CALCS PROC010
CHORD-BRACE JOINT

NOTATION

Qgnot less than 1.0
Q'beta= .3/(beta*(1-.833*beta)) ...beta>.6
Q'beta= 1.0...beta<.6
Quaxial comp. K type joint
Ddiameter, chord
Tthickness, chord
ddiameter, brace
thetaincluded angle, brace to chord
ggap, between braces
P1force, brace
Momoment, o-o-plane
Mimoment, in-plane
IDlamdindicator, lamda
IDqfindicator, qf
lamdafactor, qf
gamaD/2T
betad/D
Uchord utilisation
Qfchord load factor
Qgcoefficient, K joint
Q'betageometric modifier
Karelative length factor
Pkcharacteristic axial strength

APPLICATION

Tubular joints formed, without the use of gussets, diaphragms, stiffeners or grout, by the full penetration welding of two or more tubular members.

OUTPUT

Chord local bending & axial stress

SEE ALSO

PROC015 PROC032 PROC040

THEORY

DoE Offshore Installations, Guidance on Design, Appdx A21
API 2A(RP2A)

GUIDANCE

Formulae for Qf varies with IDqf (1or2) and Qbeta with beta ( < or > .6)
The procedure is presently configured only for K type joint brace ax force effects.
The three values of IDlamda 1, 2 & 3 correspond to particular loading conditions:
IDlamda lamda Condition
1) .03 brace axial force
2) .045 brace in-plane moment
3) .021 brace out-of-plane moment
The two values of IDqf relate to loading conditions:
IDqf Condition
1 operation
2 ultimate
Use following safety factors: extreme 1.28, operating 1.7

INPUT FORMAT

LET Nm=:Nk=:D=:T=:d=:theta=RAD():g=:lamda=.03or.045or.021:IDqf=1or2:P1=:Mo=:Mi=:PROC010

EXAMPLE

Call Statement

LET Nm=1:Nk=1:D=150:T=2.5:d=55:theta=30:g=21:lamda=.03:IDqf=1:P1=21:Mo=265:Mi=298:PROC010

Output

PROC010 CHORD-BRACE JOINT, Rev 200995
gama= D/(2*T)= 30
U= SQR((.23*P1*D)^2+Mi^2+Mo^2)/(.72*D^2*T*Fy(Nm))= 5.834E-3
Qf= 1-2.89*lamda*gama*U^2= 0.9999
beta= d/D= 0.3667
Qg= 1.7-.9*SQR(g/D)= 1.363
Qbeta= 1.0= 1
Qu= (2+20*beta)*Qg*SQR(Qbeta)= 12.72
Ka= (1+1/SIN(theta))/2= -6.057E-3
Pk= Qu*Qf*Fy(Nm)*T^2*Ka/SIN(theta)= 1.706
UF= P1/((1/1.28)*Pk)= 15.7615.76
UF= P1/((1/1.7)*Pk)= 20.9320.93
END010