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NOW DETERMINE k2 FROM LUTTRELL'S FORMULA <br /> Et 29,000,000'0.016S <br /> <br /> [2(l+V)g/p+k2/(144tt*0.0165)^2] [2'(1+0.3)'1.2+k2/(144'.0165)^2] <br /> <br />value = 2~542.78 <br /> <br />THE ROOF SLOPE LENGTH FROM CENTER OF THE HAVE GIRT TO CENTER OF RIDGE <br />PURLIN, L= 92.77 INCHES <br /> 29t000~000,*0.0165 <br /> C = .............................. = 439.65 <br /> [2*(l+.3)*lo2+k2/(L*.0165)^2] <br /> <br />Ch=C * (COS A)^2 * 2= 827.58 <br /> <br />DETERMINE THE RELATIVE STIFFNESS OF FRAME TO ROOF <br /> k/Ch = 0.5754 <br /> <br />DETERMINE mD AND mS REDUCTION FACTORS FROM TABLES i AND 2 <br />(GEEREMEDHIN PGs. 1366-1367) BASED UPON THIS STRUCTURE HAVING <br />5 FRAMES INCLUDING THE ENDWALLS. <br /> <br />mD= 0.5376 mS= 0.5376 <br /> <br />STEP #4: CALCULATE THE RESIATANCE FORCE TO SIDESWAY AND SHEAR FORCE <br />IN THE ROOF CLADDING. <br />RESISTANCE FORCE TO SIDEWAY = mD * ROLLER REACTION (from ~tep#1) <br /> 0.5376 * 563.88 = 303.14 <br />ROOF CLADDING SHEAR FORCE = mS * ROLLER REACTION <br /> 0.53?6 * 563.88 = 303.14 <br /> <br />STEP#5 : DISTRIBUTE THE RESISTANCE FORCE TO SIDESWAY EQUALLY AT THE <br />TOP CHORD NODES OPPOSITE THE WIND LOADING ON THE WALLS. <br /> NUMBERS OF NODES= 5 <br />RESIST~NCE FORCE/NO. of NODES= 60.63 lbs./EACH NODE <br /> <br />THE MAXIMUM COMBINED STRESSES INTERACTION VALUE= <br /> 0.58 <1.0 <br />THEREFORE USE 6x6 HFIR #2 is O.K. <br /> <br />STEP #6= CHECK SHEAR IN ROOFING NEAR ENDWALLS. <br />ROOF CLADDING SHEAR FORCE (STEP #4)/BUILDING WIDTH MUST BE LESS OR <br />EQUAL TO THE ADJUSTED SHEAR (V) FROM STEP #3 ADJUSTED FOR LOAD <br />DURATION (1.3333) <br /> 303.14 / 7.50 = 40.42 plf. <br /> 40.42 < (87.92*1.3333)= 117.22 <br /> 40.42 <br /> <br />CHECK SHEAR TRANSFERRED TO ENDWALL DIAPHGRAM. <br />ROOF CLADDING SHEAR FORCE (STEP #4)/EUILDING WIDTH LESS DOOR <br />OPENINGS MUST BE LESS OR EQUAL TO USEABLE SHEAR FROM STEP #3 <br />ADJUSTED FOR THE ON CENTER SPACING OF THE ENDWALL GIRTS ADJUSTED FOR <br />LOAD DURATION (1.3333) <br />18'END -0'DOOR(~)= 7.50 fT. USEABLE <br /> 303.14 / 7.50 = 40.42 <br /> <br /> <br />