FEM

Tekla Structures FEM import and export tool support several formats and provide several options for importing and exporting models.

FEM (Finite Element Method) is an analysis and calculation method used in structural engineering. In this element method, the target is divided into appropriate finite elements interconnected at points called nodes.

You can import the following formats into Tekla Structures using the FEM import tool.


Option	Software
DSTV	DSTV format data (Deutsche Stahlbau-Verband). Several different systems, for example, RSTAB static software and Masterseries Analysis & Design system. DSTV manufacturing format is the standard format used for manufacturing steel components on numerically controlled (NC) machines. It also has an Analysis & Design format that is used for transferring Analysis & Design models to the physical 3D model. Different programs produce different DSTV files. For example, the DSTV file produced by RSTAB static software only contains a static model. Tekla Structures exports either the static model (CROSS_SECTION), or the CAD model (MEMBER_LOCATION).
SACS	SACS modeling and analysis software
S-Frame	Analysis software, for example, FASTSOLVE
Monorail	Monorail system
STAAD	STAAD format data (Structural Analysis And Design). STAAD modeling and analysis system. FEM import is an old way to import STAAD data. We recommend that you use a direct link to ISM or STAAD.Pro, which are available in Tekla Warehouse. If Tekla Structures and STAAD.Pro or ISM are loaded onto the same machine then direct links can be used. To make a STAAD input file compatible with the Tekla Structures STAAD import, use the option Joint coordinate format (Single) to save the input file in STAAD. This creates a line for each coordinate in the input file.
Stan 3d	Stan 3d analysis software
Bus	BUS 2.5 analysis software

Import FEM

On the File menu, click Import > FEM.
In the New Import Model dialog box, select Import FEM.
Select import model (default) from the list or enter a new name.
Click OK.

Click Properties... to open a dialog box where you can define the settings for the import file:


Setting	Description
Conversion tab
Profile conversion file Material conversion file Twin profile conversion file	Define the conversion files you want to use. The maximum conversion file path length is 255 characters. Conversion files map Tekla Structures profile and material names with names used in other software. For more information about conversion files, see Conversion files.
Parts tab
Part Pos_No Assembly Pos_No	Enter a prefix and a start position number.
Parameters tab
Input file	The name of the file you want to import. You can also browse for the file. The maximum folder path length is 255 characters.
Type	Select the input file type: DSTV, SACS, Monorail, Staad, Stan 3d, Bus
Origin X, Origin Y, Origin Z	Define the origin coordinates to place the file in a specific location.
Default yield stress limit Default material when yield stress >= limit Default material when yield stress < limit	The Default material when yield stress < limit setting is used for SACS import file. Define the material to use if yield stress is less than the limit. The setting Default material when yield stress >= limit is used for SACS or DSTV import files. For SACS, this field defines the material to use if yield stress is greater than or equal to the limit. For DSTV you can enter the material grade here, if it is not included in the import file.
Combine members Max length for combining	To combine several elements in the FEM model into one part in Tekla Structures, set Combine members to Yes. For example, if a beam in a file consist of more than one element, and you select Yes, the elements are combined to form one beam in the Tekla Structures model. If you use the value No, Tekla Structures creates a beam for each element in the FEM model. Max length for combining is only applied if you set Combine members to Yes. Use this setting to define the maximum length for combining parts. Tekla Structures combines elements into one part only if their combined length is less than the value you enter here.
Staad tab
Material	Select the material grade.
Report tab
Create report	Set to Yes to create a report.
Display report	Set to Yes to display the report.
Report template	Select the report template. Your can also browse for the template.
Report file name	Enter the report file name or browse for a report file. If you do not give the report any other name, the report is saved with the name import_revision_report.rpt in the model folder.
DSTV tab
Version	Select the DSTV version.
Import static elements Import other elements	If the DSTV file to be imported contains a static and a CAD model, you can choose which one to import. Answering Yes to Import static elements imports the static model. Answering Yes to Import other elements imports the CAD model.
Stan 3d tab
Scale	Specify the scale of the import model. You can import Stan 3d without specifying the scale as long as both the Tekla Structures model and the import model are in millimeters. If the Stan 3d file is in millimeters, use the scale 1. If the Stan 3d file is in meters, use the scale 1000.
Material	Enter the material for the parts to import.
Bus tab
Pos_No	Indicate the Pos_No of the girders, columns, braces and cantilevers you import.
Material	Enter the material for the parts to import.
Name	Enter the name of the parts to import.
Class	Enter the class of the parts to import.
Beams behind plane	The value Yes aligns the tops of all beams at the floor level.
Advanced tab
Action when objects status is (compared to)	Previous plan lists the objects in your model, compared with the objects in the file to be imported. They can be New, Modified, Deleted, or Same. Tekla Structures compares the state of imported objects with those in your model. They can be Not in model, Different, or Same. Use the options under Not in model, Different, and Same to specify the actions when importing changed objects. The options are No action, Copy, Modify, or Delete. Usually there is no need to change the defaults.

Click OK to go to the Import Models dialog box.
Select the model to import.
Click Import.

Tekla Structures displays the Import model info dialog box.
Select which version of parts to import.
Click Accept all.

If you have changed the model and want to re-import it, you can also reject all changes by clicking Reject all, or accept or reject individual changes by clicking Select individual...
Tekla Structures displays the message Do you want to save the import model for subsequent imports? Click Yes.

Tekla Structures displays the import model in a model view.
Right-click the model view and select Fit work area to entire model to ensure that the imported model is completely visible.
If parts are missing, check the Depth up and Depth down values in the View Properties dialog box and change them if necessary.

Export FEM

Open a Tekla Structures model.
On the File menu, click Export > FEM.

The Export FEM dialog box opens.
Go to the Conversion tab and enter the names of the conversion files, or browse for the files.
Go to the Parameters tab, and enter the name of the output file, or browse for the file.
Select the output file type: DSTV, MicroSAS or Staad.
Set Split members to Yes to split a part in the Tekla Structures model into several elements in the exported model.
If you are exporting to MicroSAS, set Combine segmented members (MicroSAS) to Yes to combine multiple parts to form one part in the exported model.

For example, if you have divided a beam into several elements and select the Yes option, Tekla Structures combines the elements so that they form one beam in the exported model. With the option No every element of the beam in the model forms individual beams.
If you are exporting to Staad, go to the Staad tab:
- Select an option from Profile table list.
- Use the setting Parametric shapes when possible to define how Tekla Structures exports the profiles PL, P, D, PD, SPD to Staad. Yes exports the profiles as parametric shapes so that STAAD can identify them correctly. No exports all profiles as standard STAAD shapes.
  
  Example of a plate PL10*200 when exported as parametric shape (Yes):
  
  13 PRI YD 200.000000 ZD 10.000000.
  
  Example of the same plate exported as a standard shape (No):
  
  13 TABLE ST PL10*200
If you are exporting to DSTV, go to the DSTV tab:
- Select the DSTV version from the version list.
- In Element reference with, select whether you want to export into a static model (CROSS_SECTION), or into a CAD model (MEMBER_LOCATION).
Select the parts in the model to export.
Click Apply and Create.

Tekla Structures creates the export file in the current model folder.

Supported DSTV entities

The DSTV entities are listed below. Tekla Structures supports those marked with an asterisk (*). See the DSTV standard "Stahlbau - Teil 1. März 2000" for more information.

Static data:

vertex (*)

polyline

substructure (*)

node (*)

element (*)

element_eccentricity (*)

raster

boundary_condition

elastic_support

nodal_reaction

element_reaction

General data:

material (*)

cross_section (*)

CAD data:

member (*)

member_location (*)

construction-data

cutout

hole

STAAD table type specifications

Tekla Structures supports the following STAAD table type specifications:

ST (single section from the standard built-in tables)
ST PIPE (parametric)
ST TUBE (parametric)
RA (single angle with reverse Y_Z axes)
D (double channel)
LD (long leg, double angle)
SD (short leg, double angle)
TC (beams with top cover plates)
BC (beams with bottom cover plates)
TB (beams with top and bottom cover plates)

You can import the types CM and T, user-provided steel table types (UPT), and other non-standard profiles, if you have defined them in the profile conversion file. You must use the underscore character in the STAAD name, for example, UPT_1_W10X49. Tekla Structures automatically converts twin profiles in this import routine.