Railway fastener modelling: Error concerning the wires elements CONN3D2 during Data Check.

[omar.el92]

Greets to everybody, i'm really new to the ABAQUS software and this is my first topic.

For my master thesis project i'm modelling a FE model of a railway track and wheelset in order to perform a parametric analysis of the rail corrugation mechanism.

In order to model the fastening system, i've considered the railpad as solid, with a tie connection with the sleeper below and a surface-to-surface contact with the upper rail. The fastening springs are modelled as wires between two reference points, as shown in the picture.
The upper one is coupled (Continuum distributing) with the sleeper surface, while the lower one is coupled (Continuum distributing as well) with the rail foot surface.

The wire section is an elastic axial with an initial length longer than the actual wire in order to simulate the precompression of the screw.
The rail is 36m long. The wire has been created along the rail by using a python code.

When i run the Data Check i get the following error:

*ELEMENT, file "Static_Analysis_Attempt1.inp", line 1027548: Element number is not an integer or exceeds 9 digits for element of type CONN3D2".

I really have no clue about what could be the matter, i modelled a very simple model with the same structure and works perfectly.

Anybody could help me figure out the soultion of this dilemma?

Thanks in advance!
Cheers.

Omar

 

[Mustaine3]

Check that mentioned line and also the line before and after. There is something wrong in the definition. Maybe just a comma is missing, maybe something else.

 

[omar.el92]

I checked the .inp file and it seems like the ABAQUS compile it in the wrong way. The definition of the elements miss the CONN3D2 nodes.

*Element, type=CONN3D2
6147, *Connector Section, elset=_PickedSet107752, behavior="Fastening Spring"
Axial,

In the working simple model the line is as following:

*Element, type=CONN3D2
5761, 1 ,481
*Connector Section, elset=_PickedSet107366, behavior="Fastening Spring"
Axial,

Do you have any idea why ABAQUS makes this error?

Thank you.

 

[omar.el92]

[SOLVED]

The issue was due to my Python iteration for the definition of the wire elements; indeed, i used simply the coordinates of the nodes in order to define them and obviously ABAQUS couldn't find them during the input writing.

r1 = mdb.models['Model 3_0-Pad_Fastener_SOLID'].rootAssembly.referencePoints

a.WirePolyLine(points=((r1[87457]), (r1[87937]),), mergeType=IMPRINT, meshable=OFF)

Regards,

Omar