AISC 360-10, KEPIC SGE

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 -