Offshore Ring Plate

Last updated April 28, 2017 by Steel Extensions

Software version: 
Not environment-specific

Offshore Ring Plate


Purpose and description
System Requirements
Installing the Offshore Ring Plate extension
Using the Offshore Ring Plate extension
Offshore Ring Plate properties
Additional information
Limitations on Split Plates
Trouble Shooting

Purpose and description

This plugincomponent that is developed using Tekla Open API

Plugin is a .dll file and loaded inside Tekla Structures process.

Plugins can be started from the applications and components catalog.

will create offshore ring plates and cap plate(1) part that represents a flat structure

(1) In some contexts, for example in analysis, the term plate object may be used to refer to plates.

(2) plate that represents a steel structure

(2) Plate is mainly used as a connection piece or as a floor plate.

connections which are needed at the connection of beam flanges and round pipe columns. The geometry of the ring plates is potentially quite complex and this tool will easily generate parts which are very cumbersome to create manually.

This tool focuses only on the creation of the ring plate. The connection between the web of the beams and the ring plate, or the web and the pipe are out of its scope. However, once the ring plate has been created, these details and connections are much easier to create using existing tools and custom components.

System requirements

Tekla Structures
Environments: Any

Installing the Offshore Ring Plate extension

The extension is now available in two formats; Tekla Structures version (and x86/64bit) specific *.msi installers that support Tekla versions up to and including 21.1 and from Tekla Structures 2016 a *.tsep (Tekla Structures extension package) format.

To install the *.msi based extensions to Tekla Structures 21.0 or earlier:

  1. Close Tekla Structures.
  2. Install the applicationpart of Tekla Structures functionality that is developed in order to extend the capability of Tekla Structures but that is not included in the Tekla Structures installation

    using the appropriate 32bit (x86) or 64bit installation package.

To install the *.tsep based extensions to Tekla Structures (available in Tekla Structures 2016) from Tekla Warehouseservice for collaboration and for storing and sharing Tekla Structures content

In Tekla Warehouse the content items are stored in collections. Tekla Warehouse includes the Tekla Warehouse Service and the Tekla Warehouse web site.

Tekla Warehouse is one of the Tekla Online services.


  1. Download the extension from Tekla Warehouse.
  2. According to which browser you are using, when the file has been downloaded either the Tekla Structures extension manager will open automatically or you may need to right click on the downloaded file and choose the 'open' option.
  3. The Tekla Structures extension manager dialog will be displayed and will show a list of installed Tekla Structures versions compatible with the extension. Choose the versions you wish to install to by selecting the check boxes next to each version's name, then click 'Import'. You may be asked to accept the License.
  4. The extensions will now be queued for installation to the selected versions. The installation will happen the next time that version is started.

To install a saved *.tsep extension package to additional Tekla Structures installations.

Having downloaded a *.tsep based extension, that file may be saved and installed on multiple Tekla Structures installations:
  1. To import from a running Tekla Structures:
    1. Open the Applications & Components menu and from its 'Access advanced features' button menu select 'Extension manager...' which will open the manager dialog.
    2. Click on the 'Import...' button and browse to the extension you wish to install.
    3. The chosen extension will be added to the import queue for the running version and installed when Tekla Structures is next restarted.
  2. To install from the file manager menu:
    1. browse to the saved file, right click on the file and select 'Open', the Tekla Structures extension manager dialog will be displayed.
    2. Choose the version(s) to install to and click on 'Import'.
    3. The chosen extension will be added to the import queue for the version(s) selected and installed when Tekla Structures is next restarted.

Applications and Components menu

From Tekla Structures version 21.1 the extension is accessed from the Applications & components menu. The installer creates a group called 'Offshore Ring Plate extension' in the root folder with an icon for the extension component. If you wish to customise the menu, the component may be added to any new or existing groups in the normal way. To remove the automatically created Offshore Ring Plate extension group it is necessary to locate the catalog filefile that defines catalog information used by Tekla Structures

Catalog files can have different file name extensions, for example, .bin, .db, or .inp.

installed as part of this extension and remove it (this will also remove the descriptions of the components so you will need to provide your own). That file is located in the Environments\common\extensions\OffshoreRingPlate folder and is called Note that renaming the .ac.xml part of the name will cause it to be ignored too.

Using the Offshore Ring Plate extension

To use the extension in Tekla Structures version 21.0 and earlier:

  1. Open the Component Catalogcatalog that contains all system components and custom components, and the macros and applications

    (Ctrl + F).
  2. Either use 'Search' or browse the 'Plugins' category to find the OffshoreRingPlate extension and click on the component's icon to start it.

To use the extension in Tekla Structures version 21.1 and later:

  1. Open the Applications & components menu (Ctrl + F).
  2. Browse to the Offshore Ring Plate extension group and open it, (or use the search featurepart of Tekla Structures functionality that is maintained and owned by Trimble Solutions and that is included in the Tekla Structures installation

    to locate it) then click on the component's icon to start it.


  1. Select a single round pipe column as the main (primary) part.
  2. Select up to ten H beams or plate beams as secondary parts.
  3. The plugin will attempt to generate a shaped contour platepart whose outline form the user defines by picking three or more points

    The user can define the shape of the contour plate parallel to the work plane. The profile in use defines the thickness. The corners of the contour plate can be chamfered.

    that connects the secondarys to the primary.

Setting Out

The plugin will use the first secondary beam as a datum from which to set the level of the Ring Plate. The plate's position relative to this may be modified using settings described later in this document.

Offshore Ring Plate Properties

The Picture Tab:

Parameter Default Description

Parameter Default Description
Cut Yes Yes / No option to cut a hole in the ring plate around the pipe.
Gap 0 Gap between the pipe and the ring plate when a hole is cut.
Radius R 1.5*radius of the main pipe The radius of the basic ring plate.
Split plate No Yes / No option to split the ring plate in two.
Angle A 45 The angle of the split line, measured counterclockwise from the axis pointing along Beam 1.
eT 0 The amount of extra material to add along the split seam (see below for details).
The weld tab length.
The weld tab width.
The rounding of the corner at the weld tab.
Plate alignment Top Top / Bottom option to control the alignment of the ring plate with the beams / flanges.
Vertical offset 0 Option to offset the ring plate from the alignment line.
T 30 The thickness of the ring plate.
Prefix (options) The profile prefix for the ring plate.
Material (options) The material of the ring plate.
Name RINGPLATE The name for the ring plate.
Plate Prefix (options) The prefix for the ring plate part mark.
Plate Start No. (options) The start number for the ring plate part mark.
Assembly Prefix (options) The prefix for the ring plate assembly mark.
Assembly Start No. (options) The start number for the ring plate assembly mark.
Finish (blank) The finish for the ring plate.
Class 99 The class for the ring plate.

Note: where the default value is shown above as (options) the values used taken as those set in the Tools > Options > Options > Components menu.

The Beams Tab:

The Beams tab consists of a gridmodeling aid that represents a three-dimensional complex of intersecting grid planes or intersecting grid planes and curved grid surfaces

The grid is defined by coordinates in 3D space. It is shown two-dimensionally on the view plane by dash-and-dot lines. A grid can be rectangular or radial.

It is possible to have more than one grid in a model. For example, a large-scale grid for the entire structure, and smaller grids for some detailed sections.

It is also possible to show grids and grid line labels in drawings, and to modify how they are shown in the drawings.

of up to ten rows in which to input and display properties related to each of the (up to ten) secondary beams/flanges. Use the'+' key to add rows to the bottom of the grid, highlight rows then click '-' to delete rows and use the '<' key to insert a row below the current row.
If properties are not entered for all beams, e.g. if there are four beams but only properties entered for beam 1 and 2, then the other beams will use the same properties as the last beam, beam 2. This means that for simple connections, the properties can be set for beam 1 and will be applied to all beams.


Parameter Default Description
L 2*pipe radius Length from the center of the main part to the edge of the flange along the axis of the beam.
E 0 The extension of the landing edge beyond the edge of the flange.
T 0 Taper length of the extension. If E is 0, T cannot be set or has no meaning if set. If T is 0, then the corner is square.
FL 0.5*pipe radius The rounding of the corner fillet between the left edge and the primary ring.
FR FL The rounding of the corner fillet between the right edge and the primary ring
Shape Fillet Option to select a Fillet, Straight or simple Rounded connection between the beam and the next beam.
R-Alt R An alternate radius or internal dimension for the connection between the current beam and the next beam.

The following example is intentionally complicated in order to illustrate how the variables and options are intended to work together. In the following example, the primary radius is set to 250, and no cut has been made in the plate (e.g. this is a cap plate).

Beam 1 to Beam 2 – An alternate radius of 300 has been given for the edge between these two beams.

Beam 2 to Beam 3 - The edge between beam 2 and 3 is specified to be straight. As no alternate radius is given, the straight edge is placed so that the minimum distance from the center to the edge is 250.

Because Beam 2 is slightly skewed, the straight edge will not be at exactly 45 degrees relative to the paper.

Beam 3 to Beam 4 – Nothing special here.

Beam 4 to Beam 1 – The fillets are both set to 150. The shape between is set to a simple round corner. Note however that because of the alignment and taper of the legs, even if the simple round corner were not specified, that is the only corner which would work in this case because the edges meet more than 250 away from the center.


5. Corner shape options and resulting geometry

Fillet corner: The shape of the ring plate at the connection of a flange is calculated / constructed as shown:

Round corner: In the diagram (below) it can be seen that it is not possible to create a Round corner between beams 1 and 2, so the logic will adopt a Fillet. However, between beams 2 and 3 a Round corner is possible, and the radius adopted would be that specified for beam 2 right.

Straight corner: If a Straight corner between two beams is selected, the construction is done similarly to a Fillet, but using a straight edge between the two outer radii. The straight edge is a tangent to the column circumference at radius R or Ralt if that is set.


Additional information

  • The plugin logic will attempt to generate the shape of corner selected by the user but in certain cases, such as for a single incoming beam, a Round or Straight corner geometry cannot not be generated so the plugin will automatically convert this setting to a Fillet style of corner.

  • Similarly, if the angle between two beams is too small for a Fillet style corner to be constructed it will revert to a Round corner.

  • If the Cut plate option has been set to Yes, and the weld tab dimensions eX and eY are both greater than 0, the plugin will attempt to create weld tabs in the specified location set by Angle A. Sometimes this may not be possible. For example it is not possible to fit a tab within the two outer radii of a Fillet corner, only in the single inner radius. Should tabs be specified but not generated, the plugin's cone symbol will be set to red. By changing the value of angle A and modifying the connection, it should be possible to try a variety of locations until a suitable position is found.

  • The Ring Plate is constructed as a polygon by creating an internal contour plate that is defined by the locations of the beams and which circumscribes the column in a series of facets. If a Split plate is specified, there will be two plates with start and end points that may be in any location as defined by the cut angle. Surrounding that inner plate are a series of additional plates, between each pair of beams. These may be shaped according to the user settings (Fillet, Round, or Straight). If a split plate is specified, there will be two plates broken along the cutting linestraight line that is defined by picking two points and used for shaping the part or a rebar set

    . In some circumstances (such as if the cut goes through a chamfer) it will not be possible to make a valid pair of plates and either a single or no plates will be created. The outer plates are combined with the inner plates as 'Added Material'.

  • If the Cut option is set to Yes, then a part cutcut that is defined by a cutting part

    is used to remove the appropriate material from the inner contour plate.

Limitations on Split Plates

  • Splitting of plates can only be successful if both ends of the cut line fall in the zone between the outer fillets (as defined by FL and FR in the Beams tab).

  • Weld Tabs and any associated fillets (as defined by eR) must also fall inside the same points.

Trouble Shooting

  • Occasionally the input data may define a plate that it is not possible to model correctly. This is usually obvious as the plate becomes transparent.

  • If the reason for the problem is unclear it is suggested that the input data is simplified until the plate models correctly.

  • Suggestions for troubleshooting invalid plates:

    • Turn off any welding tabs if you suspect that their extents may be encroaching into corner chamfers.

    • Turn off the Split plate option completely or try changing the cut angle to ensure that it too doesn't encroach into any corner chamfers.

    • Try increasing the plate outer radius or change Ralt for the affected beam corner sector.

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