Release notes: Tekla Structural Designer 2020 SP4

Tekla Structural Designer
Tekla Structural Designer
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Release notes: Tekla Structural Designer 2020 SP4

This release will upgrade your Tekla Structural Designer installation to version number and should be installed to ensure optimum function of the program. It includes a number of enhancements and issue resolutions as detailed below.

If you are upgrading from a version earlier than release 2020 SP3 (version released July 2020), you can find details of requirements, enhancements and fixes for all previous releases in Tekla User Assistance (TUA) and Tekla Downloads via the links below:

Licensing & Installation



  • This service pack requires Tekla Structural Designer 2020 first release (version or later to be installed and will replace your current version.
  • Integration

  • Previous Versions and file compatibility - Files from all previous versions can be opened in this release however note that, once saved, they may not open in an older version. If you wish to retain this option we therefore recommend using the File > Save As… option to save a new version of the file and retain the original.

  • Databases - Some Databases are updated in this release. When this release is first run, your Databases will now automatically be updated and it is no longer necessary to do this manually via Home > Materials. See Other Enhancements & Fixes, in the General & Modeling section below for more on this.

Issues with Associated Bulletins

  • [TSD-7035] - Shear only walls - these were introduced in the 2020 first release (version March 2020). However, the initial modeling formulation for these had the limitation of failing to report the vertical ‘push-pull’ effects at the ends of the panel that would be expected to be present to resist overturning. Due to the potential for mis-use and mis-understanding this caused, the option to use shear only walls was accordingly removed in the 2020 SP2 release (version May 2020). For more information please see Product Bulletin PBTSD-2005-2.

  • [TSD-2529] - Wind Wizard - Finland (Eurocode) Head Code - for Terrain category 0 (Sea), the calculated peak velocity pressure qp was incorrect and too low, thus producing wind loads which were not conservative. Loads for other Terrain categories were not affected. For more information please see Product Bulletin PBTSD-2007-1.

    • This issue is fixed in this release. Note that for existing models with this circumstance, the Wind Wizard must be run again to correct the peak velocity pressure qp value.

General & Modeling


Enhancements and Fixes

  • A number of additional fixes which are not detailed explicitly here are also made to improve general performance and stability. An example of this is given directly below:

    • [TSD-5746] - Composite Beams and Concrete Beams - significant improvements are made to the calculation process for both the effective width of composite beams (both floor and natural frequency) and flange widths of concrete beams. This improves the performance particularly for very large models with 1000’s of beam spans:

      • Composite beams - this primarily impacts the time taken to populate the Properties Window for a selection of beams - a selection of many beams in larger models which previously could occupy a few minutes now takes a matter of seconds.

      • Flanged concrete beams - this impacts the time taken for analysis and design and can result in an improvement in performance (in terms of reduced overall analysis and design time) of 2-3 times or more.

  • [TSD-4943] - Sub Structures - further to recent enhancements to the creation and management of Sub Structures, additional enhancements have been made in this release so that members created/edited/copied/moved while working in a Sub Structure view are retained in the Sub Structure.

  • [TSD-4890] - Isolated Foundations - when the base level of an isolated foundation is moved, the current foundation along with support moves to the new level where in previous releases it would be deleted. This applies to foundations of; columns, walls and portal frame columns.

  • [TSD-3672, 7377] - Steel Beams - Plated Fabrication - different types of plated beams can be modeled, including those used in proprietary systems (such as Westok and Fabsec]. Previously, whenever there was a change in plated beam fabrication, the default section size would be applied. This behavior is improved in this release to retain the dimensions of the beam section in this circumstance thus enabling a more convenient workflow.

    • If the corresponding section does not exist in the Steel section database, it is created on the fly (in the model) and can be added to the local database at the engineer’s discretion by reviewing the new sections in the model (via Home > Materials > Model).

    • Note that the same section size - namely the one from the first span - will be assigned to all spans of multi-span plated beams when changing fabrication.

  • [TSD-6831, 6834] - FABSEC Fabrication - Openings - elongated openings can now be defined in beams set to the FABSEC fabrication option, as illustrated below. Elongated openings are also imported/ exported correctly when conducting integration with the FBEAM program (for more on this see Export to and import from FBEAM).

    • The Web opening dialog features automated validation checks that the elongated opening satisfies recommended dimension limits, as for existing opening shapes. As part of this enhancement, for all openings a warning triangle icon is now displayed rather than an error icon for dimensions that exceed recommended limits but can still be OK’d (at the engineer's discretion).

    • Note that, prior to this release, such openings were handled using a UDA - this method is now removed and the UDA no longer used. Any existing models containing equivalent elongated openings can be updated by re-importing the appropriate FBeam .xml file.

    • Elongated openings are not valid for other fabrication types, however they will be retained if this is changed from FABSEC. Hence new validation is added to check for this circumstance and a validation error will be reported for it as shown below.

  • [TSD-5578] - Databases - as noted in the Installation section above, this release introduces automatic updating of your local Databases, so it is no longer necessary to do this manually. This process works as follows:

    • Providing all databases can be updated automatically without user intervention, when this release is first run then the updates are applied and a message is displayed stating "updating to latest database versions" as shown below. On successful completion this closes and the program will open.

  • [TSD-7194] - Timber Columns - Splices can now be introduced into timber column stacks in the same manner as for steel columns (via the stack properties) to enable having different section sizes above/ below the splice.

  • Section Properties:
    • [TSD-5618] - Timber - the major and minor Shear Area values for rectangular Timber sections are revised to (5/6)*Ag from the previous 0.5xAg (where Ag = Gross section area). This change aligns the shear area value with that used by Tedds. Note the following:

      • The shear area affects only the component of deflection from analysis due to shear deformation and is not used elsewhere by the program. Moreover the proportion of the gross area used to calculate the shear area - commonly termed the “form factor” - is essentially an estimate and different references on elastic theory may differ on the value for various section shapes. The factor of 5/6 is commonly accepted for rectangular sections and elastic behavior.

      • Since shear deflections are inversely proportional to the shear area and - for normally proportioned beams - usually account for a smaller proportion of overall displacement, the previous smaller 0.5xAg value would have produced a generally minor overestimate of the shear component of deflections only, hence this update will produce a reduction in deflections of a similar order.

      • To update the shear area values for existing models, go to Home > Materials > Model > Sections then select the timber section(s) listed and select “Update from Database”.

    • [TSD-5427] - Steel - the names of Continental UB “350x175” sections (Nominal depth D = 350 mm and nominal breadth B = 175), have been corrected from the previous “300x175” name according to the manufacturer's catalog. This change is relevant for the regions of Singapore and Malaysia. Note that the issue relates to the name only - the section values were correct per the manufacturer's catalog for “350x175” sections.

  • [TSD-3992] - Review View - Slab Reinforcement - the legend for Show/Alter State > Slab Reinforcement is now expanded with multiple page options in the same manner as other options - such as Section/ Material Grade - have been in previous releases. This removes the previous limit of 9 reinforcement variations and enables the graphical review and editing of any number of these. When the number of variations exceeds 9, the next legend page right arrow > is enabled as shown in the picture below - you can then move forward/ backward between legend pages to review all the reinforcement variations.



Enhancements and Fixes

  • Trimble Connect - Integration with Trimble Connect is enhanced with the following new options:

    • Drawings - Upload of any DXF drawing to a linked Trimble Connect Project. This option is listed in the DXF Export Preferences dialog as shown below.

    • Reports - Upload a PDF of any Report to a linked Trimble Connect Project via the new “PDF Upload” button in the Trimble Connect group of the Report Ribbon.

      • Both this and the DXF Export Preferences dialog include an option to open the new Trimble Connect File browser to allow the selection of the target project folder for created Drawing/ Report (see picture below).

      • Defaults for the default Target folder in the Trimble Connect project, and whether to keep a local copy of the report, can also be set via the “Upload Settings’ button.

    • Model Links - Uploaded Member Drawings/ Reports can also optionally be linked to their specific member in the uploaded IFC model, as shown in the pictures below. They can then be conveniently accessed directly from the IFC model attachments in Trimble Connect.

Open API

This release includes further enhancements to the Tekla Structural Designer Open API. For how to get started with the API, see the Tekla Developer Center. New additions to the API enable interrogation by an external application / process of the following objects and items:
  • Construction points & point groups

  • Planes (Levels / Frames / Slopes)

  • Slab items / slabs / slab openings / decks / slab patches

    • For slabs: Reinforcement, decomposition types, diaphragm options, mesh types

  • Roofs

  • Structural walls

  • Wind walls

  • Piles


  • Load Combinations - US Head Code:

    • [TSD-3294] - Seismic Combinations - In a similar manner to Gravity and other Lateral combinations, Notional Loads (NL) can now be included in seismic combinations. Addition of NL’s to seismic combinations is a manual process at the engineer’s discretion via the combinations dialogue - there is no automatic generation option in the Combination Generator.

      • The notional load value is calculated in all cases from the combination’s constituent "gravity" load cases - i.e., Self weight, Slab Dry, Dead, Live, Live (Other), Roof Live, Snow.

    • [TSD-4018] - Combinations Generator - the LRFD 1.4D combination is now enabled by default in the Load Combination Generator.

  • [TSD-7668] - Wind Loading - US Head Code - the Wind Loadcases dialog "Auto" command now correctly enables the "Roof Loads" option for the “±X’±Y’” cases when the Roof Cp checkbox is selected in load case generator, so all Wind loadcases now have Roof Loads enabled by default.

  • [TSD-4678] - Consequence/ Reliability Class - the setting for "Consequence Class" for Finland (Eurocode NA) and "Reliability Class" for Sweden (Eurocode NA) has been moved from the Structure Tree Properties to Settings (Global and Model) > Loading > General as shown below.

    • Note that if the class is changed, existing combinations are deleted and must be re-created as some dead load combination factors are dependent upon the class.

  • [TSD-7574] - Notional Loads, Equivalent Horizontal Forces (NL, NHL, EHF) - NL’s for previously analysed loadcases from which all loading had subsequently been removed were not updated to reflect this, leading to higher than required NL’s being considered. We expect this would be an extremely rare occurrence, however it has been encountered and is addressed in this release. The issue no longer occurs for new models. For existing models which you suspect may have this issue you should:

    • Review the applied notional forces and check they appear reasonable. If required the stored results can be cleared and hence NL’s updated by doing one of the following:

      • Use the Save model only command - will remove all stored analysis results and update the NL’s when you next analyze/ design.

      • Edit objects in the model such as the geometry of a member or it's supporting conditions - will set results to out of date so NL’s are updated when you next analyze/ design.

      • Use the Ctrl+right-click context menu from the Structure tree heading and select the “Clear solver results” option.

Analysis & Results


Enhancements and Fixes

  • [TSD-6770] - 3D only (Static) - a new analysis option “3D only (Static)” is added to the Analyze Ribbon as shown below. As the tooltip for this details - this performs the same analyses as “Analyse All (Static)” but excluding the chase-down analyses. It is thus a more rapid form of overall analysis which can be used to obtain/ update the results for all processes that use the 3D Building Analysis results, such as sway/ drift* checks and steel design.

    • *Seismic drift check results are not updated by this analysis when the RSA method is selected for Seismic - as in previous releases, RSA Design must be run to update these.


General Design Enhancements and Fixes

  • [TSD-4551] - Foundation Design - Isolated Pad Bases - Sliding Check- a new option is added allowing the engineer to control whether the passive resistance of the soil is included in the check of Sliding Resistance. In previous releases, the soil passive resistance was always included for all Head Codes except the Eurocode (all country NA’s) which always omitted it. As shown in the picture below, the new control is a check box in Design Settings > Concrete > Isolated Foundations > General Parameters > “Consider passive resistance of soil…”
    • To match previous behaviour, the setting defaults to on for all Head Codes except the Eurocode (all country NA’s).

    • In addition to the new control for all Head Codes, the soil passive resistance is also included in the sliding checks for the Eurocode Head Code (all country NA’s) when the new setting is enabled (default off).

  • [TSD-7527] - Design Summary Table - of particular use during the Design Review stage, you can now double-click a row of the Review Data > Design Summary table to select the associated entity in the Structure 3D view. This functions for all entities - beams, columns, walls, slabs etc - and materials which have a Design Summary table, including those for Timber Members introduced as part of the Timber design using Tekla Tedds feature detailed above and illustrated below.

    • As shown, you can arrange the table and Structure 3D view windows so they are both visible to assist with this process (the active view will automatically switch to the Structure 3D view after double-clicking the table row if this is not the case).

    • On double-clicking, the view automatically zooms/ pans to the location of the associated entity which is both selected and indicated with an arrow. Simultaneously the Properties Window is also populated with those of the entity.

    • This feature works particularly well in conjunction with Ghost Unselected On, making the selected entity exceptionally clear as illustrated.

  • [TSD-6674] - Concrete Design - Beams - All Head Codes - the design shear identification process has been enhanced such that the design shear force can originate from anywhere within the respective design region. In effect this increases the scope of the design to ensure that the maximum shear force in the region is considered for beams under special and less usual loading conditions such as forces applied within a distance ‘d’ of the support. Also included are minor adjustments and clarifications to the reported check results to make the origin of the design shear more transparent.

  • [TSD-7607] - Member Design - this issue relates only to release 2020 SP3 in which it was introduced and design/ check of individual members using the right-click context menu. In the 2020 SP3 release, a change was introduced which cleared analysis results on members which were changed by a direct edit - e.g. of their section size. This removed the workflow available in previous versions of investigating alternative member sizes using analysis results which could be out of date, but still considered useful. The change has been reversed in this release enabling this workflow once more.

  • [TSD-7223] - Composite Beams - Effective Width - in the unusual circumstances of an alignment offset being applied to composite beams such that the top of the beam was dropped below the bottom of the slab creating a gap - as illustrated in the picture below - the detection of adjacent beams in the automatic effective width calculation was impacted. This could result in the automatically calculated effective width (which can be reviewed/ edited by the engineer at their discretion) not being correctly limited by the beam spacing. Although we consider this to be an unlikely circumstance, it has been encountered and is addressed in this release. Such offsets (which are not structurally significant as noted in the properties dialog) are now correctly ignored by adjacent beam detection and the effective width limited by the beam spacing, where this governs.

    • Note that existing models with this circumstance will be flagged/ corrected by validation in this release depending on the setting Design > Settings > Composite Beams > “Update effective width prior to design check”:

      • When Off - affected beams will be flagged with a validation warning.

      • When On - the effective width of affected beams will automatically be corrected by validation and check/design.

Eurocode Design Enhancements and Fixes

  • [TSD-4551] - Foundation Design - Isolated Pad Bases - Passive Resistance - as noted above, the soil passive resistance can now be included in the sliding checks for the Eurocode Head Code (all country NA’s) by enabling the new setting for this; Design Settings > Concrete > Isolated Foundations > General Parameters > “Consider passive resistance of soil…”.

    • This new option also enables the “Ignorable percentage of passive pressure” value for pinned bases, which simplifies the design for small values of shear values which would commonly be ignored. Previously, this was only available for Head Codes which considered the soil passive pressure (always).

      • The % value default is 1.00 - set the value to zero to consider all forces no matter how small.

  • [TSD-6738] - Precast Design (using Tekla Tedds) - Columns - the Tedds Precast column design (EN1992) calculation was recently enhanced (in the Tedds Engineering April 2020 Update) with a basic shear check. The link with Tekla Tedds for precast concrete design is accordingly enhanced in this release to populate the calculation with shear force values from the Structural Designer model.

US Design Enhancements and Fixes

  • [TSD-5994, 7579] - Steel Design - Braces - Design is now carried out for steel braces with Rod section type for all years of AISC 360 (ASD and LRFD). The design is only carried out for axial tension, since rod sections are commonly only used for tension-only bracing and ties. Compression is beyond scope - a design details note is issued stating this and that the section is assumed slender and additional hand calculations are required.

    • A new Order list for Rod sections is also added in this release.

Reports & Drawings


  • [TSD-5518] - on selecting Show Report, the report is now opened with the continuous display mode active (so the report can easily be scrolled through with the mouse wheel) and the Project Workspace Report Index is also automatically activated.


  • [TSD-7000] - Gable Posts - General Arrangement (GA) Drawing - Gable Posts (Steel, Timber & Cold Formed) are now included in GA drawings and in Scene Content > Plan View.


The number in brackets before an item denotes an internal reference number. This can be quoted to your local Support Department should further information on an item be required.

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