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Structural <br /> Engineering & Design Inc. <br /> 1815 Wright Ave La Verne, CA 91750 Tel: 909.596.1351 Fax: 909.596.7186 <br /> By: Bob S Project: Terra Power Project#:24-0325-11 <br /> Column(Longitudinal Loads) Configuration:TYPE 1 SELECTIVE RACK <br /> Section Properties <br /> Section; SPCRK FH:20/3x3x14ga - - - - -3.000 In.. <br /> Aeff= 0.643 in^2 Iy= 0.749 in^4 Kx= 1.7 <br /> Ix= 1.130 inA4 Sy= 0.493 in^3 Lx= 60.5 in . <br /> Sx= 0.753 inA3 ry= 1.080 in Ky= 1.0 y_._.r.._..yi 3.000 In <br /> rx= 1,326 in Fy= 55 ksi Ly= 36.0 in j0.075 in <br /> S2f= 1.67 Cmx=.0.85 Cb= 1.0 _ • _1 <br /> E= 29,500 ks1 <br /> ,r1I .0.75 in <br /> Loads Considers loads at level 1 <br /> COLUMN DL= 112 lb Critical load cases are;RMI Sec 21 <br /> COLUMN PL= 4,200 lb Load Case 5;;(1+0.105*Sds)D+0.75*(1.4+0.14Sds)*B*P+0.75*(0,7*rho*E)<=1.0,ASD Method <br /> Mcol= 14,302 in-lb axial load coeff: 0.8136156*P seismic momentcoeff; 0,5625*Mcol <br /> Sds= 1.0696 Load Case 6; (1+0.14*Sds)D+(0.85+0.14Sds)*8*P+(0.7*rho*E)<=1.0,ASD Method <br /> 1+0.105*Sds= 1.1123 axial load coeff: 0.69982 seismic momentcoeff; 0,7*Mcol <br /> 1.4+0.14Sds= 1.5497 By analysis,Load case 6 governs utilizing loads as such <br /> 1+0.14Sds= 1.1497 <br /> 0.85+0.14*Sds= 0.9997 Axial Load=Pax= 1.149744*112lb+0.999744*0.7*4200lb Moment=Mx= 0.7*rho*Mcol <br /> B= 0.7000 = 3,068 lb = 0.7*14302 in-lb <br /> rho= 1.0000 = 10,01i in-lb <br /> Axial Analysis <br /> KxLx/rx= 1.7*60.5"/1.326" KyLy/ry.= 1*.36"/1.08" Fe > Fy/2 <br /> = 77.6 = 33.3 Fn= Fy(1-Fy/4Fe) <br /> = 55•ksi*[1-55 ksi/(4*48.4 ksi)] <br /> Fe= nA2E/(KL/r)max^2 Fy/2= 27.5 ksi = 39.4 ks1 <br /> = 48.4ksi Pa= Pn/S2c <br /> Pn= Aeff*Fn Sic= 1.92 = 25317 lb/1.92 <br /> = 25,317lb = 13,186 lb <br /> P/Pa= 0.23 > 0.15 <br /> Bending Analysis <br /> Check: Pax/Pa+(Cmx*Mx)/(Max*px)S 1.0 <br /> P/Pao+Mx/Max 5 1.0 <br /> Pno= Ae*Fy Pao= Pno/S2c Myield=My= Sx*Fy <br /> = 0.643 inA2*55000 psi = 353651b/1.92 = 0.753 In^3*55000 psi <br /> = 35,365 lb = 18,419 lb = 41,415 in-lb <br /> Max= My/Sif Pcr= n^2EI/(KL)max^2 <br /> = 41415 in-lb/1.67 = n^2*29500 ksi/(1.7*60.5 in)^2 <br /> = 24,799 in-lb = 31,102 lb <br /> px= {1/[1-(52c*P/Pcr)]}^-1 <br /> = {1/[1-(1.92*3068lb/311021b)]}^-1 <br /> = 0.81 <br /> Combined Stresses <br /> (3068 lb/13186 lb)+(0.85*10011 in-lb)/(24799 in-Ib*0.81)= 0.66 < 1,0,OK (EQ C5-1) <br /> (3068 lb/18419 lb) +(10011 in-lb/24799 In-lb) = 0.57 < 1.0,OK (EQ C5-2) <br /> **For comparison,total column stress computed for load case 5 is; 60.0% 7g loads 3541,764016lb Axial and M= 7508In-lb <br /> type 2 select-06-Terra.xls Page 'j of t y 3/26/2024 <br />