Wind load Ex.

Wind LoadWind Load Calculations for the design of tall towerInput Req.D1Diameter of the lower portion4ftInput Req.D2Diameter of the higher portion3ftInput Req.H1Length of the vessel section56ftInput Req.H2Length of the vessel section44ftInput Req.hTDistace from base to section under consideration4ftInput Req.PwWind pressure lb/ft^230lb/ft^2h1Lever arm ft=H1/228fth2Lever arm ft=H1+H2/278ftV1Shear force=Pw*H1*D16720lb3054.5454545454kgMaximum due to V1188160lb ftV2Shear force=Pw*H2*D23960lb1800kgMaximum due to V2308880lb ftTotal VTotal Shear force10680lbTotal moment497040lb ftMMaximum moment=V1h1+V2*h2497040lb ftMTMoment at the considered section at the tangent line=M-hT(V-0.5*Pw*H1*D1)455280lb ft616904.4Nm

Input Req.DDiameter of the lower portion3.5ftInput Req.HLength of the vessel section100ftInput Req.hTDistace from base to section under consideration4ftInput Req.PwWind pressure lb/ft^230lb/ft^2Input Req.Length of the ladder98ftInput Req.Distance of the plat from the base96h1Lever arm ft=H/250ftVesselVShear force=Pw*H*D10500lbf4772.7272727273kgMaximum due to V525000lb ftLadderVlShear force=Pw*H*D2940lbf1336.3636363636kgMaximum due to ladder144060lb ftPlatformVpShear force=Pw*H*D240lbf109.0909090909kgMaximum due to plat.23040lb ftTotal VTotal Shear Force13680lbfTotal moment692100lb ftMTMoment at the considered section at the tangent line=M-hT(V-0.5*Pw*H1*D1638220lb ft864788.1Nm

Vibration CheckInput Req.DOutside Diameter of the vessel3.125ftInput Req.HLength of the vessel section100ftg32.2 ft^2/sec32.2ft^2/secInput Req.tThickness of the skirt at the base0.75inVTotal shear1440lbsWWeight of the tower 36000lbswWeight of the tower per height of the tower 360lbf/ftTPeriod of vibration=0.0000265(H/D)^2w*D/t1.0509727608secTaAllowed period of vibration7.0490737685secCheckVibrations within the limitSeismic Load Earth QuakeInput Req.DOutside Diameter of the vessel3.125ftInput Req.HLength of the vessel section100ftInput Req.tThickness of the skirt at the base0.75inInput Req.WWeight of the tower 34000lbswWeight of the tower per height of the tower 340lbf/ftInput Req.XDsitace from the top tangent line to the bottom section under consideration96ftTPeriod of vibration=0.0000265(H/D)^2w*D/t1.0213619352secFrom TableCSeismic Coefficeint0.04MMoment at the base 90666.67ft-lb122853.333333333NmMxMoment at the section85229.57ft-lb115486.06464NmVShear Force=C*W1360lbs618.1818181818Kg

Eccentric loadEccentric Load

Input Req.eEccentricity4ftInput Req.RMean radius of the vessel15inInput Req.tThickness of the vessel excluding the corrosion allowance0.25inInput Req.WEccentric Load1000lbSStress value of the mat.Actual bending Stress=12*W*e/(R^2**t)271.5151515152psi

Elastic StabilityElastic StabilityInput Req.R Mean radius of the vessel18inInput Req.tThickness of the shell0.25inInput Req.AxCrossectional area of one longitudanl stiffner0Input Req.AyCrossectional area of circumferrential stiffner1sqin.Input Req.dxDistance between longitudnal stiffner1Longitudanl stiffner is not usedInput Req.dyDistance between circumferrential stiffner24intxEquivalent thickness of the stiffner when longi.st. is used0.25tyEquivalent thickness of the stiffner when circum.st. is used0.292inSAllowable stress with out the stiffner20833.33psiSAllowable stress with the stiffner22502.57psi

DeflectionDeflection in the long tower

Input ReqD1Diameter of the vessel with insulation2.5ftEModullus of Elasticity30000000Input ReqHLength of the vessel including the skirt48ftI Momemt of inertia=22/7*R^3*t1697.14in^4Input ReqPw Wind pressure30psiInput ReqRMean radius of the tower12inInput ReqtThickness of the skirt0.3125inMMaximum deflection(Actual)=PwD1H(12H)^3/(8EI)1.69inMaximum deflection allowable2.88inCheckDeflection is within limits

Sheet1

Sheet2