5. Bug fixes and improvements

INSTANT steel 2013 version includes all the improvements and bug fixes that were made up to INSTANT steel 2012 version (patch 2012.01 – 2012.02). In addition, the following changes have also been included:

A. Linear 2D & 3D

  • The following error message is corrected (error TOP2FS.exe) after the failure of solving free modes by selecting the automatic recalculation of the specified eigenmodes.
  • The calculation of the inertia on weak axis (Iy) for composite sections has been corrected, where the value “a” that corresponds to the distance between two standard sections was initially taken in cm and not in mm as shown in the corresponding dialog window where the user was editing the value. In order to correct for the existing composite sections their Iy value please perform the following steps:
  1. Open the “Composite Sections” dialog window form the “Sections window database”.
  2. Select a composite section from the catalog. This will result in the composite section mechanical characteristics data being automatically recalculated.
  3. Delete the initial composite section from the catalog. The previous selections will remain.
  4. Add new section with the current data.
  • The Iw value data was altered for CHS, SHS and RHS section categories so that the value is now set to zero (0) as suggest by SCI.
  • The It values were corrected for CHS SIDENOR database.
  • The capability of zoom-in was improved so that it now supports 30 steps.
  • The button “Units” has been added in the following dialog windows: “Materials manager”, “Section selection”, “Define distributed load”, “Define support”, “Connection definition”, “Accidental eccentricities”, “Structural eccentricities”. This enables the user to change the displayed value units just be pressing the “Units” button to one of the above specified dialog windows.
  • The Analysis procedure has been changed slightly. By selecting Options > Expert user the “Analysis procedure” will enable the user to make more specific selections such as: Include work of shear, take into account eccentricities and so on. Otherwise, the default options for the “Analysis” will be used.


  • In the “Analysis files generation” dialog window, which is available only when the “Expert user” selection is valid, new options for activating nodal masses in separate global system directions have been added.


The above selections are only activated when in the “Free vibration” dialog window the option Masses > On nodes only is selected.


  • The capability of automatically producing 2D views from a model topology has been added. In the “Working planes” dialog window that is initiated by selecting the instant-wiki-05-04 icon, the button “Automatic” has been added. If the user press the “Automatic” button then the software scans the model and generates 2D working planes wherever at least a beam is found in a plane.


B. Results

  • The error in reading results from previous INSTANT steel versions prior to INSTANT steel 2012 version has been corrected.
  • If the selection “Expert user” is not active, in the “Spectral data – Modes” window, the “Residual mode analysis” and “Correction Mtot/SMi when SMi is <90%” extra options are not shown. In the latter case, the user can only select whether to include “Residual mode analysis” and “Correction Mtot/SMi when SMi is <90%” or not.

C. Member design

  • In the “Members” tab the members list now supports multiple selections for member deletion.
  • An error was corrected that could have occurred in a project where there were user defined sections that were no longer available in the section database. Now, a warning message is produced and the afflicted member is not enabled in the “Analysis” window.

D. Connections design

  • The value for kj coefficient has been corrected to 1.5 from 1.0 for base plate connections according to EC3 regulation, as it was mentioned in the assumptions for the specific connection.
  • Fixed a problem in the haunch data entry verifications where the program would not verify that the user had entered all haunch data and could run the analysis with incomplete data resulting in erroneous ratios. Warnings have now been added for any missing data.