CALCS PROC015
LATTICE MEMBER, COMBINED LOADING

NOTATION

Actarea-chord,top
Acbbottom
Abtarea-brace,top
Abbbottom
Absside
y yframe height
z zframe width
x xcoord, brace pitch
Aarea-sum of four chords
Lbslength-brace,side
Lbtbtop & bottom
Abathoarea-batho
Px y zforces parallel to x y z axes
Mx y zmoments parallel to x y z axes
fa.trstress-chord,top right
fa.brbottom right
fa.blbottom left
fa.tltop left
fa.b.sstress-axial,brace,side
fa.b.ttop
fa.b.bbottom

APPLICATION

Lattice Beam type member

OUTPUT

Direct stresses in chords, braces & transversals

SEE ALSO

PROC010 PROC032 PROC040

THEORY

see proc

GUIDANCE

Parallel chords are assumed, acceptable for small taper angles

INPUT FORMAT

LET Nm=:Nk=:Act=:Acb=:Abt=:Abb=:Abs=:y=:z=:x=:Px=:Py=:Pz=:Mx=:My=:Mz=:PROC015

EXAMPLE

Call Statement

LET Nm=1:Nk=1:Act=31:Acb=43:Abt=6.8:Abb=8.3:Abs=5.1:y=75:z=90:x=120:Px=98:Py=3.5:Pz=2.7:Mx=700:My=4500:Mz=5430:PROC015

Output

PROC015 MEMBER, LATTICE, COMBINED LOADING, Rev 210995
A= 2*Act+2*Acb= 148
Lbs= SQR(y^2+x^2)= 141.5
Lbtb= SQR(z^2+x^2)= 150
Abatho= z*y= 6750
ftr= Px/A+My/(2*z*Act)-Mz/(2*y*Act)= 0.3009
fbr= Px/A+My/(2*z*Acb)+Mz/(2*y*Acb)= 2.085
fbl= Px/A-My/(2*z*Acb)+Mz/(2*y*Acb)= 0.9226
ftl= Px/A-My/(2*z*Act)-Mz/(2*y*Act)= -1.312
fbs= ABS(Py)*Lbs/(2*y*Abs)+ABS(Mx)*(Lbs/y)*y/(Abs*2*Abatho)= 2.086
fbt= ABS(Pz)*Lbtb/(2*z*Abt)+ABS(Mx)*(Lbtb/z)*z/(Abt*2*Abatho)= 1.475
fbb= ABS(Pz)*Lbtb/(2*z*Abb)+ABS(Mx)*(Lbtb/z)*z/(Abb*2*Abatho)= 1.208
UF= FNmax(ftr,fbr,fbl,ftl,0)/(Kd(Nk)*Fy(Nm))= 0.8893
UF= FNmax(fbs,fbt,fbb,0,0)/(Kd(Nk)*Fy(Nm))= 0.8896
END015