scholarly journals Numerical and Experimental Studies of Cold-formed Steel Floor Systems Made of Hollow Flange Section Joists in Fire

2015 ◽  
Author(s):  
Varathananthan Jatheeshan
Keyword(s):  
Experimental Studies ◽  
Floor Systems ◽  
Cold Formed Steel ◽  
In Fire

scholarly journals Theoretical and Experimental Studies of Timber Composite Beams Reinforced by Cold Formed Steel Sheets

2015 ◽  
Vol 5 (3) ◽  
pp. 50-63 ◽  
Author(s):  
Vilma França Monteiro ◽  
Edgar Bacarji ◽  
Orlando Ferreira Gomes ◽  
Francisco Antonio Rocco Lahr ◽  
André Luis Christoforo
Keyword(s):  
Experimental Studies ◽  
Composite Beams ◽  
Steel Sheets ◽  
Cold Formed Steel

Experimental analysis of cold-formed steel columns with intermediate and edge stiffeners in fire

2020 ◽  
Vol 146 ◽  
pp. 106481 ◽  
Author(s):  
Luís Laím ◽  
Hélder D. Craveiro ◽  
Rui Simões ◽  
André Escudeiro ◽  
Alexandre Mota
Keyword(s):  
Experimental Analysis ◽  
Steel Columns ◽  
Cold Formed Steel ◽  
In Fire

Using of Plastic Hinges in the Calculation of Buildings against Progressive Collapse under Fire Exposure

2018 ◽  
Vol 878 ◽  
pp. 115-120
Author(s):  
Levon Avetisyan
Keyword(s):  
Reinforced Concrete ◽  
Progressive Collapse ◽  
Experimental Studies ◽  
Fire Exposure ◽  
Reinforced Concrete Frame ◽  
Dynamic Calculation ◽  
Plastic Hinges ◽  
Concrete Frame ◽  
In Fire ◽  
Concrete Elements

This article presents a study of the strength of a 25-storey reinforced concrete frame against progressive collapse in fire conditions. Taking into account the angles of disclosure of plastic hinges as norming for the strength of reinforced concrete elements, a computer technology program has been developed and included in PR Wolfram Mathematica 10 for the dynamic calculation of compressed reinforced concrete elements under fire exposure on the basis of the conducted experimental studies. Dynamic calculation of the strength of eccentrically compressed reinforced concrete columns was carried out, with operation in normal conditions and under high temperatures. The diagram «moment-curvature» and the graph of the change of the static and dynamic strength of the column depending on the temperature were developed. Nonlinear dynamic analysis of a 25-storey reinforced concrete frame was conducted, taking into account the changes of the dynamic characteristics of reinforced concrete elements in fire and, the estimation of resistance of the frame was given.

Human-induced vibration of cold-formed steel floor systems: Parametric studies

2020 ◽  
Vol 23 (10) ◽  
pp. 2030-2043
Author(s):  
Sigong Zhang ◽  
Lei Xu
Keyword(s):  
Small Mass ◽  
Design Guidelines ◽  
Dynamic Responses ◽  
Human Walking ◽  
Mass Ratios ◽  
Floor Systems ◽  
Floor Vibrations ◽  
Parametric Studies ◽  
Cold Formed Steel ◽  
Loading Methods

Designing a lightweight floor to prevent annoying vibrations induced by human activities is still a challenge because numerous factors need to be considered. In consequence, there is still a lack of reliable models and adequate design guidelines pertinent to the vibration serviceability of cold-formed steel floor systems. To facilitate understanding the fundamental concepts of lightweight floor vibrations for serviceability design, a newly proposed damped plate-oscillator model was adopted in this research to predict dynamic responses of cold-formed steel floors induced by human walking. Three loading methods were developed based on this model. By using these loading methods, comprehensive parametric studies involving step frequencies, mass ratios, damping ratios, walking paths and end-support restraints were conducted. The present analytical studies show that the influence of moving or stationary occupants depends on the mass ratio of occupants to the floor and its significance could be negligible for small mass ratios. In addition, the boundary restraints at floor end-supports may not always reduce floor responses. On the contrary, relatively larger responses could be excited by human walking for the restrained floors having the fundamental frequency close to the multiple of the footstep frequency.

scholarly journals Experimental studies on changes in mechanical properties of polymer composites under impact of thermal load determined based on compression testing

2018 ◽  
Vol 247 ◽  
pp. 00027
Author(s):  
Agata Walczak ◽  
Ireneusz Naworol ◽  
Daniel Pieniak ◽  
Kamil Pasierbiewicz ◽  
Grzegorz Dzień
Keyword(s):  
Mechanical Properties ◽  
Polymer Composites ◽  
Thermal Load ◽  
Experimental Studies ◽  
Thermal Exposure ◽  
Protective Properties ◽  
Trade Name ◽  
Young Module ◽  
In Fire ◽  
Compressive Tests

The objective of the study was to carry out an analysis of changes in mechanical properties of polymer composites in conditions of thermal load. Such an analysis may allow an initial verification of possibilities of deploying new composites in production of fire helmet shells. The reference material chosen for testing was the Ultramid composite, which is currently used for the production of fire helmet shells. In addition three different materials were selected that contained reinforcement by glass fibres bearing the trade name of Tarnamid, which are not used in manufacturing of shells. Testing was conducted in conditions of quasi-static load, during which compressive tests were performed. Mechanical loads were applied at different levels of thermal exposure, which was to simulate presence in fire conditions. Results of tests indicated that the Tarnamid composites are characterised by better compressive strength and rigidity determined on the basis of the Young module value than Ultramid PA66 GF25 used in the production of head protective shells. It has also been proven that thermal loads contribute to significant degradation in strength and rigidity of tested materials, which affects adversely protective properties of the helmet.

NUMERICAL ANALISYS OF COLD-FORMED STEEL COLUMNS WITH FIRE PROTECTION IN FIRE SITUATION

2017 ◽  
Author(s):  
Marina Machado Leal dos Santos ◽  
Tiago Ancelmo de Carvalho Pires de Oliveira ◽  
José Jéferson do Rêgo Silva
Keyword(s):  
Fire Protection ◽  
Steel Columns ◽  
Cold Formed Steel ◽  
In Fire

System Reliability Benefits of Repetitive Framing in Cold-Formed Steel Floor Systems

2018 ◽  
Vol 144 (6) ◽  
pp. 04018061 ◽  
Author(s):  
Brooks H. Smith ◽  
Aritra Chatterjee ◽  
Sanjay R. Arwade ◽  
Cristopher D. Moen ◽  
Benjamin W. Schafer
Keyword(s):  
System Reliability ◽  
Floor Systems ◽  
Cold Formed Steel

scholarly journals Serviceability and flexural strength of lightweight floor made of cold formed steel joists.

2021 ◽  
Author(s):  
Quzzafi Rehman
Keyword(s):  
Finite Element ◽  
Flexural Strength ◽  
Ultimate Strength ◽  
Parametric Study ◽  
Finite Element Modelling ◽  
Dynamic Properties ◽  
Element Modelling ◽  
Floor Systems ◽  
Cold Formed Steel ◽  
Experimental Findings

The use of cold-formed steel (CFS) is becoming popular in residential and commercial building as a cost-effective alternative to traditional wood materials. CFS provides high strength-to-weight ratio, resulting in permitting lighter structure and longer spans. If proper design considerations are not made, this longer span and lighter structure can result in vibration serviceability issues that may affect building occupant comfort. The available design methods to calculate the dynamic properties of floor systems (i.e. Canadian Wood Council Method, CWC; Applied Design Council Design Method, ATC; and Eurocode, EC5) are used for the design of light-frame timber-based systems, CFS C-shape joists, and structural steel and concrete floor systems. The applicability of such methods to I-shape CFS joists is as yet unavailable. In addition, the North American Code for Cold-formed Steel structural Members (CSA-S136-07) provides specifications of ultimate and serviceability limit state design of C-shape joists rather than I-shape joists. As such, this research was divided into three parts. Part 1 presented the results of laboratory and field study on the vibration of a recently developed CFS I-shape joist called “iSPAN.” The main objective of the first part was to understand the dynamic characteristics of iSPAN floor system, recommend an adequate model for predicting the dynamic response and modal properties of floor systems, and correlate its results with engineered wood I-joists in order to aid the design process. Part 2 presented comparison between the experimental findings and available code provisions for the design of CFS joists at ultimate and serviceability limit states. The effect of web utility holes was also considered on the dynamic properties, and ultimate strength of iSPAN joists. Part 3 presented a finite-element modeling and its verification with the experimental findings of the tested samples. Also, part 3 extended the finite element modelling to analyse I- and C-shape CFS joists to determine their ultimate strength and serviceability, with and without the presence of utility holes in the webs. Since CSA-S137-07 does not provide design provisions for the edge-stiffened (i.e. lipped) holes, a practical-design-oriented parametric study, using the finite-element modelling, was conducted on CFS I- and C-shape members with circular, slotted and tri-slotted, edge-stiffened, holes under flexural loading. The optimized profile of the edge-stiffened holes was obtained using the elastic-buckling analysis. The post-buckling finite-element analysis was then utilized to determine member flexural strength as affected by utility hole geometry and web depth. Results showed that the edge-stiffened holes can significantly improve the flexural strength of CFS joists. The data generated from the parametric study was used to develop new design provisions to predict the flexural strength of such joists with the presence of edge-stiffened holes.

Vibration of cold-formed steel floors with a steel form deck and gypsum-based self-leveling underlayment

2019 ◽  
Vol 22 (13) ◽  
pp. 2741-2754
Author(s):  
Yu Guan ◽  
Xuhong Zhou ◽  
Xinmei Yao ◽  
Yu Shi
Keyword(s):  
Finite Element ◽  
Fundamental Frequency ◽  
Damping Ratio ◽  
Point Load ◽  
Element Analysis ◽  
Static Tests ◽  
Floor Systems ◽  
Cold Formed Steel ◽  
Center Deflection ◽  
Deflection Limit

The vibration response and static deflection of cold-formed steel floor systems with a form deck and gypsum-based self-leveling underlayment were investigated through an experimental study and a finite element analysis. The floor system was constructed with cold-formed steel joists as supports and a cold-formed steel form deck subfloor with gypsum-based self-leveling underlayment on the surface. Dynamic tests and 1 kN static tests were carried out on three specimens, and design specifications including shear resistance construction and floor width were varied to explore their effects on the fundamental frequency, damping ratio, and center deflection of floors. Then, finite element models were developed and verified with the experimental test results, and parametric studies were conducted to consider the effect of boundary conditions on the vibration performance of the same floor systems. Based on the result, a minimum limit of fundamental frequency of 10 Hz and a maximum center deflection limit under a 1 kN point load of 1 mm were recommended for cold-formed steel floor systems with a form deck and gypsum-based self-leveling underlayment. Finally, methods to calculate the fundamental frequency and center deflection of this floor systems were proposed.

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