scholarly journals ANALISIS PENGARUH JENIS DAN TEBAL SPRAY APPLIED MATERIALS FIREPROOFING TERHADAP KETAHANAN API BALOK BAJA

2017 ◽  
Vol 14 (1) ◽  
pp. 1
Author(s):  
NKA Agustini ◽  
Andreas Triwiyono
Keyword(s):  
Yield Stress ◽  
Numerical Approach ◽  
Nonlinear Material ◽  
Constant Thickness ◽  
Thickness Variation ◽  
Steel Beams ◽  
Steel Beam ◽  
Structural Elements ◽  
Eurocode 3 ◽  
Thick Steel

Protection against fire is important to maintain the strength of the structure. Fireproofing can be used as an anticipation to reduce the spread of the fire. Evaluation the effect of fire on structural elements is generally performed by a numerical approach. Analysis of simple beam IWF 150x75x5x7 with 3,5 span length using varied fireproofing such as CAFCO 300, Carboline Type 5 MD and Typo WR-AFD was conducted with Abaqus CAE 6.11-1. Nonlinear material properties of steel based on Eurocode 3 while thermal properties of fireproofing are constant. Thickness variation of fireproofing are 10 and 20 mm. Pressure load was carried on the top flange of steel beam. ASTM E-119 used as a thermal load by conduction on 3 sides (left, right and bottom) with duration of 2 hours.  The results showed that type and thickness variation of the fireproofing has a significant effect on the fire resistance of steel beams. The highest temperatures occur when steel coated by Typo WR-AFP and the lower temperatures occur when steel coated by CAFCO 300. Maximum deflection of steel beam occurred when steel coated by Typo WR-AFD. Steel beam with Typo WR-AFD experiencing a critical deflection with the fastest time of 4.80 minutes at 10 mm thick and 9.10 min at 20 mm thick. Steel beam with 10 mm thick of fireproofing achieve yield stress when the time 14.03, 8.86 and 5, 12 minutes for fireproofing CAFCO 300, Carboline Type 5 MD and Typo-AFD WR. Steel beam with 20 mm thick of fireproofing  experiencing yield stress only on Typo WR-AFD at 10.22 minutes.  Abstrak : Perlindungan terhadap api (kebakaran) merupakan hal penting untuk mempertahankan kekuatan struktur sehingga masih dapat menahan beban rencana. Lapisan fireproofing pabrikasi dapat digunakan sebagai antisipasi untuk mengurangi rambatan panas akibat kebakaran. Evaluasi pengaruh kebakaran pada elemen struktur umumnya dilakukan dengan pendekatan numerik. Analisis pengaruh ketebalan dan sifat termal fireproofing jenis spray applied materials bervariasi yaitu CAFCO 300, Carboline Type 5MD dan Typo WR-AFD terhadap ketahanan api balok sederhana IWF 150x75x5x7 menggunakan Abaqus CAE 6.11. Material baja bersifat non linier sesuai Eurocode 3 sedangkan sifat termal fireproofing bersifat konstan. Variasi ketebalan lapisan digunakan 10 dan 20 mm. Beban tekan (pressure loads) dikerjakan di sayap atas balok. Beban termal menggunakan standar api ASTM E-119 secara konduksi di 3 sisi (samping kiri, kanan dan bawah) dengan durasi 2 jam. Hasil penelitian menunjukkan variasi jenis dan ketebalan fireproofing memberikan pengaruh signifikan terhadap ketahanan api balok baja. Suhu baja tertinggi terjadi saat baja dilapisi fireproofing jenis TYPO WR-AFP dan terendah saat dilapisi fireproofing CAFCO 300. Baja dengan lapisan fireproofing TYPO menghasilkan lendutan paling besar dibanding baja dengan lapisan fireproofing lainnya Baja dengan lapisan fireproofing Typo WR-AFD mengalami lendutan kritis dengan waktu tercepat yakni 4,80 menit saat tebal 10 mm dan 9,10 menit tebal 20 mm Baja dengan lapisan fireproofing 10 mm mencapai tegangan leleh saat waktu 14,03 , 8,86 dan 5, 12 menit untuk fireproofing CAFCO 300, Carboline Type 5 MD dan Typo WR-AFD. Baja dengan tebal fireproofing 20 mm mengalami tegangan leleh hanya pada jenis Typo WR-AFD saat 10,22 menitKata kunci :jenis fireproofing,  tebal fireproofing, temperatur, lendutan, tegangan.

scholarly journals Comparação entre a eficiência estrutural de perfis soldados de aço e perfis de aço formados a frio

2016 ◽  
Vol 12 (3) ◽  
Author(s):  
Uiatan Aguiar Nogueira ◽  
Matilde Batista Melo ◽  
Daniel De Lima Araujo
Keyword(s):  
Bending Strength ◽  
Steel Beams ◽  
Steel Beam ◽  
Structural Elements ◽  
Structural System ◽  
Welded Steel ◽  
Bending Tests ◽  
Structural Efficiency ◽  
Cold Formed Steel

RESUMO: A Análise de elementos estruturais, realizadas durante as etapas de projeto de uma estrutura, é parte fundamental para garantia de bom desempenho e estabilidade do sistema estrutural. Na execução de algumas estruturas, como as coberturas em edificações, é usual o emprego de perfis leves de aço formados a frio devido ao seu baixo peso. Esta pesquisa tem por objetivo avaliar a eficiência estrutural desses perfis quando comparados, por exemplo, aos perfis soldados compactos. Para tanto, foram realizados ensaios de flexão em quatro vigas biapoiadas submetidas a duas forças concentradas, de forma a se obter flexão pura no meio do vão das vigas. Estas foram instrumentadas para a determinação da sua rigidez e da sua resistência à flexão. A principal contribuição deste trabalho é demonstrar a eficiência estrutural de perfis formados a frio em seção caixa submetidos à flexão em comparação com perfis de seção tipo “H” soldados. ABSTRACT: The analysis of structural elements, in a structure’s design, is an essential step to ensure good performance and stability of the structural system. In any types of structures, such as roofing in buildings, it’s usual using cold-formed steel beams due to their small weight. This research seeks to evaluate the structural efficiency of cold-formed steel beams when compared, for example, to compact welded steel beams. Thus, bending tests were performed in four simply supported beams submitted to two concentrated loads, in order to obtain pure flexure at the mid-span of the beams. These beams were instrumented for the determination of their rigidity and bending strength. The results showed that the cold-formed steel beam, box-shaped, presented structural efficiency similar to the welded steel beam “H” shaped.

scholarly journals Análise de uma Estrutura de Concreto Armado e proposição de reforço para correção de falhas estruturais: Estudo de Caso

2018 ◽  
Vol 1 (43) ◽  
pp. 140
Author(s):  
Gláucia Nolasco de Almeida Mello ◽  
Bárbara Elisa Ferreira ◽  
Marina R. B. Macedo ◽  
Carolina S. Oliveira ◽  
Marina X. S. Assis ◽  
...  
Keyword(s):  
Natural Frequencies ◽  
Steel Beams ◽  
Steel Beam ◽  
Reinforced Concrete Structures ◽  
Vibration Modes ◽  
Structural Elements ◽  
Static And Dynamic Analysis ◽  
Critical Range ◽  
Useful Life ◽  
Recurrent Process

The reinforced concrete structures degradation even before reaching useful life, is a very recurrent process in buildings, and it is necessary to execute corrective techniques to strengthen the structural elements. Therefore, it is noted that research in this field is very important to civil engineering. Consequently, the present study consisted in performing a static and dynamic analysis of a school building that presented structural flaws to identify the causes of it and propose a rehabilitation solution. Through the static analysis of the structure, performed with the CAD/TQS program, it was verified that the slabs and beams of the building were mostly executed with a thickness lower than ideal and that, in some slabs, the deflection obtained were higher than allowable. Through modal analysis, performed with Altair HyperWorks program, it was verified that the fourth, fifth and sixth vibration modes of the structure did not meet the ELS-VE, since they present natural frequencies between the critical range indicated by NBR 6118 (ABNT, 2014), thus showing the occurrence of excessive vibration. As a result, a rehabilitation solution was proposed, using steel beams, which were calculated according to the methodology of NBR 8800 (ABNT, 2008) and, verified with the aid of Altair HyperWorks program. This methodology for strengthening the concrete structure was verified with the aid of the platform Altair HyperWorks, where it was concluded that the steel beam used are able to solve the problem with the excessive deflection in the slabs without harming the displacements of the beans who support them, maintaining unaltered the natural frequencies.

scholarly journals Studying the performance of fully encapsulated rock bolts with modified structural elements

2021 ◽  
Author(s):  
Jianhang Chen ◽  
Hongbao Zhao ◽  
Fulian He ◽  
Junwen Zhang ◽  
Kangming Tao
Keyword(s):  
Shear Stress ◽  
Load Transfer ◽  
Maximum Shear Stress ◽  
Coupling Model ◽  
Numerical Approach ◽  
Rock Bolt ◽  
Structural Elements ◽  
Rock Bolts ◽  
Two Stage ◽  
Bolt Diameter

AbstractNumerical simulation is a useful tool in investigating the loading performance of rock bolts. The cable structural elements (cableSELs) in FLAC3D are commonly adopted to simulate rock bolts to solve geotechnical issues. In this study, the bonding performance of the interface between the rock bolt and the grout material was simulated with a two-stage shearing coupling model. Furthermore, the FISH language was used to incorporate this two-stage shear coupling model into FLAC3D to modify the current cableSELs. Comparison was performed between numerical and experimental results to confirm that the numerical approach can properly simulate the loading performance of rock bolts. Based on the modified cableSELs, the influence of the bolt diameter on the performance of rock bolts and the shear stress propagation along the interface between the bolt and the grout were studied. The simulation results indicated that the load transfer capacity of rock bolts rose with the rock bolt diameter apparently. With the bolt diameter increasing, the performance of the rock bolting system was likely to change from the ductile behaviour to the brittle behaviour. Moreover, after the rock bolt was loaded, the position where the maximum shear stress occurred was variable. Specifically, with the continuous loading, it shifted from the rock bolt loaded end to the other end.

scholarly journals Reliability of beams designed in accordance with Brazilian codes

2014 ◽  
Vol 7 (5) ◽  
pp. 723-746 ◽  
Author(s):  
D. M. Santos ◽  
F. R. Stucchi ◽  
A. T. Beck
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Composite Beams ◽  
Reinforced Concrete Beams ◽  
Steel Beams ◽  
Structural Elements ◽  
Pure Bending ◽  
Design Standards ◽  
Limit Values ◽  
Relative Safety

This paper presents an investigation on the safety of structural elements submitted to pure bending, produced in reinforced concrete, in steel and steel-concrete composites, and designed according to Brazilian codes NBR8681:2003, NBR6118:2007 and NBR8800:2008. The study allows a comparison of the relative safety of beams produced with these materials and designed using these codes. Comparative studies between the performances of different materials are difficult to find in the published literature. The present study shows that reliability indexes for reinforced concrete beams are satisfactory; however, results for steel beams are below limit values established in international design standards. Reliability indexes found herein for steel-concrete composite beams are intermediate to concrete and steel beams.

scholarly journals Seismic Behavior and Study of RCS Composite Frame Composed of Steel Beams and Strong Concrete Column

2019 ◽  
Vol 15 (2) ◽  
pp. 142-153
Author(s):  
Ahmadreza Khodabandehlo ◽  
Mohamad Taghi Kazemi
Keyword(s):  
Reinforced Concrete ◽  
Seismic Behavior ◽  
Bending Strength ◽  
Steel Beams ◽  
Steel Beam ◽  
Concrete Column ◽  
Moment Frame ◽  
Reinforced Concrete Column ◽  
Long Span ◽  
Composite Frame

AbstractWith spreading of population and increasing of instruction, and also because of limited resources and materials, the demand for using novel materials in building industry has increased. The reinforced concrete columns and steel beams are used in structures with composite moment frame (RCS). Use of compression strength in proportion with concrete and bending strength of steel beam has bestowed these structures less weight than that of concrete structures and made it easier to access the measure of strong column - weak beam especially within long span in these structures. The most important part of these structures is connection of steel beam with the reinforced concrete column. These connections are divided into two general groups of connection with bracing beam and with bracing column from the joint. This paper aims to study the seismic behavior and parameters of RCS composite frame composed of steel beams and strong concrete column. The finite element method was analyzed by ABAQUS software and data analyzed by Excel.

scholarly journals A comparative study of beam design curves against lateral torsional buckling using AISC, EC and SP

2019 ◽  
Vol 15 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Vera V Galishnikova ◽  
Tesfaldet H Gebre
Keyword(s):  
Steel Structures ◽  
Reduction Factor ◽  
Steel Beams ◽  
Steel Beam ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Vertical Loading ◽  
Beam Design ◽  
Overall Stability

Introduction. Structural stability is an essential part of design process for steel structures and checking the overall stability is very important for the determination of the optimum steel beams section. Lateral torsional buckling (LTB) normally associated with beams subject to vertical loading, buckling out of the plane of the applied loads and it is a primary consideration in the design of steel structures, consequently it may reduce the load currying capacity. Methods. There are several national codes to verify the steel beam against LTB. All specifications have different approach for the treatment of LTB and this paper is concentrated on three different methods: America Institute of Steel Construction (AISC), Eurocode (EC) and Russian Code (SP). The attention is focused to the methods of developing LTB curves and their characteristics. Results. AISC specification identifies three regimes of buckling depending on the unbraced length of the member ( Lb ). However, EC and SP utilize a reduction factor (χ LT ) to treat lateral torsional buckling problem. In general, flexural capacities according to AISC are higher than those of EC and SP for non-compact sections.

On a Simplified Method for Solving Impulsively Loaded Structures of Rate-Sensitive Materials

1965 ◽  
Vol 32 (3) ◽  
pp. 489-492 ◽  
Author(s):  
Nicholas Perrone
Keyword(s):  
Yield Stress ◽  
Rate Sensitivity ◽  
Approximate Solutions ◽  
Exponential Rate ◽  
Structural Elements ◽  
Sensitive Material ◽  
Perfectly Plastic ◽  
Simplified Method ◽  
Dynamic Yield ◽  
Constant Yield

In an attempt to assess more completely rate-sensitive material effects, two fundamental structural elements are analyzed: A wire with an impulsively loaded end mass, and an impulsively loaded ring. The ring and wire are made of perfectly plastic, rate-sensitive materials. In each case, exact and approximate solutions are obtained for an exponential rate-sensitivity law. The results suggest that very good approximations to the exact solutions may be found by utilizing a rate-insensitive material with constant yield stress equal to the initial dynamic yield stress.

Interactive shear resistance of corrugated web in steel beam exposed to fire

2016 ◽  
Vol 7 (1) ◽  
pp. 69-78
Author(s):  
Mariusz Marcin Maslak ◽  
Marcin Lukacz
Keyword(s):  
Failure Modes ◽  
Steel Beams ◽  
Steel Beam ◽  
Safety Level ◽  
Design Algorithm ◽  
Content Type ◽  
Corrugated Webs ◽  
Buckling Resistance ◽  
Corrugated Web ◽  
Shear Buckling

Purpose The purpose of this paper is to present and discuss in detail the design approach to shear buckling resistance evaluation for corrugated web being a part of a steel beam exposed to fire. Design/methodology/approach It is based on the interaction between the local and global elastic instability failure modes as well as on the possible yielding of the whole web cross-section during fire. Findings New formulae, adequate for specification of the suitable shear buckling coefficients, depend not only on the web slenderness but also on the temperature of structural steel. Originality/value The methodology proposed by the authors can be added to the current European standard recommendations given in EN 1993-1-2 as a well-justified design algorithm helpful in reliable evaluation of a safety level for steel beams with slender corrugated webs subject to fire exposure. It seems to be highly desirable because, at present, there are no detailed instructions in this field.

Experimental study on vertical vibration characteristics of medium-low speed maglev vehicle when standing still on steel beams

2021 ◽  
pp. 095440972110324
Author(s):  
Miao Li ◽  
Xiaohao Chen ◽  
Shihui Luo ◽  
Weihua Ma ◽  
Cheng Lei ◽  
...  
Keyword(s):  
Coupled System ◽  
Vertical Vibration ◽  
Vibration Characteristics ◽  
Steel Beams ◽  
Steel Beam ◽  
Air Spring ◽  
Low Speed ◽  
Maglev Vehicle ◽  
Excited Vibration ◽  
Eigen Frequencies

Levitation stability is the very basis for the dynamic operation of Electromagnetic Suspension (EMS) medium-low speed maglev trains (MSMT). However, self-excited vibration tends to occur when the vehicle is standing still above the lightweight lines, which remains a major constraint to the promotion of medium-low speed maglev technology. In order to study the vertical vibration characteristics of the coupled system of MSMT when it is standing still above lightweight lines, levitation tests were carried out on two types of steel beams: steel beam and active girder of the turnout, with a newly developed maglev vehicle using levitation frames with mid-set air spring. Firstly, modal tests were carried out on the steel beam to determine its natural vibration characteristics; secondly, the acceleration signals and the dynamic displacement signals of the air spring obtained at each measurement point were analyzed in detail in both the time and frequency domains, and the vertical ride comfort was assessed by means of the calculated Sperling index. Subsequently, theoretical explanations were given for the occurrence of self-excited vibration of coupled system from the perspective of the vehicle-to-guideway vibration energy input. Results show that the eigen frequencies of the vehicle on the steel beam and the turnout are 9.65 Hz and 2.15 Hz, respectively, the former being close to the natural frequency of the steel beam while the latter being close to the natural frequency of the air spring suspension system, thus causing the self-excited vibration of the coupled system. It is recommended to either avoid the main eigen frequencies of the coupled system or to increase the damping of the corresponding vibration modes to guarantee a reliable coupled system for its long-term performance. These results may provide valuable references for the optimal design of medium-low speed maglev systems.

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