v2.3.1

24 Nov 2021 | Maintenance Release
Build 26620

MAINTENANCE RELEASE

Enhancements

• Changed the tab hover tooltip in the Scenario Manager to read "Delete scenario" [ref:5662]
• Updated the solver kernel to MOSEK 9.3, which includes a fix for a matrix transposition bug identified by LimitState [ref:5663]
• Enhanced the analysis output stream to help users identify situations where the solution obtained is to be disregarded [ref:5670]
• Added link to limitstate.com to Trial license dialog [ref:5671]

Bugfixes

• Fixed a bug that could cause an error message referring to "upper line has <2 data-preserve-html-node="true" points" [ref:5549]
• Fixed a bug that meant internal boundaries could be incorrectly labelled as external when a geometry is read in from DXF [ref:5551]
• Fixed a rare bug that could cause line loading to be mis-calculated when lying above a geometry that includes a concave region intruding from the left side [ref:5656]
• Fixed bogus error message "Mismatch of solid edge angles", which could arise when a check did not consider whether an angle was positive or negative 180 degrees [ref:5660]
• Fixed a bug that could cause line load position changes to be applied across all load cases in a multi-scenario problem [ref:5661]

v2.2.2

5 July 2021 | Bugfix Release
Build 26321

CRITICAL BUGFIX RELEASE

Critical Bugfix

• Fixed a bug that caused lift-off properties to be invisibly retained when switching boundary support conditions from "simply-supported" to "free". In cases where lift-off was set to "true", this could cause the free boundary to behave erroneously. Solutions obtained from files created and/or saved with a previous version will now be correct [ref: 5653]

v2.2.1

27 May 2021 | Bugfix Release
Build 26217

CRITICAL BUGFIX RELEASE

Critical Bugfix

• Fixed a bug that meant modifications to the magnitude of existing loads in the Loads Database were not pushed to all Load Cases in the Load Case Manager. This could cause erroneous results to be obtained. The issue persists over file save and, therefore, users with older versions are advised to upgrade to this release as soon as possible [ref: 5618]

Enhancements

• Compatibility with Apple M1 chip (under Rosetta 2) now tested [ref:5591]

Other Bugfixes

• Fixed a bug that prevented images of the failure mechanism being generated (e.g. for the report) when using the software with MacOS [ref:5614]
• Updates solver to MOSEK v9.2. This fixes a compatibility issue that was present in older versions of the software when run on systems with newer AMD processors [ref:5612]

v2.1.e

3 Feb 2020 | Maintenance Release
Build 24265

MAINTENANCE RELEASE

• Academic licenses are now accessed from new server address in advance of shutdown of legacy server in Q3 2020 [ref:5407]

v2.1.d

10 Sep 2019 | Maintenance Release
Build 23785

MAINTENANCE RELEASE

Bugfixes

• Fixed a bug that prevented v2.1.c files from being opened in previous releases. Version 2.1.d files are backwards compatible throughout all v2.x releases [ref:5341]

• Fixed a bug that caused the License Dialog to be incorrectly titled DXF Import [ref:5350]

• Fixed a bug that meant that a project could not be saved following completion of a Wizard if the licensing was changed to "Academic" from some other license type [ref:5351]

v2.1.c

13 Aug 2019 | Maintenance Release
Build 23657

MAINTENANCE RELEASE

Enhancements

• Set the styling of construction lines created on import of a DXF geometry to match that of lines created manually (i.e. grey, dotted lines) [ref:5305]

Critical Bugfix

• Fixed a critical bug which caused the moment of resistance to be calculated incorrectly in the rare circumstance of an orthotopically reinforced slab with orthogonally inclined reinforcement and moments of resistance specified at angles of exactly 45, 135, 225 or 315 degrees [ref:3508]

Other Bugfixes

• Fixed the ability to print a report directly from the report dialog [ref:5306]
• Fixed a bug that caused DXF files to import incorrectly (or sometimes crash the software) [ref:5254]

v2.1.b

19 Mar 2019 | Major Release
Build 23016

MAJOR RELEASE

Enhancements

• Added option in the installer to use software rendering. Reinstall with this option selected if graphical or startup issues are experienced. These occasionally occur due to graphics driver compatibility problems [ref:5210]
• Improved formatting of diagrams in help files [ref:5321]

Minor Changes

• Added forward compatibility with previous 2.x versions [ref:5229]

v2.1.a

21 Dec 2018 | Major Release
Build 22568

MAJOR RELEASE

Enhancements

• Very high resolution (e.g. 4K) screens are now supported on Windows. The size of text on such screens is optimized for readability [ref:5115]

• Changed structural definition drag cursor to make it easier to drop on boundaries [ref:4944]

Bugfixes

• Fixed localization error that broke calculator when using commas instead of decimal points [ref:4983]

• Fixed error that meant a load type changed in the property editor wasn't changed in the load manager [ref:5069]

• Fixed a bug that caused occasional failures due to numerical tolerance issues in geometrical calculations [ref:5133]

v2.0.b

5 Apr 2016 | Major Release
Build 20281

MAJOR RELEASE

New Functionality

• Added a number of new support types and behaviours. The software now allows the user to choose from the following options [ref:4691] [ref:4766]: External Boundaries
  • Free
  • Symmetry
  • Fixed
  • Simple
  • Partially fixed

Internal Boundaries

• None
• Knife-edge

Lift-Off

• For boundaries with Simple or Knife-Edge support types, the option to allow lift-off of the slab has also been added. This allows the potential for uplift of the slab to be modelled where appropriate.
  • Added new functionality to allow the problem to be re-scaled during the solution phase, thereby increasing solver reliability and robustness [ref:3943]
  • Added a new 'Rigid' structural definition type [ref:4772]

Enhancements

• Modifications to the way in which self-weight is treated [ref:4762]:
  • Problems generated using a wizard now consider self-weight loading by default.
  • A diagnostic warning is issued for problems containing slab definitions with non-zero self-weight properties, but no load cases with self-weight loading.
  • A diagnostic 'information' message is issued for problems with self-weight loading and containing only the default 'Unit MP Weightless' definition.
  • A diagnostic warning is issued for problems containing load cases with self-weight loading, but not utilizing slab definitions with non-zero self-weight (other than that mentioned above).
  • Updated example files to prevent warning above warning messages being displayed [ref:4786]
• Added a new diagnostic message that warns the user if a disproportionately small number of nodes (<20% data-preserve-html-node="true" of the overall total) exist within solids [ref:4831]
• Enhanced "DXF Import" dialog to add information relating to the units used and the bounding limits of the file being imported. Where the file is unitless, dimensions will be assumed to be the same as those set in the software (e.g. metres or feet). Additionally, warn the user if the geometry appears to be too large, too small or positioned a long distance from the origin [ref:4767]
• Improved the way in which DXF files are handled [ref:4839]:
  • Prevent zero thickness solids from being created (where two boundaries lie on top of each other in a DXF).
  • Added a check that attempts to identify isolated islands in DXF files and alert the user so that they are able to fix the issue.
  • Fixed a bug when removing DXF entities from unwanted layers, which could cause the software to crash.
• No longer do filter stage by default at the end of an analysis, reducing solution time and improving solver reliability. In the filter stage nodes were added at yield-line crossover points, and one or more analyses were subsequently performed, in some cases leading to a very slightly improved solution (thus some existing files may report a very slightly higher adequacy factor and/or a marginally different failure pattern as a result of this change) [ref:4830]
• Allow creation of new vertices at intersection between boundaries and construction lines [ref:4860]
• Updated 'Irregular office block floor' example file to have more accurate geometry and material properties [ref:4744]
• Upgrade Mosek solver and add Win 10 support [ref:4688] [ref:4881]
• Updated Product Description [ref:4879]

GUI Updates

• Resize structural definitions explorer to use larger grid [ref:4693]
• Rename 'Slab Definition' to 'Structural Definition' throughout [ref:4689]
• Upgrade to Qt 5.4.2, which brings improvements to GUI appearace including improved rendering and a cleaner interface [ref:4688]
• Change help icon and about dialog [ref:4783]
• Improve locale settings e.g. so that commas and/or points are treated as decimal places according to the settings of the host machine [ref:4814]

Bugfixes

• Fixed a bug that could prevent new solids from being created within concave sections of an existing solid [ref:4856]
• Fixed a bug that prevented solids within another solid (i.e. 'islands') from being split by a user-defined boundary [ref:4859]
• Fixed a bug that could cause a crash by allowing the side length of a wizard generated geometry to be zero. A minimum length of 0.01 units is now enforced [ref:4858]
• Fixed a bug that could cause a crash when trying to merge two boundaries that initially shared a single vertex [ref:4862]
• Fixed a bug that caused images to be exported at a different size to that specified in the software preferences [ref:4863]
• Default slab definition thickness modified to become a more realistic value (0.25m) [ref:4791]
• Fixed a numerical issue involving geometry points with x coordinates very close (but not equal to) zero that caused the solver to show "Error: 01007: Out of bounds x-coordinate..." [ref:4761]
• Fixed a bug that could cause 'floating solids' to appear when deforming some complex failure mechanisms [ref:4600]
• Fixed a number of Imperial unit issues (primarily where they were displayed as the Metric equivalents) [ref:4598][ref:4679]
• Fixed a bug that could cause a crash when switching between loads and geometry tab in the 'new slab wizard' [ref:4634]
• Fixed a bug that allowed both radio buttons to be disabled in the post-solve animation settings [ref:4622]
• Fixed a bug that prevented user defined camera position from being used [ref:4773]
• Fix snap settings to account for user preferences [ref:4860]
• Fixed 'ln' function in the calculator [ref:4723]
• Fixed a bug that prevented files from being saved when creating new ones. Also changed default behaviour to request new file name from user when saving for the first time [ref:4724]
• Fixed a bug that could cause file corruption when pressing Cancel in the Project Details dialog (ultimately causing the software to crash) [ref:4872]
• Fixed a bug that could cause a crash if a Wizard was cancelled after specifying loads [ref:4875]
• Allow partial safety factor on material to be exported and imported along with other values in the CSV file [ref:4870]

v1.0.d

17 Mar 2015 | Maintenance Release
Build 18482

MAINTENANCE RELEASE

Enhancements

• Upgrade the installation software and check for x86 (32bit) operating systems when attempting to run the 64bit installer [ref 4572]

Bug Fixes

• Warn the user (and offer to fix) when a solid object is loaded twice by a pressure load with exactly the same specifications (Load, Action Type, Adequacy and Position) [ref 4586]
• Add a new diagnostic check for duplicated self-weight or pressure loads [ref 4588]
• Improved the logic when merging solid zones or boundaries with different properties. Previousy the allocation of nodal spacing, slab definition and pressure loading was done on an ad-hoc basis. The software now assigns the new zone the properties from one of the merged objects and alerts the user as to which has been used [ref 4582] [ref 4586]
• Fix load case spin box so that it does not display "0 of 0" when the load case manager is shown then cancelled [ref 4584]

Note that from version 1.0d communications with the update server have been set to allow automatic updating to newer releases (for those not behind a restrictive firewall)

v1.0.c

10 Mar 2015 | Maintenance Release
Build 18406

MAINTENANCE RELEASE

Enhancements

• Enhance solid selection when applying pressure loads [ref:4558]
• Synchronize tabs on viewer and load case manager during the editing of load cases [ref:4563]
• Prevent flickering in the viewer window during a solve [ref:4561]
• Fix internal boundary colors when using slab with hole wizard [ref:4569]
• Enhancements and corrections to manual [ref:4545] [ref:4536] [ref:4546] [ref:4547] [ref:4548]
• Add context help to Load Case Manager dialog [ref:4552]
• Prevent the grid from being shown with thicker lines when opening a file [ref:4463]
• Use consistent terminology for plastic moments of resistance in the report [ref:4554]

Bug Fixes

• Prevent exception when clicking on the pressure load icon [ref:4557]
• Change analysis icon in the New Project wizard [ref:4562]
• Remove Torsional Rotation and Shear Displacement 'Yield-line' properties from Property Editor (as they are not currently calculated) [ref:4568]
• Set the SLAB subfolder in 'Documents' to be 'LimitState SLAB files', not 'slab files' [ref:4556]
• Remove Property Editor references to multiple-definition Boundaries, as these are not achievable in the software [ref:4567]

v1.0.b

10 Feb 2015 | Major Release
Build 18351

MAJOR RELEASE

New Functionality

• Allow skew angle for reinforcement [ref:4266] [ref:4527]
• Enable imperial units [ref:4362]
• Add new wizard to model a rectangular slab with hole [ref:4454]

Enhancements

• Enhance rendering quality and performance [ref:4316]
• Improve the quality of the GIF and AVI animations [ref:4452]
• Enhance released example files [ref:4419]
• Make default grid spacing 1m with 10 subdivisions [ref:4459]

GUI

• Move Loads toolbar to the top [ref:4470]
• Reduce the size and spacing of boundary hatching to aid user understanding of boundary fixity [ref:4483]
• Hide loads before solve [ref:4422]
• Make it easier to select objects in the viewer [ref:4381]
• Removed 'Support Type' information from the 'Vertices' and 'Solids' explorer windows. (The ability to apply supports to these features is not currently available.) [ref:4479] [ref:4529]
• When the Rotate toolbar button is selected, ensure that the overlay (circle with draggable handles) is always visible and not obscured by the model [ref:4482]
• Enhance loads visualization to make it easier to use [ref:4486]
• Reduce default slab definitions explorer width [ref:4469]
• Apply spot light correctly on all generated frames in the animation [ref:4492]
• Fix line load color [ref:4411]
• Change default slab definition color [ref:4533]

Solver

• Fix numerical issue with problems using skewed columns [ref:4480]
• Upgrade Mosek solver to 7.1 [ref:4498]
• Changed material partial factors to be divisors [ref:4512]
• Ensure that the load case name is displayed in the output window during a solve [ref:4415]
• Fix numerical issue when a load is applied on a support [ref:4466]
• Remove incorrect partial factor sets [ref:4495]

Documentation and Report

• Major changes to manual and other documents [ref:4505]
• Added reference in manual and report output to journal paper detailing the theory behind yield-line analysis using DLO [ref:4387]
• Modify the symbols used for the material definitions in the property editor and the report [ref:4467]
• Ensure that the 'Details...' hyperlink in the Units tab takes you to the appropriate manual entry [ref:4418]
• Enhance slab definitions in the report [ref:4376]
• Reword report summary [ref:4535]

Usability

• Group pressure loads of the same type in the Load Cases Manager [ref:4340]
• Show pressure loads as a red triangle in the top right corner of the solid (with no offset) [ref:4382]
• Remove unneeded attributes from property editor [ref:4523]
• Rename load magnitude attributes in property editor [ref:4532]
• Fix construction line usability issue [ref:4471]
• Add unit MP Concrete slab definition [ref:4487]
• Prevent snapping of point and line loads to the grid when SNAP is disabled [ref:4488]
• Add diagnostic message for solids with no slab definition [ref:4534]
• Update product description [ref:4386]

Bug Fixes

• Fix trial license [ref:4379]
• Fix academic license [ref:4394]
• Fix descriptions in property editor [ref:4468]
• Fix issue where the deformations used to illustrate the failure mechanism are calculated incorrectly in certain circumstances [ref:4474]
• Prevent page breaks inside tables in the RTF report. Make RTF the default output format [ref:4406]
• Ensure that the 'locked' attribute for the slab definitions is saved to file [ref:4460]
• Prevent crash when unlock is pressed whilst diagrams are being shown [ref:4461]
• Ensure that the slab Load Case Manager dialog displays the correct title [ref:4462]
• Update the status of the toggle buttons in the 'Show' toolbar after opening a file [ref:4369]
• Show the right selection type status on the main form [ref:4370]
• Show the correct title on the Edit Slab Definitions Dialog [ref:4524]
• Fix a bug when a dxf file is imported, and allow negative offset for loads in the Load Case Manager [ref:4501]
• Disallow adding multiple slab definitions to the same solid [ref:4528] [ref:4541]
• Avoid having multiple slab definitions when drawing solids using the viewer, and create new solids on the viewer with no default slab definition [ref:4432]
• Fix undo/redo when loads are added/edited [ref:4420]
• Prevent crash when using the Load Case Manager in a new project that was created without using one of the wizards [ref:4476]
• Fix boundary external/internal status in newly created files [ref:4424]
• Fix a bug when deleting first load case [ref:4538]
• Fix spotlight when changing preferences [ref:4543]
• Avoid hiding solids in multiple load case projects when one load case is deformed [ref:4410]

v1.0.a

11 Dec 2014 | Beta Release

BETA RELEASE

LimitState:SLAB is a software program designed to rapidly evaluate the load carrying capacity of existing and proposed concrete slab structures using the yield line analysis method.

Features

POWER

• Rapidly determine the capacity of concrete buildings and bridge decks without the need to pre-guess the failure mechanism.

ECONOMY

• Uses plastic limit analysis methods, which promotes more efficient solutions than alternative techniques based on elastic material properties.

FLEXIBILITY

• Define any concrete slab geometry by drawing on screen, using a built-in wizard or by importing the layout from CAD.

EASE OF USE

• An intuitive GUI means learning to use the software is a straightforward process.

CLARITY

• Presents a clearly defined failure mecha nism and numerical factor on the applied loading. Animations are used to enhance user understanding of the collapse mechanism.