EFFECT OF BATTEN PLATES ON STEEL I-BEAMS FLEXURAL
International Journal of Scientific & Engineering Research, Volume 9, Issue 12, December-2018ISSN 2229-5518651EFFECT OF BATTEN PLATES ON STEEL IBEAMS FLEXURAL STRENGTHAhmed Hassan, Sherif M. Ibrahim, Abdelrahim K. DessoukiABSTRACT—This paper investigates the effect of batten plates on the flexural capacity of laterally unsupported simply supported steel I-beams. Lateraltorsional buckling (LTB) failure mode always controls the flexural capacity of such beams. A Nonlinear finite element model for the doubly symmetric Ibeams stiffened with batten plates is presented. The proposed model accounts for initial geometric imperfections and material non-linearity. Firstly, thefinite element model is applied on unstiffened steel I-beams to obtain a reference value of the flexural capacity. Subsequently, a parametric study isperformed to illustrate the increase in flexural strength of the same beams that are stiffened with batten plates of various configurations. The parametersin the research includes the location of batten plates along the beam span, the number and the dimensions of the batten plates. Moreover, the study isperformed on both double sided and single sided for batten plates. Design charts are presented to predict the increase in flexural capacity of steel I-beamswith various batten plates configurations. A simplified design procedure is proposed to predict the flexural strength of beams with batten plates. Theresearch results indicate that batten plates are very efficient in increasing LTB capacity of steel I-beams when it is challenging to add lateral bracing.Index Terms—Lateral torsional buckling, Batten plates, T-stiffeners, simply supported beams, Finite element analysis.—————————— ——————————1INTRODUCTIONSteel beams are usually used in all types of steel structureswith various applications. They are used as floor beams formultistory buildings or as main girders for portal frames.Steel beams are also used for some special applications suchas monorail beams or crane track girders. Moreover, they areused in bridge main supporting elements. The load-carryingcapacity of steel I-beams is controlled by the unsupportedlength of compression flange of the steel cross section. If alaterally unsupported beam is loaded vertically, it deflectsabout its main axis while the compression part of the beamtends to deflect laterally about the weak axis and twist aboutthe longitudinal axis of the beam. This behavior is calledlateral torsional buckling (LTB). Lateral bracing for thecompression flange is used to increase the flexural capacityof the steel elements subjected to pure flexural stresses orflexural stresses accompanied with axial stresses. Lateralbracing reduce the unsupported buckling length for thecompression flange by preventing its lateral movement atbraced points. Stiffeners are often used to increase web shearcapacity for plate girders with big depth and to support thegirder web against local buckling. For hot rolled sections,stiffeners are used at the connections locations to strengthenthe web capacity and prevent local stresses. Also stiffenersare used at the coped region position in the beams tostrengthen the web.The main aim of this research is to investigate the behaviorof laterally unsupported simply supported steel I-beamsstiffened with single or double-sided batten plates. Aparametric study is conducted using non-linear finiteelement model to evaluate the effect of different batten plateconfigurations on the flexural strength of laterallyunsupported simply supported steel ��——— Ahmed Hassan is an assistant lecturer, structural engineering department,Ain Shams University, Egypt. E-mail: Ahmed Hassan91@eng.asu.edu.eg Sherif M. Ibrahim is an Associate Professor, structural engineeringdepartment, Ain Shams University, Egypt, PH-201065507338. E-mail:sherif.ibraim@eng.asu.edu.eg Abdelrahim K. Dessouki is a Professor, structural engineeringdepartment, Ain Shams University, Egypt. E-mail:abdelrahim dessouki@eng.asu.edu.eg2LITERATURE REVIEWTimoshenko and Gere [1] presented a closed form solutionfor the critical bending moment of a simply supported beamsubjected to uniform moment across the beam length.The critical moment equation was modified using a factorCb to take into account different loading conditions. Thefinal elastic critical lateral torsional buckling moment usedby most design specifications such as AISC [2] and SSRCGuide [3] is represented by:M cr.e C b 2 .E.I y .G.J L b 2 4 .E.I y .E.C w L b 4(1)Where Lb is the unsupported length of the beam, E isYoung’s modulus, Iy is the minor moment of inertia of thecross section, G is the shear modulus, J is the shear constantand Cw is the warping constant. The actual flexural capacityof laterally unsupported I-beam may be lower than valueobtained from (1) if inelastic LTB or full plastification of thecross section are the dominate failure modes. The upper limitfor the member flexural capacity is the plastic momentcapacity of the beam (for beam with compact cross sections).As the unsupported length decreases, the failure mode of thebeam is considered inelastic lateral torsional buckling.Inelastic lateral torsional buckling is achieved when someparts of the section reach the yield stress with the beamexperiencing lateral movements with twisting. As theunsupported length of the beam exceeds a certain value thefailure mode for the steel beam is considered pure elasticlateral torsional buckling (LTB).IJSER 2018http://www.ijser.org
International Journal of Scientific & Engineering Research, Volume 9, Issue 12, December-2018ISSN 2229-5518Szewczak et al [4] investigated the behavior of beamsstiffened with different stiffener configurations undertorsional loading. They suggested that transverse stiffeners(i.e. web stiffeners) are not effective in reducing warpingnormal stresses and displacements. However, longitudinalstiffeners (i.e. batten plates) are moderately effective inresisting torsional stresses.Takabatake [5] attempted to develop a mathematicalsolution for the LTB capacity of steel doubly symmetric Ibeams stiffened with stiffeners or batten plates. Hismathematical solution was derived by energy method basedon the following assumptions :1) the beam is doublysymmetric, 2) the initial imperfections and residual stressesare neglected, and 3) only elastic lateral buckling isconsidered. He suggested that the increase in beam flexuralcapacity stiffened with stiffeners and/or batten plates is dueto local increase of both torsional constant and weak axisinertia at the stiffeners locations. He suggested that stiffenersor batten plates had no effect on the beam warpingresistance. He attributed this to the fact that stiffeners orbatten plates do not exist continuously along the beamlength. According to that, the warping constant for theunstiffened-beam was used. Takabatake [5] compared histheoretical results of the stiffened beam to unstiffened beam.The maximum increase noticed was 260% over theunstiffened beam (for the beam stiffened with batten platelocated near the support location).Takabatake et.al [6] followed the aforementioned theoreticalresearch with experimental work for beam stiffened withstiffeners or batten plates. Their results showed that thebeam stiffened with batten plates or stiffeners has a biggercritical moment compared to the original unstiffened beam.The increase in beam elastic flexural capacity is bigger if thestiffener is located near the support. They also found that thepresence of batten plates has a better effect on criticalmoment than vertical web stiffeners. However, theirexperimental results did not agree with their previoustheoretical work.Hassanien [7] investigated the effect of vertical webstiffeners on the LTB capacity for cantilever steel I-beam. Hesuggested that the web stiffeners are connecting thecompression flange with the tension flange which reducesthe lateral movement of the compression flange. Heindicated that the presence of 6 vertical stiffeners results inaverage of 25% increase in cantilever beam elastic criticalLTB moment.Yang and Lui [8] investigated the effect of inclined stiffenerson the LTB capacity of doubly symmetric steel I-beam. Theyinvestigated the effect of inclined stiffeners on the flexuralcapacity of doubly symmetric steel I-beams. Double sidedinclined stiffeners with inclination angle θ were welded tothe beam flanges. The study was conducted using nonlinearfinite element method. The material nonlinearity and initialgeometric imperfections were considered in their study.Various parameters were considered regarding the inclinedstiffeners configuration. Their study showed that theinclined stiffeners have a significant effect of the LTB652capacity for steel I-beams. The best location for inclinedstiffeners is near the beam supports.Sorensen and Rasmussen [9] investigated the effect ofvertical stiffeners and vertical stiffeners combined withshort longitudinal stiffeners (i.e. Box stiffener) on thewarping resistance of simply supported beams. Thestiffeners were installed at mid-span of the beam. Anexperimental study was conducted to investigate thestiffener effect on the capacity of simply supported beams.A point load was applied at mid-span. The used section wasIPE 80 with length of 5m.3NUMERICAL MODELING3.1 Construction of Finite Element ModelA numerical finite element analysis is conducted to studythe effect of batten plates on the LTB capacity of laterallyunsupported simply supported steel I-beams. The finiteelement method as described by Zienkiewicz and Taylor[10] has been proven to be very efficient to simulate suchcases. The program used in modeling is ANSYSMECHANICAL APDL v14.5 [11]. The model includes allbeam components which are flanges, web, end plates andbatten plates. These beam components are modeled usingfour-node thin shell element (SHELL181) with six degrees offreedom at each node. This element is formulated to besuitable for thin to moderately-thick shell structures for bothlinear and nonlinear analyses. An end plate with thicknessof 16 mm is used at the beam ends to avoid any stressconcentration at the steel beam ends (i.e supports location).The beam supports are represented to simulate true hingedsupport condition that is free to warp and prevented fromtorsion. The lower node of the web at the conjunction withthe lower flange was prevented from vertical movement andlateral movement (Ux and Uy). The Upper node of the webat the conjunction with the upper flange was prevented fromlateral movement only (Ux). Only one of the lower nodes ofthe beams was prevented from longitudinal movement (Uz)to achieve beam stability condition. The uniform momentloading condition is modeled using a couple of twoconcentrated loads with opposite directions. The finiteelement model with the aforementioned criteria is shown inFig. 1.IJSERFig. 1. Sample for modeling of the beam stiffened with double sidedbatten plates under uniform bending.IJSER 2018http://www.ijser.org
International Journal of Scientific & Engineering Research, Volume 9, Issue 12, December-2018ISSN 2229-5518value for simply supported beam under uniform bending.The studied beam was W12x58 with different lengths tocover the full behavior of the studied beam. They studied sixdifferent spans for the studied beam varying from 120 to 420inches in 60 inches increment and obtained the criticalmoments by linear and nonlinear analyses. The materialproperties for this study were (Yield stress Fy 345 MPa,Young’s modulus E 210 GPa, Tangent modulus Et 5%Eand Poisson ratio υ 0.3 ).A set of finite element models are constructed to verify theproposed model with the finite element results that weregiven by Yang and Lui [8]. The verification results for the sixcases showed a good agreement with the same results thatwere presented by Yang and Lui [8]. The detailedverification results are presented in Fig. 3 and 4 for bothlinear and nonlinear analyses.Elastic critical moment2200Mcr.e (kN.m)The initial geometric imperfections are considered in themodeling procedure. According to ASTM A6/A6M-11 [12],the maximum allowable value for lateral deformations(sweep) for I-shapes beams is defined by L/960. In thisstudy, a value of L/1000 is used as initial geometricimperfections. It is to be mentioned that L/1000 is themaximum out of straightness value for compressionmembers defined in the code of standard practice AISC [13].This initial imperfection is implemented in the nonlinearfinite element model by conducting a linear bucklinganalysis on the studied beam to obtain the critical LTBfailure mode shape. This critical buckled shape obtainedfrom linear buckling analysis is normalized by setting themaximum lateral deformation at mid-span to a value ofL/1000. Using “update geometry” command in ANSYSprogram, the normalized buckled shape is considered to bethe initial shape of the studied steel beam in the nonlinearfinal finite element model. For all the specimens, a nonlinearmaterial properties are considered. The stress strain curve isassumed to be a bilinear curve. The material used is steelS235 with elastic modulus of elasticity (E 210 GPa), yieldstrength (Fy 235 MPa) and Poisson’s ratio (υ 0.3). Thetangent modulus (Et) is used with an approximate value of10% of the used steel elastic modulus (Et 0.1E). Fig. 2represents the used material properties for all 2000L (mm)Yang & Lui 2012Current FEMFig. 3. Verification of elastic analysisFig. 2. Idealized bilinear stress strain curveFinal critical moment3.2 Model VerificationThe proposed finite element model is verified with previousresearch works. The verification process is an important stepto prove the capabilities of the proposed model to simulatethe studied cases of steel beams stiffened with batten plates.The model verification is conducted with the finite elementwork done by Yang and Lui [8] and with the experimentaland finite element work done by B. Yang [14]. Yang and Lui[8] checked their finite element models with design codeequations for elastic and final (nonlinear) critical momentIJSER 2018http://www.ijser.org500450Mcr.f (kN.m)The used size for the elements is approximately 50mm inboth directions which provided a reliable result withverification cases that will be described in the followingsection. The model is meshed for beam without anystiffening batten plates. Batten plates are added to the modelafter meshing the beam and then meshed. Nodal constraints(i.e. coincident nodes) are used to join the batten plate to thebeam model.400350300250200200040006000800010000L (mm)Yang & Lui 2012Current FEMFig. 4. Verification of elastic analysis12000
International Journal of Scientific & Engineering Research, Volume 9, Issue 12, December-2018ISSN 2229-5518B. Yang [14] investigated the lateral torsional bucklingbehavior of structural steel beams under concentrated load.He investigated this behavior using both experimental workand finite element analysis. The material properties wereobtained from a tensile test and could be summarized as(Yield stress Fy 410 MPa, Ultimate strength Fu 570 MPa,Young’s modulus E 211 GPa and Poisson ratio υ 0.3). Forfinite element modeling, a bilinear stress strain curve wasused with tangent modulus Et 0.1E. The initialimperfections were taken as span/1000 for finite elementmodeling. Comparison between the B. Yang [14] results andthe current finite element model is shown in Table (1). Asevident in Table (1), the verification results for the usedspecimens show good agreement for specimens DTS 2 andDTS 3 for both numerical and experimental work. However,for specimen DTS 1, the experimental results were not close tothe finite element results of original work and the currentproposed finite element model used in the verification study.TABLE 1DETAILED VERIFICATION RESULTS WITH B. YANG [14] WORKSpecimenB.YangIDresults [14]Mcr-f is the critical moment obtained from the nonlinear finiteelement model for the beam stiffened with batten plates andMcr0 is the critical moment for the control unstiffened beamobtained also from nonlinear analysis. Different parametersfor the batten plate configuration are considered. Fig. 5represents the layout for beam stiffened with double sidedbatten plates. The batten plate centerline location (Zbp) isvaried from 0.1L to 0.5L with increment of 0.1L. The battenplate number is investigated with increase of 4 batten platesfor each step with increment of 0.1L. The width of the plate(Wp) is considered equal to L/50, L/40, L/30, L/20 or L/10.The thickness of the batten plate is investigated for platethickness from 8mm to 16mm with increment of 2mm.CurrentIJSERfiniteelementFig. 5. Beam stiffened with double sided batten plates.M FEM M FEMM exp M nummodelExp.Num.MexpMnumMFEMDTS 152.647.345.50.870.96DTS 2179166.5167.70.941.01DTS 3268277.2278.31.041.00Units for moments are kN.m4654PARAMETRIC STUDY AND DISCUSSIONA set of steel beams with various spans is studied todetermine the effect of double and single-sided batten plateson the LTB capacity. The steel cross sections used for thisstudy are standard hot rolled sections (IPE 500 and HEB260). The used steel cross section is classified as compactsections with respect to local buckling conditions. Thestudied spans are 6, 10, 12 and 16 meters to cover both elasticand inelastic LTB failure modes.The flexural capacity is highly dependent on the crosssection factor of L/rts. Therefore, all results are presentedwith respect to this factor. Where L is the beam length andalso represents the unsupported length for the simplysupported loading condition and rts is approximately theradius of gyration of the compression part of the crosssection (compression flange and 1/6 of the web) or it can bycalculated exactly as provided by AISC [2].The increase in flexural capacity due to the presence of thebatten plate is represented by the ratio (Mcr-f / Mcr0). Where4.1 Effect of Batten Plate Location (Zbp)The effect of double and single sided batten plates located atdistance Zbp from both beam ends is investigated in thissection. Every specimen has four welded batten platesexcept at distance 0.5L where only two batten plates arelocated at beam mid-span. All beams are investigated underthe effect of uniform moment. The double sided batten platelocation (Zbp) varies from 0.1L to 0.5L from both beam ends.The batten plates have the dimension of Wp L/30 and tp 10mm. Where Wp and tp are the width and thickness of thebatten plate respectively.The final failure mode obtained from nonlinear finiteelement analysis for all specimens stiffened with battenplates is lateral torsional buckling accompanied with smallvertical displacements. A sample for the LTB failure mode isshown in Fig. 6. The results for the effect of the location ofdouble sided batten plates is presented in Fig. 7 and 8. Fromthe results, the effect of batten plates is more pronounced forthe case of batten plates are located near the beam supports.For the batten plates located at mid-span, minimal increasein the beam flexural strength is noticed. The batten plates aremore effective for the beams with long spans where elasticlateral torsional buckling is dominant. The maximumincrease in flexural strength is about 22% for the case ofdouble sided batten plates with dimensions of Wp L/30and tp 10 mm located at location 0.1L from both beam ends.These results show good agreement with the previousresearches that was introduced before in the literaturereview which suggested that the best location for anystiffening plates is near the supports. For IPE 500 specimenswith (L/rts 227, 303), it is noticed that both specimens havealmost the same increase in flexural strength due to presenceof stiffening batten plates. Although the yield moment forthe HEB 260 is lower than IPE 500, HEB 260 has a betterIJSER 2018http://www.ijser.org
International Journal of Scientific & Engineering Research, Volume 9, Issue 12, December-2018
lateral torsional buckling (LTB). Lateral bracing for the compression flange is used to increase the flexural capacity of the steel elements subjected to pure flexural stresses or flexural stresses accompanied with axial stresses. Lateral bracing reduce
Weight per 1,000: 5.4 tonnes Minimum Batten Size: 47mm x 35mm Batten required: 2.90 lin/m per m2 – 3.13 lin/m per m2 Positioning of irst batten: 345mm (From outside of fascia to top of batten) Tile Nails 45mm x 3.35mm Tile Clips Tile and Ver
Farm Plates Transporter Plates Dealer Plates Repair Plates Forestry Plates Antique Plates Emergency-Disaster Plates The “Host Jurisdiction” determines if plates are reciprocal. APPORTIONABLE VEHICLE Except that a truck or truck tractor, or the power unit in a combination of vehicles having a gross vehicle
Dwyer plates are available in 4, 6, 8, and 10mm steps. Note Cotton plates are available upon special request. Osteotomy Plates T8 T10 T10 Base Wedge Plates Evans Plates Dwyer Plates The BioPro Foot Plating System offers three different types of Medial Column Plates. Medial 3 Column plates for the fusion of the Talus .
Batten Disease is the common name for a group of illnesses whose medical term/name is Neuronal Ceroid Lipofuscinosis (NCL). When the NCLs are discussed they are often referred to as forms of Batten Disease. In fact, they all have the same basic cause, same progression and same outcome. However, they are differentiated by age of onset, rapidity
1 warp beam 28 9/16" 1 thread beam 31" 4 side post iron fittings 1 take-up motion handle 1 right hand side support with ratchet pawl 10½" 3 treadle blocks 2 Wood pegs ½" x 1¾" 2 batten swords 27¼" 6 treadles 20" 1 brake treadle 20" 1 treadle rod 5/16" x 30" Page 5 1 batten handtree 29" 1 batten sley 27¾" 1 breast beam 29½"
Agnus Dei (Adagio for Strings) Barber B62 SATB 3 When from my love Bartlett B36 SATB 22 O Lord look down from Heaven Batishill B48 SATB 22 Deliver us O Lord our God / O Praise the Lord Batten B45 SATB 25 Hear my Prayer Batten B46 SSATB 24 O sing joyfully (Ptb 83) Batten 1 SATB Lord, Thou hast told us (Anthems for Choirs)
It cuts and installs with carbide woodworking tools and meets or exceeds most code requirements. For additional information, visit the resources page on TruExterior.com. MATERIALS & TOOLS Materials TruExterior Boards: typically 11-1/4" wide TruExterior Batten: typically 2-1/2" wide . There are two methods of seaming board-and-batten siding on .
plates. The products are natural, compostable and biodegradable yet look stylish. The demand is high within the country too. Areca leaf plates are good replacement of thermocol plates, paper plates and plastic plates as they are eco-friendly. They are made in India and exported all over th
