Determine pipeline behaviour

Function ready condition: All 'Required' input data tables tested. In case of soil the 'Conditional' input data table SOILCTL tested. In case of geom. non-linear calculations GEOMCTL tested.

Function error condition: 35 error conditions, 35 warning conditions, 6 messages

No 'press' load component specified

A LOAD FACTOR is > 0. and the corresponding load component has not been specified in the previous function.

• | load factor 'PRESS' > 0. without 'PRESS' load component specification |

No 'temp' load component specified

A LOAD FACTOR is > 0. and the corresponding load component has not been specified in the previous function.

• | load factor 'T-DIF' > 0. without 'TEMP' load component specification |

No deadw' load component specified

A LOAD FACTOR is > 0. and the corresponding load component has not been specified in the previous function.

• | load factor 'DEADW' > 0. without 'DEADW' load component specification |

No 'setl' load comp. specified

• | load factor 'SETL' > 0. without 'SETX/Y/Z' or 'SUBSIDE' load component specification |

No 'nodal' load component specified

• | load factor 'NODAL' > 0. without 'NODAL' load component specification |

Singularity at node 'number' comp.(onent) xy

During the calculation process a main diagonal element ≤ 0. is found.

xy: | The component indicator x = T (translation) first 3 comp. x = R (rotation ) secnd 3 comp. y = X (in or around X-axis) y = Y (in or around Y-axis) y = Z (in or around Z-axis) |

The error conditions E500/1-5,9,20 are detected before the calculation process starts resulting in a questioned table LOCASE, error condition E500/6 may occur during the calculation process. In both cases the output data tables are not produced, except for table BENDFAC at error E500/6 if there are bends.

Elas bend in geo-nln module only

Elastic bends have been specified in both table POLYDIF and LOCASE, but the geometrically non-linear module is not present.

• | input table LOCASE will become questioned |

• | output tables will not be produced |

Elas bend in geo-nln calculation only

Elastic bends have been specified in both table POLYDIF and LOCASE, and the calculations are specified as linear (GEO-LIN).

• | output tables will not be produced |

No elastic bends specified

Elastic bends are taken into account in input table LOCASE, but they have not been specified in input table POLYDIF.

• | input table LOCASE will become questioned |

• | output tables will not be produced |

Project parent not found

It is specified that data must be taken from a parent project, but that database is not present.¹

Project parent without displacements

It is specified that the displacements must be taken from a parent project whereas displacements are not present in that project.¹

Number of nodes not identical

It is specified that data must be taken from a parent project with a number of nodes different from the current project.¹

Rotation greater than 0.3 rad

A rotation greater than 0.3 radians has been calculated with GEO-NLN and the non-linear module for large displacements is not present.

• | output table DISPLAC will be produced but is meaningless |

• | the problem can be solved with the Large Displacements module (L) only |

Infin node without soil friction

At an INFIN boundary element with a gradient no axial soil friction has been specified and pipe deadweight is taken into account.

• | output tables will not be produced |

(The deadweight of the infinite boundary pipe has an infinite axial component without counteraction from the soil.)

Continue after Phasing not possible

The parent project to copy data from has been run with the Phasing option and in the current run the Continue option has been specified.¹

External pressure > critical one

The external pressure is greater than the critical one.

• | output tables will not be produced |

(The influence of the soil is included.)

Element 'number' length too large

The rotation difference between the nodes of an element > 0.6 rad.

(The element length in question should be reduced.)

Focus node has neared focus point

In a geometrically NON-LINEAR calculation the displacement of the focus node is such that the focus node (virtually) coincides with the focus point.

(The direction of the focus load has become indeterminate and further calculations are not possible.)

out-of-date

No 'wave' load component specified

The WAVE load factor is > 0. and the corresponding load component has not been specified in the previous function.

• | load factor 'WAVC' > 0. without 'WAVE/CURRENT' load component specification |

Fixed after non-fixed node with connects

A boundary node has been specified as FIXED in the current phase and that node has been displaced in previous phase(s) while the pipeline contains CONNECTED sections and the calculations are LINEAR.

(This error can be avoided by using the geometrically NON-LINEAR option.)

Cond node not found in previous phase

A boundary/condition node number in the current phase is not a boundary node in the previous phase.

(In consecutive phases the type of boundary nodes (condition) may be changed (e.g. from FREE to INFIN) but not the location.)

No room for connect vectors

The number of connected points is relatively high.

(The pipeline configuration is too complex to calculate. There is not enough memory and disk space available for the connect vectors.)

Tfsprs supports only with geo-nln

A table friction support has been specified while the pipeline calculations are geometrically LINEAR.

(This error can be avoided by using the geometrically NON-LINEAR option.)

Mat-nln not allowed for anisotropic mat.

Anisotropic material has been applied while the pipeline calculations are specified as elasto-plastic.

(Anisotropic material has no elasto-plastic properties.)

NEN rerounding functions critical

The calculations are performed according to NEN 3650 and there is a external pressure resulting in infinite bend flexibility.

(The (negative) external pressure is so high that the bend flexibility and stress intensification factors resulting from the rerounding formulae in NEN 3650 become infinite due to division by zero or negative.)

Non-general method with LBA/OVL

The Code option key is not in the GENERAL position and the calculation method option keys have been set to LBA and/or OVL.

(The LBA/OVL option is an advanced option that does not (yet) fit into the current Code regulations.)

Ovalisation > 25 % of diameter

The ovalisation of the pipe cross-section exceeds a quarter of the pipe diameter.

(It's no use to make further calculations because there is a great risk of disruption of the cross-section.)

Actual bend radius < diameter

The calculation options have been set to GEO-NLN and OVL and a PIPE or BEND element has been deformed such that the calculated radius of curvature is less than the average diameter.

(The deformation of the pipeline is such that it's no use to make further calculations.)

Critical buckling strain less than zero

The sum of internal and external pressure is such that the critical buckling strain becomes less than zero.

(The critical buckling strain due to compression and/or torsion is determined according to the formulae in code NEN 3650. The error message is given if the occurring total pressure is negative such that the critical buckling strain becomes (less than) zero.)

Hoop stress > yield

The calculated hoop stress exceeds the yield stress in calculations according to the plasticity theory.

(The cross-section of the pipe will fail in this case.)

Phase mat-lin after mat-nln not possible

With the Phasing option selected, the current project is materially elastic and the parent project is materially plastic.

(For the time being this phase transition is not allowed.)

Joints in geo-nln calculation only

Joints have been specified in input tables PIPES and JOINTS, and the calculations are specified as linear (GEO-LIN).

• | output tables will not be produced |

Bend parameter less than 0.10

The bend parameter Lambda during calculations with option IBA or LBA is less than 0.1.

(The bend parameter value should not be less than 0.1, because the modeling of the bend behaviour becomes too inaccurate.)

Bend parameter less than 0.01

The bend parameter Lambda during calculations with option OVL or MAT-NLN is less than 0.01.

(The bend parameter value should not be less than 0.01, because the modeling of the bend behavior becomes too inaccurate.)

Iteration criterion not satisfied

With the 'Section Model: Ovalising' option, first a Non-Ovalising calculation is performed. When, after the maximum number of iterations, the (Non-Ovalising) iteration criterion is not satisfied, the Ovalising calculation will not be performed, because the results would most probably be unreliable.

The same counts for the 'Material Model: Non-Linear' option; first a Non-Ovalising calculation is performed, then an Ovalising calculation and finally a Material Non-Linear calculation. When one of the first two calculations does not satisfy the criterion, the Material Non-Linear calculation will not be performed, because the results would most probably be unreliable.

SiS only possible with geo-nln calc.

At least one SiS section has been defined in table SISSECT, and the calculations are specified as linear (GEO-LIN).

Not all load factors according NEN3650

It is specified on the main menu screen that calculations must be per- formed according to NEN3650 and a load factor in table LOCASE is not according to the prescribed value in NEN3650.

(The general load factor has been taken into account!)

Iteration criterion not satisfied

After the iteration process has been ended the iteration criteria have not been fulfilled.

Non-linear infin node

After the iteration process non-linear behaviour of one of the boundary points with a half-infinite long connected pipeline is observed.

Equilibrium not correct - or - equilibrium nearly correct

After the iteration process has been ended the equilibrium does not fulfil the equilibrium criterion.

(Equilibrium is nearly correct if norm difference between 1.E-6 and 1.E-3, and not correct if norm difference > 1.E-3. See Theor. Man.)

Rotation greater than 0.3 rad

After the geometrically LINEAR calculation process a rotation at a node is greater than 0.3 radians (about 17 degrees).

(It is probable that the calculation results are less accurate.)

Instability within elements

It turns out after the geometrically non-linear iteration process that the influence of axial (compressive) forces on the element stiffness has been switched off in view of occurring buckling.

(A 'stable' configuration has been found only by neglecting the influence of the 'stress weakening' of the elements.)

Element 'number' length very large

The curvature of an element is such that the rotation difference between the nodes of that element exceeds 0.2 radians.

(It is recommended to subdivide element number 'number' in several shorter elements.)

External pressure 'value' % of critical

The external pressure is greater than 50 % of the critical one.

('value' between 50 and 100. Influence of soil pressure is included.)

Displacement database with slack

In the design to copy the displacements from slack values have been specified and the current design contains no slack values.

Displacement database without slack

In the design to copy the displacements from no slack values have been specified and the current design contains slack values.

Displacement database non-linear

The design to copy the displacements from is geometrically non-linear and the current design is linear.

Displacement database linear

The design to copy the displacements from is geometrically linear and the current design is non-linear.

Hystrss-run, infin soil values not equal

In case of HYSTRSS option the soil properties at an INFIN end node of the previous and the current design database are different.

Hystrss-run, fixed node changed to infin

In case of HYSTRSS option a FIXED end node of the previous design has been changed to INFIN in the current design.

Hystrss option without soil

In case of HYSTRSS option there is no soil in the current phase.

Nonlin infin node at start of phase

The current design starts from the displacements of another design containing an INFIN boundary node with non-linear behaviour.

Support spring large

The support stiffness exceeds 1000 times the pipe stiffness.

(When the support spring is relatively large, it may require a great number of iterations to find equilibrium.)

Hoop stress > yield

The calculated hoop stress in a section exceeds the yield stress.

Hoop stress 'value' % of yield

The calculated hoop stress in a section exceeds 70% of yield.

Load factors changed at restart

After an iteration a load factor in table LOCASE is changed and then the function is restarted using the unlock facility.

Number of connects not equal

The number of connected points in the current phase differs from that in the previous phase.

(The basic configuration of the pipeline has been modified in the current phase and this may not be intended.)

Forces on infin from last free open

A boundary node was specified as FREE and OPEN and a pressure or temperature load was existing in one of the previous phases and that boundary node has been changed to INFIN in the following/current phase.

(In the in-between phase a half INFINite long pipeline with pressure or temperature is linked to the FREE end without causing displacements. To achieve this forces are applied on the INFIN node.)

Vertical element or node axis

After the calculations one or more elements have (become) a vertical direction (DXY/L < 0.001).

(A vertical element has a different local coordinate system!)

ELEM-L/ADV-L 'value', 'number' ('number1' - 'number2')

An element length is more than 4/3 the recommended length.

value = maximal occurring element length quotient (>4/3)

number = element number with reported length quotient

number1, number2 = start, end of elem. series with quotient >4/3

(The inaccuracy is over 5%. See Theoretical Manual, chapter 2.3.)

Press-factor for bending stiffness 1.

Calculations are performed for a pipeline with bend(s) according to NEN 3650 and the pressure factor in table LOCASE is less than 1.

(For determination of the influence of the rerounding on the flexibility and stress intensification in bends the pressure without factor has been taken according to NEN 3650.)

Rot-dif connect 'name', 'value' rad

The ROTations or TRaNslations of connected points differ.

Trn-dif connect 'name', 'value' 'title'

The ROTations or TRaNslations of connected points differ.

(name = IDENT of connection value = value of difference in radians or length unit title = current unit of length. This warning will occur only in exceptional cases.)

Ovalisation is 'value' % of diameter

The ovalisation of an element exceeds 10% of diameter.

(An ovalisation exceeding 10% is considered to be very large.)

Elastic bends calculated as normal bends

In table POLYDIF one or more bends have been specified as ELAStic and the loadfactor for elastic bends ELBND-F in table LOCASE is zero.

(Probably this is unintended and an input error.)

Hystrss-run, iter. crit. not satisfied

The iteration criteria in one or more of the previous hysteresis phases have not been satisfied.

(It is possible that in the current phase the iteration criteria are satisfied, but the results obtained are based on less accurate results from previous phases.)

Number of joint elements not equal

The number of joints in the current phase differs from the number in the previous phase.

Number of weak elements not equal

The number of weak elements in the current phase differs from the number in the previous phase.

Physical non-linearity in infin element

In one or more of the boundary elements connected to an INFIN pipeline yielding of the pipe material occurs (plastic deformation).

(The modelling of the INFIN boundaries is linear and therefore the behaviour of the boundary elements should be linear as well.)

Leaking joint(s)

The translation and/or rotation of a socket-spigot connection or a double socketed coupling sleeve without stop is such that the maximum specified values have been exceeded.

(This effect of the displacements in the joint(s) is also reported in output table DISPJNT.)

Bend parameter less than 0.15

The bend parameter Lambda during calculations is less than 0.15.

SIS‘id’ ‘num’ dist. ‘value’ at ‘num2’

The specified SIS section has a maximum distance larger than 10 mm between the axes of the inner and outer pipe of ‘value’ mm between node ‘num’ on the inner pipe and element ‘num2’ of the outer pipe.

(Per SIS section only the maximum distance between the axes is reported.)

SIS‘id’ ‘num’ fact. ‘value’ at ‘num2’

The outer diameter of the inner pipe of the specified SIS section falls outside the inner diameter of the outer pipe. The factor is the ratio of the combined (perpendicular) displacements of inner and outer pipe vs half the originally specified space between outer diameter of the inner pipe and inner diameter of the outer pipe.

(Per SIS section only the maximum factor is reported. ‘Num’ is the node on the inner pipe and ‘num2’ is the element of the outer pipe where the maximum factor occurs.)

SIS‘id’ rol ‘num’ dist. ‘value’ mm at ‘num2’

The specified SIS section has a maximum distance larger than 1 mm between the axes of the inner and outer pipe of ‘value’ mm between node ‘num’ on the inner pipe where a roller has been defined and element ‘num2’ of the outer pipe.

(Per SIS section only the roller with maximum distance is reported.)

Roller ‘num’ displaced out of PipeOut‘id’

There no longer is an intersection between the plane perpendicular to the outer pipeline axis and the inner pipe section at node ‘num’. In general this means the node on the inner pipeline of the SIS partially restrained connection has moved outside the outer pipe.

SIS‘id’ inner ‘num’ not fit outer ‘num2’

The specified SIS section has an inner pipe element ‘num’ that does not fit in the accompanying element of the outer pipe ‘num2’.

(Per SIS section only the first not-fitting element is reported.)

W500/92:

No Soil, table 'table' ignored

The bend parameter Lambda during calculations is less than 0.15.

Rotation > 0.3 rad during iteration

During the geometrically LINEAR calculation process a rotation at a node is greater than 0.3 radians (about 17 degrees).

(At the end of the iteration process the rotation may be less again.)

Possible instability (iter. 'number')

During one of the iterations of the calculation process the pipeline structure becomes less stable.

(After completing the calculation process the pipeline structure is stable or the iteration criteria are not (yet) satisfied.)

Non-linear infin node during iteration

During the iteration process non-linear behaviour of one of the boundary points with a half-infinite long connected pipeline is observed.

(At the end of the iteration process the INFIN nodes behaviour may be linear again.)

Instability within element during iter.

It turns out during the geometrically non-linear iteration process that the influence of axial (compressive) forces on the element stiffness has been switched off in view of occurring buckling.

(At the end of the iteration process the influence of the 'stress weakening' of the elements has been taken into account again.)

Press-factor for bending stiffness 1.

Calculations are performed for a pipeline with bend(s) according to NEN 3650 and the factor for the pressure in table LOCASE is greater than 1 as should be the case normally.

(For determination of the influence of the rerounding on the flexibility and stress intensification in bends the pressure without factor has been taken according to NEN 3650.)

ELEM-L/ADV-L 'value', 'number' ('number1' - 'number2')

An element length is more than the recommended length.

(value = maximal occurring element length quotient (>1 and <1.34) number = element number with reported length quotient number1, number2 = start, end of elem. series with quotient >1)

¹ output tables will not be produced

H5004, last changed: 2009-01-15

See also: