Influences of Concentric and Eccentric Loads on Buckling of Fixed-End Supported Pultruded FRP Channel Beams

2015 ◽  
Vol 1119 ◽  
pp. 721-725 ◽  
Author(s):  
Jaksada Thumrongvut ◽  
Sittichai Seangatith
Keyword(s):  
Research Work ◽  
Geometrically Nonlinear ◽  
Cross Sectional ◽  
Modes Of Failure ◽  
Cross Sectional Dimension ◽  
Center Position ◽  
The Cross ◽  
Flexural Torsional Buckling ◽  
Fixed End ◽  
Structural Behaviors

This paper presents the results of the experimental research performed on the pultruded FRP (PFRP) channel beams subjected to transversely concentric and eccentric loads. The objectives of the research work are to investigate their structural behaviors and to determine the critical buckling moments and modes of failure of the beams with various span-to-depth ratios and eccentricities. Pultruded beams are fixed-end supported at both ends for major and minor-axis flexure. The beam specimens have the cross-sectional dimension of 102×29×6 mm with span-to-depth ratios, ranging from 20 to 40. A total of 40 mono-symmetric section tests were performed. The effects of vertical load position through the cross-section were studied. Also, shear center position with concentric load and three different eccentricities were investigated ranging from 0 to-3e. The specimens were tested to final buckling. Based upon the results of this study, it is found that the load versus mid-span vertical deflection relationships of the beams are linear up to the failure. On the contrary, the load versus mid-span lateral deflection relationships are geometrically nonlinear. The general mode of failure is the flexural-torsional buckling. The eccentrically loaded specimens are failed at buckling loads lower than their concentric counterparts. Overall, the critical buckling moment decreases as the magnitude of eccentricity increases. Additionally, it is noticed thatL/dratio increases, the critical buckling moment is decreased.

Experimental Evaluation on Fixed End Supported PFRP Channel Beams and LRFD Approach

2011 ◽  
Vol 105-107 ◽  
pp. 1671-1676 ◽  
Author(s):  
Jaksada Thumrongvut ◽  
Sittichai Seangatith
Keyword(s):  
Experimental Results ◽  
Geometrically Nonlinear ◽  
Vertical Deflection ◽  
Torsional Buckling ◽  
Cross Sectional ◽  
Modes Of Failure ◽  
Flexural Torsional Buckling ◽  
Fixed End ◽  
Structural Behaviors ◽  
Steel Design

In this paper, the experimental results on the fixed end supported PFRP channel beams subjected to three-point loading are presented. The aims of this study are to evaluate the effects of the span (L) on the structural behaviors, the critical buckling moments and the modes of failure of the beams, and to compare the obtained critical buckling moments with those obtained from the modified LFRD steel design equation in order to check the adequacy of the equation. The beam specimens have the cross-sectional dimensions of 76x22x6 mm, with span-to-depth ratio (L/d) ranging from 13 to 52. A total of twenty-six specimens were tested. Based on the experimental results, it was found that the loads versus mid-span vertical deflection relationships of the beams are linear up to the failure. On the contrary, the load versus mid-span lateral deflection relationships are geometrically nonlinear. The general modes of failure are the flexural-torsional buckling. Finally, the modified LFRD equation can satisfactorily predict the critical buckling moment for L/d exceeds 20. However, for L/d < 20, the equation overestimates the critical buckling moment of the beams and more development is needed.

Experimental Investigation on Simply Supported PFRP Channel Beams Subjected to Three-Point Loading

2011 ◽  
Vol 335-336 ◽  
pp. 1321-1326 ◽  
Author(s):  
Sittichai Seangatith ◽  
Jaksada Thumrongvut
Keyword(s):  
Research Work ◽  
Geometrically Nonlinear ◽  
Test Results ◽  
Cross Sectional ◽  
Simply Supported ◽  
Modes Of Failure ◽  
Mode Of Failure ◽  
General Mode ◽  
Flexural Torsional Buckling ◽  
Steel Design

This paper presents the experimental results on the simply supported PFRP channel beams subjected to three-point loading. The objectives of the research work are to investigate the effects of the span (L) of the beams on the behaviors, the critical buckling moments and the modes of failure of the beams, and to compare the obtained critical buckling moments with those obtained from the modified LFRD steel design equation in order to check the adequacy of the equation. The beam specimens have the cross-sectional dimensions of 102×29×6 mm with span-to-depth ratio (L/d) ranging from 20 to 40. A total of ten specimens were tested. Based on the test results, it was found that the load versus mid-span vertical deflection relationships are linear up to the failure, but the load versus mid-span lateral deflection relationships are geometrically nonlinear. The general mode of failure is the flexural-torsional buckling. Finally, the modified LFRD equation can satisfactorily predict the critical buckling moment of the PFRP beams used in this study.

An Experimental Study on the Performance of Fixed-End Supported PFRP Channel Beams under Flexure

2013 ◽  
Vol 702 ◽  
pp. 31-36 ◽  
Author(s):  
Jaksada Thumrongvut ◽  
Sittichai Seangatith
Keyword(s):  
Shear Deformation ◽  
Beam Theory ◽  
Beam Equation ◽  
Vertical Deflection ◽  
Cross Sectional ◽  
Modes Of Failure ◽  
Theory Equation ◽  
Flexural Torsional Buckling ◽  
Fixed End ◽  
Structural Behaviors

The experimental investigation on the fixed-end supported PFRP channel beams subjected to three-point loading is presented. The objectives of this study are to evaluate the effects of the span on the structural behaviors, the critical buckling loads and the modes of failure of the PFRP beams, and to compare the obtained deflections with those obtained from the Timoshenko’s shear deformation beam theory equation in order to check the adequacy of the equation. The beam specimens have the cross-sectional dimensions of 152 43 10 mm with span-to-depth ratio ranging from 16 to 33. A total of twenty-two specimens were performed. Based on the experimental results, it was found that the loads versus mid-span vertical deflection relationships of the beam specimens are linear up to the failure, but the load versus mid-span lateral deflection relationships are geometrically nonlinear. The general modes of failure are the flexural-torsional buckling. Finally, the Timoshenko’s shear deformation beam equation can satisfactorily predict the vertical deflection of the beams within acceptable engineering error.

Experimental Investigation on Axially Loaded PFRP Compression Members Having Double C-Sections

2014 ◽  
Vol 548-549 ◽  
pp. 510-514
Author(s):  
Sittichai Seangatith ◽  
Jaksada Thumrongvut ◽  
Chanon Chatwiwat
Keyword(s):  
Experimental Investigation ◽  
Research Work ◽  
Test Results ◽  
Cross Sectional ◽  
Modes Of Failure ◽  
Linear Behavior ◽  
Compression Members ◽  
Axially Loaded ◽  
Structural Behaviors ◽  
Structural Plastics

This paper presents the results of an experimental investigation on axially loaded PFRP compression members having double C-sections with pinned-pinned supports. The objectives of this research work are to investigate their structural behaviors and modes of failure and to propose their design equations. The specimens were built from single PFRP C-section, having three cross-sectional dimensions of 76×22×6 mm, 102×29×6 mm and 152×43×10 mm. A total of 42 specimens with slenderness ratios ranging from 21 to 168 were tested. The compression members can be classified as short and long. The short compression members have linear behavior up to 90% to 95% of the ultimate crushing loads. The long compression members have linear behavior up to 80-90% of the flexural buckling loads. By comparing and fitting the test results with the design equations as presented in the ASCE Structural Plastics Design Manual, the design equations that can be used to predict the ultimate compressive stress of the compression members were proposed.

scholarly journals Recalcitrant betas: Intraday variation in the cross‐sectional dispersion of systematic risk

2021 ◽  
Vol 12 (2) ◽  
pp. 647-682 ◽  
Author(s):  
Torben G. Andersen ◽  
Martin Thyrsgaard ◽  
Viktor Todorov
Keyword(s):  
High Frequency ◽  
Opposite Effect ◽  
Functional Limit ◽  
Cross Sectional ◽  
Macroeconomic News ◽  
Market Index ◽  
Cross Sectional Dimension ◽  
Large Panel ◽  
The Cross ◽  
Over Time

We study the temporal behavior of the cross‐sectional distribution of assets' market exposure, or betas, using a large panel of high‐frequency returns. The asymptotic setup has the sampling frequency of returns increasing to infinity, while the time span of the data remains fixed, and the cross‐sectional dimension of the panel is either fixed or increasing. We derive functional limit results for the cross‐sectional distribution of betas evolving over time. We demonstrate, for constituents of the S&P 500 market index, that the dispersion in betas is elevated at the market open and gradually declines over the trading day. This intraday pattern varies significantly over time and reacts to information shocks such as clustered earning announcements and releases of macroeconomic news. We find that earnings news increase beta dispersion while FOMC announcements have the opposite effect on market betas.

scholarly journals Strength and Stiffness Behavior of Earthquake Resistant Pedestrian LVL Timber Bridge

2021 ◽  
Vol 11 (2) ◽  
pp. 53-57
Author(s):  
Bernardinus Herbudiman ◽  
Delima Delima ◽  
Yosafat Aji Pranata
Keyword(s):  
Environmental Damage ◽  
Bridge Structure ◽  
Element Analysis ◽  
Cross Sectional ◽  
Bridge Superstructures ◽  
Cross Sectional Dimension ◽  
Earthquake Resistant ◽  
Beam Type ◽  
The Cross ◽  
Strength And Stiffness

A bridge is a structure which is used to connect two areas separate by obstacles. The environmental damage caused a number of reductions in the production of timber, and by that, the LVL timber which is a high quality processed or engineered timber is chosen. This research determined the design of the timber bridge structure for pedestrian with simple beam type and earthquake resistant. The load in this bridge is referring to the SNI 1725:2016 and SNI 2833:2008, the design of the girder and the connection is referring to SNI 7973:2013, and the deflection is referring to the LFRD for Highway Bridge Superstructures. The timber bridge is designed to have a span of 10 metres long and 3 metres wide. The modeling and designing of the wooden bridge are using an application called SAP2000 based on finite element analysis. Result obtained from this research indicated that the longitudinal dimension of the girder is 360 mm x 630 mm and the cross sectional dimension is 180 mm x 270 mm. The number of bolts and lock screws needed on the connection among the longitudinal girders are 40 pieces, between the longitudinal girders and the cross sectional girders is three pieces, and between the railing and the slab are two pieces. Based on the stiffness review, the results showed that the bridge deflection that occurred was lower than the permit deflection

scholarly journals Analisis Numerik Kuat Lentur Balok Support Beam Curve Tile Beton Semi Pracetak Dengan Variasi Panjang Bentangan

2020 ◽  
Vol 8 (2) ◽  
pp. 61-69
Author(s):  
Yoga Ornando ◽  
Ismeddiyanto ◽  
Iskandar Romey Sitompul
Keyword(s):  
Precast Concrete ◽  
Bending Moment ◽  
Maximum Load ◽  
Crack Pattern ◽  
Beam Length ◽  
Pure Bending ◽  
Element Analysis ◽  
Cross Sectional ◽  
Cross Sectional Dimension ◽  
The Cross

Semi precast slab is a combination of precast concrete which consist of the support beam and curve tile with the cast in place concrete. During the working process, support beam will support the entire load until the slab becomes solid. The study aims to identify the effect of using variations of support beam length towards deflection-load relationship, moment-curvature, crack pattern and cross-sectional dimensions caused by pure bending moments with the same maximum load. The variations of the support beam length are L = 3000 mm, L = 4000 mm, L = 5000 mm and L = 6000 mm which can affect the cross-sectional dimensions of the support beam. The method used in this study was the numerical method by using Abaqus 6.14 CAE software. Abaqus is one of the finite element analysis (FEA) programs to model and analysis the elements of the structure. The loading applied was an axial load which has increased until the support beam failed. The numerical analysis results are the increase of cross section dimension as the increasing of support beam length. The cross-sectional dimension are 100 mm x 60 mm; 110 mm x 65 mm; 110 mm x 70 mm; and 115 mm x 75 mm. The maximum load (Pmaks) was relative same while the support beam length increased are 1,52 kN; 1,53 kN; 1,53 kN and 1,55 kN. The collapse pattern on the support beam was a pure bending crack at the most significant bending moment region. The crack pattern showed the crack on the pull side of the beam in the direction of the stirrups.Semi precast slab is a combination of precast concrete which consist of the support beam and curve tile with the cast in place concrete. During the working process, support beam will support the entire load until the slab becomes solid. The study aims to identify the effect of using variations of support beam length towards deflection-load relationship, moment-curvature, crack pattern and cross-sectional dimensions caused by pure bending moments with the same maximum load. The variations of the support beam length are L = 3000 mm, L = 4000 mm, L = 5000 mm and L = 6000 mm which can affect the cross-sectional dimensions of the support beam. The method used in this study was the numerical method by using Abaqus 6.14 CAE software. Abaqus is one of the finite element analysis (FEA) programs to model and analysis the elements of the structure. The loading applied was an axial load which has increased until the support beam failed. The numerical analysis results are the increase of cross section dimension as the increasing of support beam length. The cross-sectional dimension are 100 mm x 60 mm; 110 mm x 65 mm; 110 mm x 70 mm; and 115 mm x 75 mm. The maximum load (Pmaks) was relative same while the support beam length increased are 1,52 kN; 1,53 kN; 1,53 kN and 1,55 kN. The collapse pattern on the support beam was a pure bending crack at the most significant bending moment region. The crack pattern showed the crack on the pull side of the beam in the direction of the stirrups.

A Discussion on How Internal Pressure is Treated in Offshore Pipeline Design

2004 ◽  
Author(s):  
Nelson Szilard Galgoul ◽  
Andre´ Luiz Lupinacci Massa ◽  
Cla´udia Albergaria Claro
Keyword(s):  
Internal Pressure ◽  
Axial Force ◽  
Research Work ◽  
Lateral Force ◽  
Poisson Effect ◽  
Cross Sectional ◽  
Starting Point ◽  
Global Buckling ◽  
Temperature And Pressure ◽  
Fixed End

The design of rigid submarine pipelines has been the object of extensive research work over the last few years, where the most relevant issues include upheaval and lateral buckling problems. Both of these problems systematically associate temperature and pressure loads, where the treatment of the first is obvious, while the latter have always been a matter of discussion. In 1974 Palmer and Baldry [1] presented a theoretical-experimental contribution, in which they have set a pattern that has been followed ever since. Another similar and well known paper was published by Sparks in 1983 [7], who only present a physical interpretation of this same theory. Most of the present day industry codes define an effective axial force, according to which, fixed end pipelines will be under compression due to internal pressure. The starting point of the discussion presented in [1] was that internal pressure produces a lateral force, which is numerically equal to the pressure times internal cross-sectional area times the pipeline curvature: q=p.Ai.d2y/dx2(1) This equation is demonstrated further ahead in this paper. Palmer and Baldry then based their arguments on the traditional equation of the pinned column buckling problem, studied by Euler [2]: EId4y/dx4+Pd2y/dx2=0(2) for which the well known solution is: P=π2EI/L2(3) and on the associated problem studied by Timoshenko [3], which adds a distributed lateral load q to the same problem: EId4y/dx4+Pd2y/dx2=q(4) Replacing q with the lateral pressure given above, they were able to have their own problem fall back onto the Euler solution: EId4y/dx4+Pd2y/dx2=p.Ai.d2y/dx2P-pAi=π2EI/L2(5) After correcting for the Poisson effect they were able to determine the new critical axial force caused by the pressure. Unfortunately, however, the arguments set forth in [1] have been misunderstood. The fact that both axial force and lateral force multiply curvature does not make them forces of the same nature. Being able to add them has solved a mathematical equation, but still hasn’t converted the lateral force to axial. The authors wish to prove that [1] presents no more than a tool, which can be used in the analysis of global buckling problems of pipelines subject to both temperature and pressure. It will be shown, however, that this pressure will not produce an axial force, as now-a-days prescribed conservatively in many pipeline codes, which is even used for stress checking.

scholarly journals Numerical study of bracing section variations in an eccentrically braced frame

2020 ◽  
Vol 156 ◽  
pp. 05012
Author(s):  
Sabril Haris ◽  
Nidiasari ◽  
Sonya Triaz Pramadhani Putri
Keyword(s):  
Ultimate Load ◽  
Numerical Study ◽  
Cross Sectional ◽  
Braced Frame ◽  
Eccentrically Braced Frame ◽  
Moment Resisting Frame ◽  
Cross Sectional Dimension ◽  
Moment Resisting ◽  
The Cross ◽  
Short Link

Eccentrically Braced Frame (EBF) is a better option for the earthquake-prone country due to it having a better strength, stiffness, energy dissipation and ductility than Moment Resisting Frame (MRF) structure and more so than structures made of concrete. The structure’s ductility was influenced by the cross-sectional dimension and link element of the frame. This study aims to determine the relation behavior of EBF with the varied link element and cross-sectional of bracing with the ultimate load and ductility of the structure. The analysis was done using MSC. PATRAN/NASTRAN student edition software. A total of three-link model variations, each one represents the three-link variations of EBF; short link, intermediate link, and long link. As for the cross-sectional, variation was made on the flange and web thickness of the IWF profile and web thickness of the HSS profile. The most optimum performance of the structure was determined by displacement control and static monotonic loading. The result indicates that variations in the crosssectional of bracing effects the short link EBF the most, while the intermediate and long link EBF doesn’t show a significant change in terms of ultimate load. Meanwhile, ductility is not bound by the increase of bracing thickness.

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