Bell mouth model nodal system

The input to this model can be found in the example folder, under case E003.

A section of flexible pipe with bell mouth is defined. The model is rigidly fixed in all degrees of freedom at the top/root of the bell mouthr. The pipe is exposeed to:

tension applied at the lower end
external and internal pressure
bending; applied by transverse loading at the lower end

Figure 1. Bflex model

Model description

The model, see Figure 1, consist of thermal layers, carcass and zeta spiral that are specified based on the cross sectional area and with no detailed geometry.

#            NAME     TYPE       IFRIC  DISFAC  FORFAC  GEOFAC  ENDFAC  ID          TIMEINI  ITCODE  ELIDNUMBER  IELBFL  FIMOD  CONTDEN  NELGR  EL1GRP   EL2GRP       EL3GRP        
CROSSECTION  NYEMAT   FLEXCROSS  2      1000    2       0       0.0     0.1524E+03  2        31      14          1       0.0    0.0      3      NYECORE  NYETENSILE1  NYETENSILE2
# CTYPE  THK         MATNAME      FRIC   LAY-ANG   RNUM  TEMP  MATNAME_NL  CCODE     CFATFL  AREA       IT  INY  IRKS  WIDTH
CARC     6.0000E-00  CARCMAT      0.15   88.1153   1     0.00  none        MANUAL    NONE    0.456E+02  0   0    0     0    
THER     1.1940E-00  THERMAT      0.15   0.0000    0     0.00  none        NONE      NONE    0          0   0    0     0    
THER     6.5000E-00  THERMAT      0.15   0.0000    0     0.00  none        NONE      NONE    0          0   0    0     0    
ZETA     1.0000E+01  ZETAMAT      0.15   88.9395   1     0.00  none        MANUAL    NONE    0.950e+02  0   0    0     0    
THER     2.6667E-01  THERMAT      0.15   0.0000    0     0.00  none        NONE      NONE    0          0   0    0     0    
THER     9.4340E-01  THERMAT      0.15   0.0000    0     0.00  none        NONE      NONE    0          0   0    0     0    
TENS     5.0000E-00  TENSMAT      0.15   30.2774   40    0.00  none        TENSILE1  SNTENS  0          0   0    0     0    
THER     9.4340E-01  THERMAT      0.15   0.0000    0     0.00  none        NONE      NONE    0          0   0    0     0    
THER     2.5000E-01  THERMAT      0.15   0.0000    0     0.00  none        NONE      NONE    0          0   0    0     0    
TENS     5.0000E-00  TENSMAT      0.15   -30.6543  42    0.00  none        TENSILE2  SNTENS  0          0   0    0     0    
THER     1.9029E-00  THERMAT      0.15   0.0000    0     0.00  none        NONE      NONE    0          0   0    0     0    
THER     6.0000E-00  THERMAT      0.15   0.0000    0     0.00  none        NONE      NONE    0          0   0    0     0    
THER     3.8835E-01  THERMAT      0.15   0.0000    0     0.00  none        NONE      NONE    0          0   0    0     0    
THER     6.0000E-00  THERMAT      0.15   0.0000    0     0.00  none        NONE      NONE    0          0   0    0     0

A bell mouth is defined by the element type body502, which is a rigid body that can act as a contact surface. The geometry of the bellmouth is spesified as two segments; one cylinder and a bellmouth section with increasing radius:

#       ELGRP          TYPE   GEOM                                                                                                                       
ELPROP  NYEBELLMOUTH   BODY   GEO_BM  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0
#
#     NAME    NSEG  TYPE       THETA   NVIS  LEN     DIAM1      DIAM2 
GEOM  GEO_BM  2     CYLINDER   0.0000  20    2.0E+3  0.280E+03  0.280E+03
#                              THETA   NVIS  LEN     DIAM       RADSTART      RADEND   PHI0 
                    BELLMOUTH  0.0000  60    6.0E+3  0.280E+03  50.0E+03      50.0E+13      0.00

The bell mouth is connected to node 1, which is the upper node of the pipe model.

The geometry is described based on the mid point of the first segment, which is at distance 1000. For the geometry to start a the position of node 1, an eccentricity is specified for the bell mouth element (element 5001):

#       TYPE   ELID   ELIDEND  XECC  YECC  ZECC  
ELECC   BEAM   5001   1        1.0E+03   0.0   0.0

A conctact element gruoup is defined between the bell mouth and the pipe:

#      ELGR            ELTY     MATNAME      ELID  NOD1
ELCON  BM_CONT_GRP     CONT152  BM_CONT_MAT  6001  1
                                             6080  1
#
#         TYPE         ELID        X    Y    Z
ELORIENT  EULERANGLE   6001        0.0  0.0  0.0                
                       6080        0.0  0.0  0.0                
#
#       TYPE   ELID   ELIDEND  XECC  YECC  ZECC  
ELECC   BEAM   6001   1        1.0E+03   0.0   0.0
REPEAT 80 1
#
#        ELGRP        MASTENAME     SLAVENAME  IS1  ISN  TX  TY  YZ  MAXIT  IGAP
CONTINT  BM_CONT_GRP  NYEBELLMOUTH  NYECORE    1    401  2   2   2   60     1   
#
#       ELGRP       TYPE       RD        INSIDE   
ELPROP  BM_CONT_GRP BELLMOUTH  253.17744 -1.0000

By the elcon definition a total of 80 body contact elements cont152 are applied, all working on the body connected to node 1.

The contint definition specifies which pipe nodes that are relevant for contact. A search is done to setting up contact element with the 80 pipe nodes that are closest to the node of the bellmouth geometry.

The same eccentricity must be used as when defining the eccentricity of the body.

It is possible to update the contact search at a later time by an optional parameter on the contint description.

Results

The curvature profile is obtained by glplot from bflex2010post, and shown at maximum displacement in Figure 2.

Figure 2. Curvature profile

Relevant files

Go to bflex2010 file

Go to bflex2010post file

User manual for reference

Processing of files from command line

bflex2010 -n bflex2010_01
bflex2010post -n bflex2010post_01

Back to index

→ To index