Question

(2) As shown in the figure, check whether the strength, global stability and local stability of the axial compression member can meet the requirements. The axial load design value N=1500KN, column height is 7m, a lateral support point is set in the x-axis direction of the mid-point of the column height, steel Q235B, F#215N/mm2, section without any weakening. (Full score is 20) N -250 X 14 у 3500 х х 7000 -250 X 8 3500 у X -250 X 14 Unit: mm N. II

Answer 1

Given Length Ly = 7000 = 3500 mm Length Ly= 7000mm Column is Pinned Pinned Connection. (K=1) find the Section properties of Ix and Ty neutral axis will be present in due to symmetry. now Ix (990x14 + (250 x14 )x1327] x2 3 8x250" -12 132.499810 ommy 250x14 the middle 250X8 12 1250x14 (0xs Emmy aby Jy = 14x 250 x 2 + 250 x83 =/36-469 x0 & Critical Load in x-direction : Per mm 2 TERX x 2x105N x 132.4998106 mm 4 (K L x)? ((x 350o)? Por=21,350.411 KN KN] Critical Load in y direction : for a TETY nxoxox 36.4898006 (klygr (1x7ooo) Per 2 1469-12 KN Stress coming on Columns Load * 150000°N (250/14)9x(20018) (166.667 N/mm Stress Stress Coming 166.667N < f ( 215 N/mm) column faile in buckling only

and Column is Sare in x-cexis Loading for given Loading as 1500KN 221,350.411 KN but Column will fail about y-aris Loading as 1500 > 14969.12 KN (so buckles about y-aris ) Check for Local stability of web: dah (250 +14414) 34.75 tw 8 de = 0.75 € 22.875 215 Mpa 0.75/2x10 Supa since (Fy Idé de bor web, web backling Clocas bucketing Soccurens Local stability of flange :- Check for 250 da bf - 8-929 att 2 (14) TE 17.08 da= 0.56 0. 56/2005 215 since dedi] Flange is safe against Local buckling
thank you.