Pipe288 and elbow290 modelling for ovalisation
 

Hi,

Iim doing my 4th year project on ovalisation of a pipe (oil pipe underwater) and I'm having trouble writing the script. To describe it better " modelling buckling of a pipeline, buckling conditions(displacement, forces and strains) and post buckle performance (effects of ovalisation on serviceability) were investigated". A previous student used the GUI to construct the initial models and I'm using the log files to create a script.

I understand some of the log file through using ansys help but the structure is confusing. so far i've written this from the log file:

/PREP7

ET,1,PIPE288
KEYOPT,1,3,3
KEYOPT,1,4,1
KEYOPT,1,6,0
KEYOPT,1,7,2
KEYOPT,1,8,1

ET,2,CONTA178
KEYOPT,2,2,1
KEYOPT,2,3,3
KEYOPT,2,4,1
KEYOPT,2,9,1


R,1,1e-6, , ,0.4, , ,

MPDATA,DENS,1,,7800
MPDATA,EX,1,,2.09e11
MPDATA,PRXY,1,,0.3

SECTYPE,1,PIPE, ,
SECDATA,0.4,0.0175,32,0,1,0,0,0,

N,1,0,0,0
N,2,,,0.25
N,3,,,0.5
N,4,,,0.75
N,5,,,1

E,1,2
E,2,3
E,3,4
E,4,5



ANTYPE,4

TRNOPT,FULL
LUMPM,OFF



TIMINT,ON,STRUC
NSUBST, ,1/100,1/4,OFF
/EOF



D,P51X, , , , , ,ALL, , , , ,
FLST,2,991,1,ORDE,2
FITEM,2,1
FITEM,2,-991
!*
/GO
F,P51X,FY,-1727.5
FLST,2,990,1,ORDE,2
FITEM,2,1193
FITEM,2,-2182
!*

The sections with the FLST and FITEM commands I don't really understand but through the help it said they're outputted through GUI when manually selecting.

I've removed many variables as I'm trying to narrow the scope (thermal expansion, lay friction, short pipe section 1m instead of 200m etc). I don't also understand the applied forces as I'm given just internal and external pressure (unless it self calculates pressure to force but then why isn't the force uniform?).

So overall I'm quite lost has anyone got some tips/explanations/methods/code/etc that could help me? As there isn't too much available on pipes.

Regards
Reece