Temperature analysis of extended end plate joints to square CFST columns in fire

2016 ◽  
Vol 7 (4) ◽  
pp. 306-315
Author(s):  
Jing-feng Wang ◽  
Hai-Tao Wang ◽  
Wei-Wei Shi ◽  
Hong-Yu Sheng
Keyword(s):  
Temperature Distribution ◽  
Test Results ◽  
Content Type ◽  
Composite Frames ◽  
Composite Joint ◽  
Fire Condition ◽  
Temperature Filed ◽  
Cfst Columns ◽  
Rigid Joints ◽  
In Fire

Purpose This paper aims to obtain fire resistance of semi-rigid joints for concrete-filled steel tubular (CFST) composite frames and temperature filed distribution of composite joints in fire. Design/methodology/approach The temperature filed model of semi-rigid joints to CFST columns with slabs was made by using ABAQUS finite element (FE) software, in considering temperature heating-up stage of fire modelling. The effects of composite slab, fire type and construction location were discussed, and the model was verified by the test results. The temperature distribution of composite joint under three-side or four-side fire condition was studied by the sequentially coupled thermal analysis method. The temperature versus time curves and temperature distribution of various construction and location were analyzed. Findings The paper provides FE analysis and numerical simulation on temperature field of semi-rigid joints for CFST composite frames in fire. The effects of composite slab, fire type and construction location were discussed, and the model was verified by the test results. It suggests that the temperature distribution of composite joint in three- or four-side fire condition showed a different development trend. Research limitations/implications Because of the chosen FE analysis approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the proposed propositions further. Practical implications The research results will become the scientific foundation of mechanical behavior and design method of semi-rigid CFST composite frames in fire. Originality/value This paper fulfils an identified need to study the temperature field distribution of the semi-rigid joints to CFST columns and investigate the mechanical behavior of the semi-rigid CFST joints in fire.

Structural fire performance of wood-steel-wood bolted connections with and without perpendicular-to-wood grain reinforcement

2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Adam Roman Petrycki ◽  
Osama (Sam) Salem
Keyword(s):  
Time To Failure ◽  
Bolted Connections ◽  
Content Type ◽  
Structural Fire ◽  
Fire Condition ◽  
Glued Laminated Timber ◽  
End Distance ◽  
Wood Grain ◽  
Mass Timber ◽  
In Fire

Purpose In fire condition, the time to failure of a timber connection is mainly reliant on the wood charring rate, the strength of the residual wood section, and the limiting temperature of the steel connectors involved in the connection. The purpose of this study is to experimentally investigate the effects of loaded bolt end distance, number of bolt rows, and the existence of perpendicular-to-wood grain reinforcement on the structural fire behavior of semi-rigid glued-laminated timber (glulam) beam-to-column connections that used steel bolts and concealed steel plate connectors. Design/methodology/approach In total, 16 beam-to-column connections, which were fabricated in wood-steel-wood bolted connection configurations, in eight large-scale sub-frame test assemblies were exposed to elevated temperatures that followed CAN/ULC-S101 standard time-temperature curve, while being subjected to monotonic loading. The beam-to-column connections of four of the eight test assemblies were reinforced perpendicular to the wood grain using self-tapping screws (STS). Fire tests were terminated upon achieving the failure criterion, which predominantly was dependent on the connection’s maximum allowed rotation. Findings Experimental results revealed that increasing the number of bolt rows from two to three, each of two bolts, increased the connection’s time to failure by a greater time increment than that achieved by increasing the bolt end distance from four- to five-times the bolt diameter. Also, the use of STS reinforcement increased the connection’s time to failure by greater time increments than those achieved by increasing the number of bolt rows or the bolt end distance. Originality/value The invaluable experimental data obtained from this study can be effectively used to provide insight and better understanding on how mass-timber glulam bolted connections can behave in fire condition. This can also help in further improving the existing design guidelines for mass-timber structures. Currently, beam-to-column wood connections are designed mainly as axially loaded connections with no guidelines available for determining the fire resistance of timber connections exerting any degree of moment-resisting capability.

scholarly journals Experimental and numerical investigation of post-tensioned concrete flat slabs in fire

2016 ◽  
Vol 7 (1) ◽  
pp. 2-18 ◽  
Author(s):  
Ya Wei ◽  
Francis T.K. Au ◽  
Jing Li ◽  
Neil C.M. Tsang
Keyword(s):  
High Strength ◽  
Test Results ◽  
Self Compacting Concrete ◽  
Content Type ◽  
Moisture Contents ◽  
Flat Slabs ◽  
Unbonded Tendons ◽  
In Fire ◽  
Fire Conditions ◽  
Post Tensioned

Purpose This paper aims to understand the structural fire performance of two-way post-tensioned flat slabs, particularly their deformations and load-carrying mechanisms in fire, and to explore the behaviour of post-tensioned high-strength self-compacting concrete flat slabs with unbonded tendons in fire. Design/methodology/approach Four tests of post-tensioned high-strength self-compacting concrete flat slabs were conducted under fire conditions. Numerical modelling using the commercial package ABAQUS was conducted to help interpret the test results. Findings Two of the specimens with lower moisture contents demonstrated excellent fire resistance performance, while the others with slightly higher moisture contents experienced severe concrete spalling. Originality/value The test results were discussed in respect of thermal profiles, deflections, crack patterns and concrete spalling. The performance of post-tensioned high-strength self-compacting concrete flat slabs with unbonded tendons under fire conditions was better understood.

How bracing and heating regimes influence the fire performance of composite frames

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Oliver Bahr
Keyword(s):  
Numerical Model ◽  
Shear Failure ◽  
Braced Frames ◽  
Load Bearing ◽  
Content Type ◽  
Standard Fire ◽  
Composite Frames ◽  
Local Stresses ◽  
In Fire ◽  
Fire Design

Purpose Unbraced one-bay composite frames are an interesting load-bearing structure for buildings with up to three storeys. However, their fire design is demanding given the lack of simplified design methods. This paper aims to deepen the understanding of the load-bearing behaviour of both unbraced and braced frames when exposed to fire. Design/methodology/approach In a previous paper, a numerical model for the fire design of these frames was established and validated with good agreement against fire tests. In the current paper, this model was used to compare the typical differences between braced, semi-braced and unbraced composite frames under fire conditions. Further studies addressed the effect of different heating regimes, i.e. partial fire exposure of the columns in the frames and varying location of the ISO standard fire. Findings Numerical investigations showed that it is necessary to take local failure and deformation limits of the fire-exposed frames into account. On this basis, unbraced composite frames can compete with braced frames as they have to endure less thermal restraints than braced frames. Originality/value In contrast to other investigations on frames, the numerical model is able to take into account the shear failure, which is especially important within the frame corners. Using this model, it is shown that limited sway is reasonable to reduce thermal restraints and hence local stresses. In this regard, the concept of semi-rigid composite joints with a distinct amount of reinforcement has proven to be very rational in fire design.

On the fire performance of unbraced composite frames

2018 ◽  
Vol 9 (4) ◽  
pp. 300-318 ◽  
Author(s):  
Oliver Bahr
Keyword(s):  
Numerical Model ◽  
Large Scale ◽  
Composite Joints ◽  
Fire Tests ◽  
Fire Performance ◽  
Structural Behaviour ◽  
Content Type ◽  
Composite Frames ◽  
Composite Joint ◽  
Fire Design

Purpose The purpose of this study is to gain a deeper understanding of the structural behaviour of fire-exposed unbraced composite frames. Designers to date paid little attention to unbraced one-bay composite frames as structural system. There are two main reasons for this. First, codes lack simplified methods for the fire design of these frames due to their sway and the linked P-Δ effects when subjected to fire, which complicates the design. Second, it is demanding to construct external composite joints for the regarded one-bay frames. Thus, external joints in composite constructions are mostly constructed as steel joints. Nevertheless, these frames offer advantages. These include increased usable space and flexibility in the building’s use, large spans, fast construction times and inherent fire resistance. Design/methodology/approach To profit from these benefits, two different external semi-rigid composite joint were developed for the considered one-bay composite frames. The first solution based on concrete-filled steel tube columns and the second on concrete-filled double skin tube columns. Furthermore, a numerical model was established to study the fire performance of unbraced composite frames. The model was validated against four fire tests on isolated composite joints and two large-scale fire tests on unbraced composite frames. Findings Overall, the predictions of the numerical model were in good agreement with the test results. Thus, the numerical model is appropriate for further investigations on the fire performance of unbraced composite frames. Originality/value The sequence of construction results in significant stresses in the steel section, which creates difficulties in numerical modelling and may account for the relatively few studies carried out at room temperature. For the fire design, there was, to the best knowledge of the author, to date no numerical model available that was capable of considering the sequence of construction.

Preliminary Study on Post-Fire Behavior of Composite Frame with CFST Columns and Composite Beam

2010 ◽  
Vol 163-167 ◽  
pp. 713-716
Author(s):  
Peng Peng Zhang ◽  
Wen Da Wang ◽  
Jing Xuan Wang
Keyword(s):  
Concrete Slab ◽  
Fire Behavior ◽  
Material Model ◽  
Element Model ◽  
Reinforced Concrete Slab ◽  
Composite Frames ◽  
Composite Frame ◽  
Composite Joint ◽  
Element Type ◽  
Cfst Columns

A 3-D finite element model (FEM) using ABAQUS was introduced in this paper to simulate the post-fire behavior of composite frames with concrete-filled steel tubular (CFST) columns and steel beam with reinforced concrete slab. Accurate thermal and material model, element type, and solution method were assumed in the model considering the temperature effect during the fire. Some composite joint specimen post-fire tests were modeled using the FEM. The results obtained from the FEM were verified against those experimental results. The mechanism of the composite frame was investigated based on the FEM.

New product and emerging business growth in Kwara State

2016 ◽  
Vol 12 (3) ◽  
pp. 207-227 ◽  
Author(s):  
Seun Oladele ◽  
Femi Oladele
Keyword(s):  
Market Share ◽  
Manufacturing Industry ◽  
Service Industry ◽  
New Product ◽  
Sales Volume ◽  
Test Results ◽  
Business Growth ◽  
Content Type ◽  
Product Service ◽  
Service Portfolio

Purpose – The purpose of this paper is to examine the effect of new product on growth of emerging businesses (EBs) through sales volume and market share. Design/methodology/approach – The study surveyed 137 EBs in Kwara State. Two hypotheses were formulated and tested using correlation and regression analyses. Findings – Results show that service industry is dominant among EBs while the manufacturing industry trails. Many EBs are aware of the complexities of new product, its development and contribution to increasing sales volume, market share and ensuring competitive advantage with apparent infrastructural deficiencies. Test results show that there is a significant positive relationship and effect on sales volume and market share. Originality/value – Encouraging EBs to step up and focus on improving product/service portfolio to transform their fortune is explored giving focus to the benefits of increasing sales volume and market share.

Analysis on hysteretic behavior of composite frames with concrete-encased CFST columns

2017 ◽  
Vol 135 ◽  
pp. 176-186 ◽  
Author(s):  
Kun Wang ◽  
Xiao-Feng Lu ◽  
Shen-Feng Yuan ◽  
Da-Fu Cao ◽  
Zai-Xian Chen
Keyword(s):  
Hysteretic Behavior ◽  
Composite Frames ◽  
Cfst Columns

Review of Fire Performance Experiment of Concrete-Filled Steel Tubular Columns

2014 ◽  
Vol 638-640 ◽  
pp. 1397-1401
Author(s):  
Kai Xiang ◽  
Guo Hui Wang ◽  
Yan Chong Pan
Keyword(s):  
Load Ratio ◽  
Experimental Results ◽  
Research Progress ◽  
Future Research ◽  
Fire Performance ◽  
Cross Sectional ◽  
Tubular Columns ◽  
Cross Sectional Dimension ◽  
Cfst Columns ◽  
In Fire

This paper presents a review of research progress in fire performance of concrete-filled steel tubular (CFST) columns. Experimental results of CFST columns in fire are reviewed with influence parameters, such as heights, cross-sectional dimension, section types, concrete types, concrete strengths, load ratio, load eccentricity, fire exposed sides and so on. Some conclusions of CFST columns under fire conditions are summarized. Deficiencies in the fire performance experiments of CFST columns are identified, which provide the focus for future research in the field.

scholarly journals The drivers of economic growth in China and India: globalization or financial development?

2017 ◽  
Vol 16 (1) ◽  
pp. 54-84 ◽  
Author(s):  
Magda Kandil ◽  
Muhammad Shahbaz ◽  
Mantu Kumar Mahalik ◽  
Duc Khuong Nguyen
Keyword(s):  
Economic Growth ◽  
Financial Development ◽  
Emerging Market ◽  
Annual Data ◽  
Test Results ◽  
Causality Test ◽  
Content Type ◽  
China And India ◽  
Integration Test ◽  
The Impact

Purpose Using annual data from 1970 to 2013 for China and India, this paper aims to examine the impact of globalization and financial development on economic growth by endogenizing capital and inflation and drawing comparisons between the two fastest growing emerging market economies. Design/methodology/approach In the long run, co-integration test results indicate that financial development increases economic growth in China and India. Findings The results also reveal that globalization accelerates economic growth in India but, surprisingly, impairs economic growth in China, as it increases competition for exports. The results furthermore disclose that acceleration in capitalization and inflation, as a proxy for aggregate demand, are positively linked to economic growth in China and India. Originality/value Causality test results indicate that both financial development and economic growth are interdependent. In contrast, causality runs from higher economic growth to increased globalization in India, while the results do not support long-term causality between globalization and economic growth in China.

Study of mechanical properties of indium-based solder alloys for cryogenic applications

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Madhuri Chandrashekhar Deshpande ◽  
Rajesh Chaudhari ◽  
Ramesh Narayanan ◽  
Harishwar Kale
Keyword(s):  
Mechanical Properties ◽  
Solder Alloy ◽  
Charpy Impact ◽  
Charpy Impact Test ◽  
Test Results ◽  
Solder Alloys ◽  
Content Type ◽  
Electron Microscope Analysis ◽  
American Society ◽  
Work Done

Purpose This study aims to develop indium-based solders for cryogenic applications. Design/methodology/approach This paper aims to investigate mechanical properties of indium-based solder formulations at room temperature (RT, 27 °C) as well as at cryogenic temperature (CT, −196 °C) and subsequently to find out their suitability for cryogenic applications. After developing these alloys, mechanical properties such as tensile and impact strength were measured as per American Society for Testing and Materials standards at RT and at CT. Charpy impact test results were used to find out ductile to brittle transition temperature (DBTT). These properties were also evaluated after thermal cycling (TC) to find out effect of thermal stress. Scanning electron microscope analysis was performed to understand fracture mechanism. Results indicate that amongst the solder alloys that have been studied in this work, In-34Bi solder alloy has the best all-round mechanical properties at RT, CT and after TC. Findings It can be concluded from the results of this work that In-34Bi solder alloy has best all-round mechanical properties at RT, CT and after TC and therefore is the most appropriate solder alloy amongst the alloys that have been studied in this work for cryogenic applications Originality/value DBTT of indium-based solder alloys has not been found out in the work done so far in this category. DBTT is necessary to decide safe working temperature range of the alloy. Also the effect of TC, which is one of the major reasons of failure, was not studied so far. These parameters are studied in this work.

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