Laserfiche WebLink
CR LAURENCE Z-SERIES GLASS CLAMPS (03/27/2014) Page 15 of 19 <br /> 1/4"FULLY TEMPERED GLASS <br /> Weight=2.89 psf <br /> tave=0.223" <br /> For 1/4" glass S =2*(0.223)2=0.0995 in3/ft <br /> For live loads: <br /> Mai= 6,000psi*0.0995 in3/ft=597#"/ft=49.75'# <br /> For wind load on infill glass apply 33% stress increase for SF= 3.0 <br /> Maw= 1.333*6,000psi*0.0995 in3/ft= 796#"/ft=66.33'# <br /> Moment for 36" wide lite (infill for 42"rail height) 25 psf or 50 lb live load <br /> Determine maximum span: <br /> Ll/Ce=iāœ“(66.33'#/25psf) = 1.629 <br /> Assuming Ce=0.145: <br /> L= 1.629/(āœ“0.145) =4.28' (a/b =3/4.28 =0.70,Ce=0.145 okay) <br /> Check for concentrated load: <br /> Mep=2CoCe*P*b check based on uniform load dimensions <br /> Mep=2(1+0.7)1/3*0.145*50*4.28'=74.07'# <br /> Resisting width=4.28/2=2.14'<3' <br /> 74.07/2.14= 34.6 <49.75'# okay <br /> Verify Deflection: <br /> 36" wide lite(infill for 42"rail height) 25 psf <br /> Aa= iowb4/{910,746.8 psi *t3]} <br /> For a/b =0.70;'no=0.0158 <br /> Aa= 0.0158*25/144*514/{910,746.8 psi *0.2233]} = 1.84">0.02*43.84"=0.88" <br /> Deflection will exceed the limits of the Z-clamps to behave as designed so bending in clamps <br /> will increase accordingly. <br /> Revised bending in Z-clamps at 25 psf: <br /> H=25psf*4.28'*3'/4= 80.25# <br /> M= 80.25#*1.12" = 89.88"# >42.8"# <br /> Okay for the stainless steel Z-clamp only <br /> Maximum span for Zamak Z-clamp: <br /> Assume rho=0.0263 (square light) <br /> b= (Aa 910,746.8 psi *t3/(riow))1i4 <br /> b = [0.88*910,746.8t3)/(0.0263*25/144)]1/4= 37.35" <br /> FOR 1/4" GLASS <br /> Maximum glass length = 37 1/4" except; <br /> For stainless steel clamps maximum glass length= 51" <br /> EDWARD C.ROBISON,PE <br /> 10012 Creviston Dr NW <br /> Gig Harbor,WA 98329 <br /> 253-858-0855/Fax 253-858-0856 elrobison@narrows.com <br />