turbine enclosure doors under fire test conditions for A0 fire rating

2019 ◽  
Vol 10 (1) ◽  
pp. 76-89
Author(s):  
Prabhakar Sathujoda ◽  
Paul Arnell ◽  
Andrew Deans
Keyword(s):  
Finite Element ◽  
Gas Turbine ◽  
Test Specimen ◽  
Fire Test ◽  
Test Facility ◽  
Fire Testing ◽  
Content Type ◽  
Mechanical Integrity ◽  
Standard Fire ◽  
The Doors

PurposeAs fire doors are passive fire protection parts, the doors have to be certified through standard fire tests. It is usual practice to perform the standard fire testing on the components which require the fire certification. However, some gas turbine enclosure doors are too large to test at the test facility and hence the fire resistance test is practically not possible. The purpose of this paper is to develop a reliable finite element model, validate the model using the specimen door test results and extend the method to actual gas turbine enclosure doors to support the fire certification.Design/methodology/approachFirst, the standard fire testing on enclosure door test specimen was carried out. Second, the finite element analysis model was built and tuned to match the standard fire test deflections, and finally, the same modelling technique was extended to model the actual gas turbine enclosure door to verify the results for fire certification process.FindingsGap analysis, a method of post processing is suggested for result analysis. It was found suitable to verify the gap openings which are required for A0 rated fire certification according to fire test procedure code and also to check the mechanical integrity of the enclosure door frame assembly.Originality/valueThe method presented in this work could be used as support information along with the test specimen results for A0 class fire rating certification of the doors according to International Maritime Organization Resolution MSC.307 (88) Annexure 1: Part 3.

Concrete Fire Testing - A Review of the Thermal Boundary Conditions

2016 ◽  
Vol 711 ◽  
pp. 496-503
Author(s):  
Cristian Maluk
Keyword(s):  
Boundary Conditions ◽  
Experimental Studies ◽  
Time History ◽  
Concrete Specimen ◽  
Radiant Heat ◽  
Heat Fluxes ◽  
Fire Testing ◽  
Conservation Of Energy ◽  
Thermal Boundary Conditions ◽  
History Of

Experimental studies of concrete in fire or at elevated temperature have traditionally given relatively little scientific attention to quantifying the severity, and to some extent reproducibility, of the thermal boundary conditions imposed on specimens during testing. This paper examines the heat transfer fundamentals of fire testing when controlling the time-history of temperature inside a furnace (or oven), versus controlling the time-history of incident radiant heat flux at a specimen’s exposed surface. The thermal boundary conditions of a concrete specimen during fire testing are fundamentally based on conservation of energy, and thus typically formulated in terms of heat fluxes. While from the standpoint of concrete fire behaviour the aim is typically only to gauge the distribution of temperatures inside concrete; this is rarely explicitly acknowledged or quantified during concrete fire testing. This shows that continued unexamined use of varied heating techniques presents a serious threat to harmonization of the thermal boundary conditions imposed during concrete testing. The current work proposes adopting test control by in-depth temperature distributions or net heat fluxes for a rigorous comparison of the thermal boundary conditions imposed on test specimens when using different heating techniques.

Numerical analysis of steel columns subjected to fire

2019 ◽  
Vol 15 (2) ◽  
pp. 387-397
Author(s):  
Yagho S. Simões ◽  
Fabio M. Rocha ◽  
Jorge Munaiar Neto
Keyword(s):  
High Temperatures ◽  
Structural Response ◽  
Thermal Action ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Content Type ◽  
Steel Columns ◽  
Constituent Material ◽  
Engineering Problems ◽  
Method Formulation

Purpose Isolated steel columns, when exposed to high temperatures, lose strength in a few minutes due to the high thermal conductivity of its constituent material. When these structural elements are embedded in walls, the response to exceptional action is altered so that the compartmentation offers an increase in the fire resistance of the columns. Therefore, the purpose of this paper is to analyze the behavior of steel columns inserted in walls subject to thermal action in a numerical context. Design/methodology/approach For this purpose, the computational code ABAQUS version 6.14, which applies the finite element method formulation to solve engineering problems, was used. Findings The thermo-mechanical modeling, considering the wall only as a compartmentation element, generated few consistent results, leading to the conclusion that the walls influence the structural response of columns in a fire situation. Originality/value There is a lack of both numerical and experimental research works. In numerical modeling, the research works found in the literature had difficulties in developing a numerical model that satisfactorily represented steel columns inserted in walls, not being able to adequately understand their behavior at high temperatures. All of them did not consider the influence of masonry on the thermo-structural behavior of the columns. In this paper, this influence was evaluated and discussed.

A tribute to Gwen Leighty

2006 ◽  
Vol 19 (2) ◽  
pp. 84-86
Author(s):  
Jennifer Paustenbaugh
Keyword(s):  
Web Sites ◽  
Academic Libraries ◽  
Design Methodology ◽  
Fund Raising ◽  
Personal Knowledge ◽  
Valuable Contribution ◽  
Content Type ◽  
History Of ◽  
Development Network ◽  
Fund Raiser

PurposeThe purpose of the paper is to provide a tribute to the life and work of library fund‐raiser Gwen Leighty.Design/methodology/approachThe paper uses personal knowledge and references to Academic Libraries Advancement and Development Network (ALADN) and LIBDEV web sites.FindingsThe paper finds that fundraising is connecting with people and the journey that each development officer must make while raising funds for their library.Originality/valueThe paper presents a brief history of ALADN and the valuable contribution one person made to the cause of library fund‐raising.

scholarly journals A numerical study of the impact perforation of sandwich panels with graded hollow sphere cores

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110094
Author(s):  
Ibrahim Elnasri ◽  
Han Zhao
Keyword(s):  
Boundary Conditions ◽  
Hollow Sphere ◽  
Sandwich Panel ◽  
Numerical Study ◽  
Sandwich Panels ◽  
Hopkinson Bar ◽  
Core Density ◽  
The Core ◽  
The Impact ◽  
Force Displacement

In this study, we numerically investigate the impact perforation of sandwich panels made of 0.8 mm 2024-T3 aluminum alloy skin sheets and graded polymeric hollow sphere cores with four different gradient profiles. A suitable numerical model was conducted using the LS-DYNA code, calibrated with an inverse perforation test, instrumented with a Hopkinson bar, and validated using experimental data from the literature. Moreover, the effects of quasi-static loading, landing rates, and boundary conditions on the perforation resistance of the studied graded core sandwich panels were discussed. The simulation results showed that the piercing force–displacement response of the graded core sandwich panels is affected by the core density gradient profiles. Besides, the energy absorption capability can be effectively enhanced by modifying the arrangement of the core layers with unclumping boundary conditions in the graded core sandwich panel, which is rather too hard to achieve with clumping boundary conditions.

The 4Cs of mass customization in service industries: a customer lens

2020 ◽  
Vol 34 (4) ◽  
pp. 499-511 ◽  
Author(s):  
Jessica L. Pallant ◽  
Sean Sands ◽  
Ingo Oswald Karpen
Keyword(s):  
Boundary Conditions ◽  
Mass Customization ◽  
Design Methodology ◽  
Service Industries ◽  
Future Research ◽  
Practical Application ◽  
Theoretical Understanding ◽  
Content Type ◽  
Priority Areas ◽  
Research Priority

Purpose Increasingly, customers are demanding products that fit their individual needs. Many firms respond by cultivating product individualization via mass customization, often integrating this capability via interactive platforms that connect them with customers. Despite such customization, research to date has lacked cohesion, often taking the organizational, rather than customer, view. The purpose of this paper is to provide inconclusive theorizing in regard to customization from the consumers’ perspective. Design/methodology/approach The review and synthesis of the literature revealed that co-configuration is an underexplored domain of mass customization. Consequently, an initial conceptualization of co-configuration is developed and compared with current customization strategies. Specifically, the definition and boundary conditions of co-configuration are compared with three domains of mass customization, namely, co-production, co-construction and co-design. This led to the development of research priority areas to establish an agenda for future research on mass customization and its role in customer’ firm relationships. Findings This paper provides the delineation of four distinct consumer customization strategies, conceptualized in a matrix, and proposes separate customer journey visualizations. In advancing the theoretical understanding by means of a unifying typology, this paper identifies three existing Cs of mass customization (co-production, co-construction and co-design) and focuses specifically on a fourth (co-configuration), identified as an understudied mass customization strategy. Originality/value This paper extends the previous conceptualizations of mass customization comprising co-production, co-design and co-construction. The proposed typology establishes a foundation for four research priority areas that can improve both academic rigor and practical application.

The sediment of the Hostivar Reservoir (Prague, Czech Republic) as a memory of 45 years of pollution

2017 ◽  
Vol 28 (2) ◽  
pp. 204-213
Author(s):  
Lucie Soucková ◽  
Dana Kominkova
Keyword(s):  
Czech Republic ◽  
Design Methodology ◽  
Polyaromatic Hydrocarbons ◽  
Reservoir Sediment ◽  
Terrestrial Environment ◽  
Content Type ◽  
Sediment Extraction ◽  
History Of ◽  
Us Epa ◽  
Practical Implications

Purpose The purpose of this paper is to evaluate the historical pollution of the Hostivar Reservoir (largest reservoir in Prague) sediment by metals, polyaromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB) and identify the trends in pollution of aquatic environment. Design/methodology/approach Core samples, 140 cm long, recording the 45-year history of the reservoir, were separated to 5 cm width subsamples (approximately 1.5 years of sedimentation) and analyzed for metals (Cd, Pb, Cu, Zn, Cr, Ni, Al), PAH and PCB. Following methods were used: US EPA 3051 for metals, US EPA 505 and US EPA 8082 A for PCB, and ISO 18287:2006 for PAH. Findings Most of the contaminants had the highest concentration at the beginning of the existence of the reservoir, suggesting that the contamination results from construction activities. Significant decrease of Pb occurred in the second half of the 1990s. It was caused by termination of the addition of lead as a detonation suppressant to the gasoline. Most concentrations of PAHs, PCBs and metals, except copper do not present eco-toxicological risk. Practical implications The results show the volume of priority pollutants removed from the reservoir by sediment extraction, and point risk to the terrestrial environment due to application of the sediment in the construction of a noise protecting wall. Originality/value The paper presents unique data about historical contamination of the largest reservoir in Prague, the capital of Czech Republic. It shows how the watershed and the construction phase of the dam cause a pollution of the reservoir sediment and possible environmental risk for aquatic biota.

A brief history of small business in Australia, 1970-2010

2014 ◽  
Vol 3 (2) ◽  
pp. 222-236 ◽  
Author(s):  
Michael T. Schaper
Keyword(s):  
Small Business ◽  
Small Firms ◽  
Formal Education ◽  
Extensive Literature ◽  
Business Sector ◽  
Role Of Government ◽  
Content Type ◽  
Support Tools ◽  
History Of ◽  
Training And Research

Purpose – The purpose of this paper is to provide an overview of the development of the SME sector in Australia, concentrating on a number of key areas: small business definitions and numbers; the role of government; the emergence of key industry groups; and the evolution of education, training and research services. Design/methodology/approach – The study is a result of extensive literature reviews, desk research and the recollections of various participants in the field. Findings – There have been major changes to the Australian small business sector over the last 40 years. In 1983-1984 there were an estimated 550,000 small firms, and by 2010 this had grown to almost two million. Government involvement in, and support for, SMEs was virtually non-existent before 1970. Following the delivery of the Wiltshire report (1971), however, both state and federal governments responded by developing specialist advisory services, funding programmes and other support tools. Virtually non-existent before the 1970s, several peak industry associations were formed between 1977 and the 1990s. At the same time, formal education and teaching in the area expanded in the 1970s and 1980s and is now widespread. Practical implications – Development of the small business sector in Australia has often paralleled similar trends in other OECD nations. State and territory governments have often (but not always) been the principal drivers of policy change. Originality/value – There has been no little, if any, prior documentation of the evolution of the small business sector in Australia in the last 40 years.

Haunted by the past: transformations and daily challenges of China's prosthetics

2020 ◽  
Vol 10 (1) ◽  
pp. 115-124
Author(s):  
Chunchun Wang
Keyword(s):  
Design Methodology ◽  
Cross Cultural ◽  
Future Research ◽  
Institutional Pressures ◽  
Rehabilitation Center ◽  
Content Type ◽  
The Past ◽  
Daily Experiences ◽  
History Of ◽  
Depth Interviews

PurposeThe purpose of this paper is to examine the transformations of prosthetic practices in China, as well as the daily experiences and dilemmas arising from the everchanging practices since 1949. On the basis of materials, this paper explores an everyday perspective to review the history of technology.Design/methodology/approachEthnography was collected with the application of participant observations, informal interviews and in-depth interviews during a 13-months study at a rehabilitation center in Chengdu, China. The literature on prosthetic manufacturing was also reviewed for this paper.FindingsChina's prosthetic technology seems to evolve from traditional to modern. However, this progressive narrative – innovation-based timeline (Edgerton, 2006, xi) – has been challenged by daily practices. Due to institutional pressures, prosthetists are in a dilemma of selectively using their knowledge to create one kind of device for all prosthesis users with a certain kind of disability, thereby regulating the physical and social experiences of prosthesis users. Besides, prosthesis users are accustomed to prostheses made with old techniques, and must correct themselves from old experiences to the daily practices recognized by the selected techniques.Originality/valueThis paper provides a cross-cultural case to reexamine Edgerton's criticism of the progressive and orderly innovation-centric technological narrative. More importantly, it reviews the history and practices of China's prosthetics from daily experiences rather than Edgerton's concentration on technology; therefore, it provides an everyday perspective for future research on technological transformations.

Political radicalization and fragmentation of the democratic blocs and the legislative council elections in the Hong Kong Special Administrative Region

2017 ◽  
Vol 6 (4) ◽  
pp. 372-384
Author(s):  
Chung Fun Steven Hung
Keyword(s):  
Hong Kong ◽  
Political Parties ◽  
Special Administrative Region ◽  
Content Type ◽  
Legislative Council ◽  
Administrative Region ◽  
Two Systems ◽  
History Of ◽  
One Country Two Systems ◽  
Historical Comparative

Purpose After direct elections were instituted in Hong Kong and the sovereignty was transferred from Britain to China, politicization inevitably followed democratization. The purpose of this paper is to evaluate the pro-democratic political parties’ politics in Hong Kong in recent history. Design/methodology/approach The research was conducted through a historical comparative analysis, within the context of Hong Kong after the sovereignty handover and the interim period of crucial democratization. Findings With the implementation of “One country, Two systems,” political democratization was hindered in Hong Kong’s transformation. The democratic forces have no alternative but to seek more radicalized politics, which has caused a decisive and ineluctable fragmentation of the local political parties. Originality/value This paper explores and evaluates the political history of the Hong Kong Special Administrative Region under “One country, Two systems” and the ways in which the limited democratization hinders the progress of Hong Kong’s transformation.

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