Analytical Method for the Bending Resistance of Slim Floor Beams with Asymmetric Double-T Steel Section under ISO Fire

The slim floor beams, characterized by the steel profile embedded in the concrete slab, may be found in different configurations, based on the shape of the steel profile cross-section, which can vary from a rectangular to double-T section. While the most common shape used nowadays is the double-T cross-section, the Eurocodes do not provide a simplified method for the fire resistance assessment. The literature offers a simplified method for computation of bending resistance under elevated temperature, based on existing research on thermal models, and was validated for a particular type of slim floor beams (SFB). The current study extends the scope of application of this method, for different types of slim floor beam, which include an asymmetric double-T steel cross-section. The objective was reached through a numerical procedure, by analyzing 162 configurations subjected to four different fire requirements (R30, R60, R90, R120), resulting in a total of 648 analyses, performed with a validated numerical model in SAFIR software. The results in terms of bending resistance showed that the simplified method represents a strong tool for the fire design of slim floor beams.

Compare Among Methods for Re-Habitation Damaged Concrete Beams-Ferrocement, Steel, FCRP and Nano-Materials Sections

The complicated and costly of concrete structures as well as the exposure to risk, owing to several factors such as ecological, design and construction, has resulted in a wide variety of methods for residential concrete structures, such as ferrocement sections technology, steel section technology, FCRP technology, and nano-material technologies. In this article the four approaches employed for rehabilitation of damaged concrete were compared. The questionnaire is given to 100 construction engineers and project management professionals to determine their preferred methods and advise them on their strength, effort, time and cost. To confirm the results, the researcher conducted an experiment to compare among these methods. research result, recommendations for future research, and conclusions were discussed in detail.

Analysis of Non-Symmetrical Heat Removal during Cast-ing of Steel Billets and Slabs

Steel is one of the essential materials in the world's civilization. It is essential to produce many products such as pipelines, mechanical elements in machines, vehicles, profiles, and beam sections for buildings in many industries. Until the '50s of the 20th century, steel products required a complex process known as ingot casting; for years, steelmakers focused on developing and simplifying this process. The result was the con-tinuous casting process (CCP); it is the most productive method to produce steel. The CCP allows producing significant volumes of steel sections without interruption and is more productive than the formal ingot casting process. The CCP begins by transferring the liquid steel from the steel-ladle to a tundish. This tundish or vessel distributes the liquid steel, by flowing through its volume, to one or more strands having wa-ter-cooled copper molds. The mold is the primary cooling system, PCS, solidifying a steel shell to withstand a liquid core and its friction forces with the mold wall. Further down the mold, the rolls drive the steel section in the SCS. Here the steel section is cooled, solidifying the remaining liquid core, by sprays placed in every cooling segment all around the billet and along the curved section of the machine. Finally, the steel strand goes towards a horizontal-straight free-spray zone, losing heat by radiation mechanism, where the billet cools down further to total solidification. A moving torch cutting-scissor splits the billet to the desired length at the end of this heat-radiant zone.

Structural parameters analysis for tapered steel section with perforation: effect of shear buckling behaviour

Purpose Due to economic development, tapered members are commonly applied in steel frames, namely, industrial halls, warehouses, exhibition centres, etc. In the design of cantilever steel beam structures in cities building design, tapering is introduced at the web profile to achieve utmost economy and suit the bending moment distributions. The cross-sectional shape of the beam is varied linearly to the moment gradient to achieve the target of higher efficiency with lower cost. Design/methodology/approach The shear deformation pattern and efficiency of the tapered steel section with perforation were investigated using finite element analysis. In addition, I-beam with web opening is studied numerically via LUSAS software for different parameters of tapering ratio, perforation shape and perforation size and perforation layout. Findings The highest contributing parameters for the highest shear buckling capacity and efficiency of the section were due to the small opening size and tapering ratio. Whilst the variation of perforation layout and spacing give a major effect on the shear strength and efficiency of the tapered steel section with perforation. Besides that, the highest efficiency model is found when the section is designed with 0.4 D diamond perforation in Layout 3 under a tapering ratio of 0.3. The critical shear buckling load and efficiency is reduced 14.39% and 13.91%, respectively, when perforations are added onto the tapered steel sections. Originality/value The tapered steel section with perforation has lower critical shear buckling load and efficiency compared to the tapered section without perforation but obtains a higher critical shear buckling load and efficiency compared to the uniform section without perforation.

BEHAVIOR OF PARTIAL STRENGTH OF BEAM-TO-COLUMN CONNECTION WITH GUSSET PLATE FOR COLD-FORMED STEEL SECTIONS

The use of cold-formed steel (CFS) as part of a major construction has been rapidly increasing recently, as it is considered viable as an alternative to the conventional hot-rolled steel section. However, information about CFS as part of a non-composite system is still limited as the connection is designed as a pinned connection, only good for roof trusses and wall paneling. The aim of this research is to propose a connection for CFS sections that could enhance the strength of typical CFS connections, from pinned to partial strength connections. This paper presents the behavior of the partial strength of a non-composite beam-to-column connection for a cold-formed steel section where a gusset plate was used as a stiffener. This type of proposed connection for CFS is not limited only to the construction of roof trusses and wall cladding, but is also able to provide better flexural strength in semi-continuous construction. The proposed connections consisted of 6 specimens divided into two types, the first of which were stiffened by the gusset plate and the second of which were enhanced further with the top, seat and web angles. From the results of the experimental tests it was concluded that all the proposed connections can be categorized as partial strength connections, where the strength was more than 25% of the connected beam and suitable for use in semi-continuous construction. A relatively good agreement was recorded for the comparison between the experimental results and the predicted results from the EC3 component method super-imposed with a haunched gusset plate and top, seat and web angle components, which differed in the range of 1.31 to 1.5 times for the moment resistance and 1.07 to 1.37 times for the stiffness of the proposed connections.

The capacity analysis of wide flange steel section as beam-column elements

The design of the steel frame structure for beam, column, and beam-column elements usually takes several iterations to obtain optimum results that are safe, efficient, and economical. The problems that arise due to the number of iteration for the design process are the basis for this research. The research was conducted on 100 sections IWF and HCS which are consisted of 81 sections of IWF and 19 sections of HCS. The analysis was carried out regarding SNI 1729:2015. The results of this study are in the form of moment capacity graphs and tables of the axial capacity of steel sections as well as coefficients of m and U for beam-column design. Moment capacity graphs and tables of the axial capacity of IWF and HCS profiles produced could be used to reduce the number of iteration in designing safe and efficient steel profiles as beam, column, and beam-column elements. Analysis results show that the usage of the graphs and tables for the beam-column design process will reduce the number of iteration needed.

Analisis Perilaku Balok Kastella Dengan Variasi Jenis Bukaan

The main advantage of castellated beam is the increasing of bending capacity caused by the increasing of inertia moment of steel section due to the increasing of depth of the steel section. In addition, some people argue that the opening section of castellated beam become an additional advantage in terms of aesthetics view. In general, there are three opening variations that are very often used in construction, which are hexagonal opening, circular opening, and diamond opening. Many researches have been done to compare the performance of castellated beam with various opening but only focusing on the behavior of castellated beam subjected to monotonic loading. Therefore, in this research, a review of the behavior of castellated beam with various opening subjected to quasi-static cyclic loading was carried out in order to find out which is better performance from the opening variations. A finite element analysis was conducted to find out the behavior of castellated beam with three variations of opening. A simple beam subjected to quasi-static loading using displacement control technique was considered in this research. The result shows that the castellated beam with diamond opening has a better performance compared to the other openings (hexagonal opening and circular opening).