AISC 360-10, KEPIC SGE

2011년도 대한전기협회 KEPIC-Week 발표자료 S1-22011 KEPIC-Week, Jeju (AISC 360-10, KEPIC SGE) : ( ) )Structures Lab. Department of Civil Engineering, Hongik University2011 KEPIC-Week, Jeju Structures Lab. Department of Civil Engineering, Hongik University- 19 -

2011 KEPIC-Week, Jeju Structures Lab. Department of Civil Engineering, Hongik University2011 KEPIC-Week, Jeju Structures Lab. Department of Civil Engineering, Hongik University- 21 -

(Failure Modes)2011 KEPIC-Week, Jeju Overall LocalStructures Lab. Department of Civil Engineering, Hongik University2011 KEPIC-Week, Jeju (1) Flexural bucklingdydzP yEI2 02F(2) Torsional bucklingd EIdd 4 2P4 202zdzcr2 EKL / r21ECwFez GJ2 IP ( KL)(3) Flexural-torsional bucklingxzd I d d v d uECwGJ P Px Pyd A d d d4 2 2 2 0 4 2 02 002z z z zF ex F ez4FexFezHFe 1 112H F 2ex F ez Ix IyHI0Structures Lab. Department of Civil Engineering, Hongik University- 22 -

2011 KEPIC-Week, Jeju k b/t 0.425 0.43 E / Fy 1.277 4.000 6.9700.75 E / Fy1.33 E / Fy1.76 E / FyStructures Lab. Department of Civil Engineering, Hongik University 2011 KEPIC-Week, JejuPlate Buckling AnalysisaAribtrary SupportN xSimple Supp pporttbSimple Supp pportN xAribtrary SupportBuckling StrengthFcr k2 E2b12(1 ) t 2Structures Lab. Department of Civil Engineering, Hongik University- 23 -

2011 KEPIC-Week, Jeju F crDue to strain hardeningFcr [ 1.5]2E( KL / r)e1 F2 2eyInelastic Elastic 10F 1.0 F yF cr= 0.877 .2 F y e0.39F yF cr= 0.658 2e . F y1.5 KEPIC-SGE (AISC/LRFD) F e=yStructures Lab. Department of Civil Engineering, Hongik UniversityF eFcr 12.3%0.877 F ey [ 1 1.5] F F r 0.3F y cr0.658 e2eFye2011 KEPIC-Week, Jeju Structures Lab. Department of Civil Engineering, Hongik University- 24 -

2011 KEPIC-Week, Jeju Structures Lab. Department of Civil Engineering, Hongik University2011 KEPIC-Week, Jeju Batten Angle shape Channel shape BattenStructures Lab. Department of Civil Engineering, Hongik University- 25 -

2011 KEPIC-Week, Jeju 0.75 E/ Fy Structures Lab. Department of Civil Engineering, Hongik University2011 KEPIC-Week, Jeju KL KL a r m r o ri22KL : rm KL : r o 2 2 KL KL a2 0.82 (12 r m r o ) rib h2riba/r i : a/r ib : a : r i : r ib : Structures Lab. Department of Civil Engineering, Hongik University- 26 -

2011 KEPIC-Week, Jeju a40,r KL KL a 40,i r m r r o i KL KLKai r m r o ri22K i : 0.5 for angles back to back: 0.75 for channels back to back: 0.86 for all other casesStructures Lab. Department of Civil Engineering, Hongik University2011 KEPIC-Week, Jeju G EI LEI L columnbeamStructures Lab. Department of Civil Engineering, Hongik University- 27 -

2e2011 KEPIC-Week, JejuyDouble-Angle l Shaped Sectionx xyP u , KxLx,KyLy,KzLz,FySelect a SectionDistance between Connectors KxLxKyLya rz Max. , rxry KLy KLy rzm rzoYesfor Welds or Fully Tightened Bolts1722 KLy KLy K i a a rz m ry r o i 40Nor for Snug-Tight Boltsz2 2 KL 18y KLy a rzm ryo ri2221 E2 E3 EC w 1F ex , F ey , F ez GJ222 2K xLx K yLy KzLz Ar 0 r x r y m4F ey F ez 4 F ey F ez H F e11 1 2 2 H Fey F ez F e = Minimum [F ey , F e1 ] e5F yF eb E 0.45t f F yNotbE 0.91f F yNoYesQ 1 . 0QYes11s 1.340 0. 76b Fyt E0.53 E b Fy t 10 Qs2QQs8 0 . 877eQ 1.5No F cr F y 2e YesNoF9 cr0 .658Q Q Fy22Stop Yes Pu Pn Pn = 0.85 Fcr AgStructures Lab. Department of Civil Engineering, Hongik University2011 KEPIC-Week, JejuMathcad Ver. 14Unitkips 1000lbff ksi 1000psipPa 1.45010 7 ksi MPa 10 6 PaInput DataResistance Factor: c 0.85HomeFactored Load P u 200kipsEffective Length Factor K x 1 K y 1 K z 1Length L x 8ft L y 8ft L z 8ftYield Stress F y 36ksiModulus of Elasticity E 29000ksiPoisson's Ratio 0.3Shear Modulus of ElasticityEG 2( 1 )Structures Lab. Department of Civil Engineering, Hongik University- 28 -

2011 KEPIC-Week, JejuSectional properties of single angleSectional properties tabulated in the AISC Manual (AISC Third Edition)Area A g 5.80in 2 Long leg b 1 8inShort leg b 2 4inThickness1t 2 inAxis X-X Moment of inertia I x 6.75in 4 Radius of gyration r x 1.08inCentroid y 0 0.854inAxis Y-Y Moment of inertia I y 38.6in 4 HomeRadius of gyration r y 2.58inCentroid x 0 2.84inAxis Z-Z Radius of gyration r z 0.863inTorsional Properties Torsional constant J 0.501in 4 Warping constant C w 1.8in 6Structures Lab. Department of Civil Engineering, Hongik University2011 KEPIC-Week, JejuSectional Properties of double angleInput the type of double angle section ( SLBB, LLBB ), connector type ( weld, bolt, snugtighted bolt) and number of connectorsType "SLBB"3Batten 8 Connector_Type "Bolt"Number_Connector 3Where, SLBB and LLBB are the short leg back to back and long leg back toback, respectively.Using single angle sectional properties, double angle sectional properties can becaculated as followsGross areaHomeA 2g 2A gA 2g 11.6in 2Radius of gyrationr 2x r x if Type "SLBB"r y if Type "LLBB"r 2y 3.97in r 2z r zr 2x 1.08in r 2y 3.97in r 2z 0.863inStructures Lab. Department of Civil Engineering, Hongik University- 29 -

2011 KEPIC-Week, JejuFlexural-torsional properties tabulated in the AISC Manual al (AISC Third Edition)r 0 4.16in H 0.979C 2w C w 2J 2 J2 C 2w 3.6in 6 J 2 1.002in 4Substituting the member length and number of connectors, distance betweenconnectors measured along the member length can be caculated as followsK y L ya a 24inNumber_Connector 1Modfied Slenderness RatioDistance between centroids of individual components is defined as followsaccording to type of double angle sectionHomeh 2y 0 Batten if Type "SLBB"h 2.083in2x 0 Batten if Type "LLBB"r ib r yr ib 2.58inWhere, r ib is radius of gyration of individual component relating to its centroidalaxis parallel to the member axis of buckling (for double angle members it is r y )Seperation ratio is defined as followsh 0.4042r ibThe modified slenderness ratio is also dependent on the slip-resistance of theconnections. AISC LRFD Chapter E4.1 provides m K y L yif a 40inr 2yotherwise2 2 K y L y K i a r 2y r if Connector_Type 2y"Bolt" "Weld"2 K y L y 2a r r if Connector_Type 2y z"Snug Bolt"Structures Lab. Department of Civil Engineering, Hongik University m = 24.37 (AISC 360-05) m 24.181 (AISC 360-10)2011 KEPIC-Week, JejuBuckling StressThe elastic buckling stresses about the x, y, and z axes are defined as follows2 2 E 2 E EC 2wF ex F2 ey F2 ez K x L x m K z L z r 2x 2 GJ 2F ex 36.225ksi F ey 489.482ksi F ez 56.23ksi12A 2g r 0Using AISC LRFD-Formula A-E3-6, the flexural-torsional buckling stress can becalculated cu ated as follows o where e y is the axis of symmetryyF ey F ez 4F ey F ez HF e1 1 1 2H F ey F ez 2F e1 56.078ksiThe buckling stress is defined as the lowest of the elastic and flexural-torsionalbuckling stress obtained previoulsy. Thus,F 36 225k iF e min F ex F ey F e1F e 36.225ksiSlenderness ParameterUsing AISC LRFD-Formula F (A-E3-4), the slenderness parameter e is defined d asfollowsHomeF y e 0.997FeeStructures Lab. Department of Civil Engineering, Hongik University- 30 -

2011 KEPIC-Week, JejuRd Reduction FactorFlange widthb b 1 if Type "SLBB"b 8inb 2 if Type "LLBB"From AISC LRFD Appendix B-5.3a (a), reduction factor Q can be obtained asfollowsQ b1 if 0.45EQ 0.912t F yotherwise1.340 0.76b t F yEbif 0.91tEF y0.53E2otherwisebF y t HomeCritical Buckling StressFrom AISC LRFD-Appendix B-5 3d, the critical stress F cr is determined asfollowsF cr Q 0.658 Q 2 e Fy if e Q 1.5F cr 22.46ksi0.877F y otherwise2 eDesign StrengthCheckP n F cr A 2gP d c F cr A 2gP d 221.46kips P u 200kipsCheck "This section is O.K." if P u P d"N.G. Select a section again." otherwiseHomeCheck "This section is O.K."Structures Lab. Department of Civil Engineering, Hongik University2011 KEPIC-Week, Jeju Structures Lab. Department of Civil Engineering, Hongik University- 31 -