Design Model

• Added the ability to arbitrarily change the contour of single-pitch and double-pitch roofs.

• Implemented the Labeling of steel structure elements tool. Labeling can be performed manually (by assigning a specific label) or automatically (with automated label generation).

  For automatic labeling, label prefixes must be set according to functional characteristics. Automatic labeling considers the function of the steel element, its cross-section, and the element length with the specified accuracy.

• Added layer search in the “Modeling layers” dialog. Two modes are available: partial and full match. In full match mode, the program also considers uppercase letters. By default, partial match mode is enabled.

• Added multiple selection of sections in the Section parameters dialog using Shift and Ctrl keys. This allows faster creation of section sets, transferring them from the project library to the general LIRA-CAD library, as well as copying and deleting groups of selected items at once.
• In the Default element parameters section of the Program settings dialog, the ability to expand the set of default properties for main objects has been added. Users can preconfigure frequently used and rarely changed parameters, which will be automatically applied when creating new model elements.
• For the function of displaying objects by properties and display modes, the set of visualization options has been expanded. New modes have been added: building layer color, column color by reinforcement type, colors of assembly stages, effective lengths, mass groups, loads, subtask sets, as well as load intensity visualization.

For clearer work in specialized modes, a graphical accent has been added — a frame around the perimeter of the workspace. In Block mode, the frame is displayed in blue, and in Editable analytics mode — in green, allowing the user to quickly identify the current working mode.

• In LIRA-CAD, parameters have been added for calculating dynamic load using the direct dynamic method with the Time history analysis system.

• Implemented an algorithm for preparing input data for the Mass redistribution groups tool, simplifying model preparation for calculations with mass redistribution.
• Added automatic collection of snow loads on slabs, inclined slabs, variable-thickness slabs, and roof types: single-pitch, double-pitch, and vaulted.

Snow load is collected considering load cases according to standards: DBN V.1.2-2:2006, DSTU-N B EN 1991-1-3:2010, NP to SP RK EN 1991-1-3:2003/2017, and SNIP 2.01.07-85.

• Added the ability to define a snow mound on inclined surfaces.

• An alternative method of defining moving loads has been implemented, adapted to the standard logic of LIRA-CAD tools.

  All moving loads from the library are now available directly in the Moving load command properties panel. The user selects the command, defines the trajectory line, chooses the required load from the list, and creates its path in the model.

  Custom moving loads can also be created and saved to the library — after that, they automatically become available in the command properties panel.

• Added the ability to apply uniformly distributed loads on curved surfaces. Application is performed through object properties.

• An algorithm has been implemented in LIRA-CAD for preparing input data for Fragment load calculation. This allows automatic creation of data for collecting loads on walls and columns without additional refinement of the design model in LIRA-FEM.

• Improved logic for determining loads during formation of additional assembly and post-stage loads. An Assembly load parameter has been added to all loads and load-generating objects.
• In the Object visibility filter dialog, load display management has been expanded: separate visualization and hiding parameters have been added for concentrated loads, linear loads, and surface loads.
• Load commands on the ribbon have been reorganized. The load panel is now structured by load content rather than by construction method, as before.

• Accelerated the triangulation process by 2–4 times (compared to previous versions of the program), allowing faster preparation of the model for analysis even when working with complex geometry and large design models.

• Implemented the Analytical plane tool, designed for aligning and binding model objects relative to a specified plane.

  The plane can have vertical, horizontal, or arbitrary orientation and can be used as a base reference element alongside axes and storeys. Objects aligned to the analytical plane maintain associative dependency: when the plane position changes, they are automatically rebuilt.

  Two interaction options are possible:

  • full binding of the object to the plane;
  • snapping/trimming the element to the plane at its start or end (e.g., for walls and beams).

  This tool simplifies parameterization and alignment of the BIM model, enabling geometry control without manual adjustments.

• Added new functionality to the “Link object parameters” dialog:

  • A list of linked object groups is now displayed — with the ability to select them on the model and identify the sample object;
  • When selecting an object on the model, it is now easy to see in the dialog which group it belongs to and by which parameters it is linked;
  • For each object, an “Object transfer” parameter has been added, allowing automatic movement of linked objects following the sample — even if they are located on different storeys.

• Implemented assignment of effective lengths for reinforced concrete elements. Previously, effective lengths were determined based on material properties. In the current version, additional methods have been added: manual input, as well as automatic determination of length or effective length factor.

  For convenience, summary table of effective lengths has been implemented. It allows centralized viewing, control, and editing of parameters for all model elements.

• For the Editable analytics mode, tools have been added to adjust the analytical representation of the model without changing the physical geometry. Implemented trimming of analytical wall plates and analytical beam bars, simplifying preparation of the design model, improving accuracy of the analytical model, and speeding up its editing.
• Expanded checks of input data correctness when creating the design model. Added verification of the presence of a linked soil model: if the task specifies linking a soil model to the building but the model is not found, the program warns the user.
• When generating a design model only for selected objects, error checking is performed exclusively for those elements. The display of data in the Project service information dialog has also been updated: errors and warnings are shown for the active project.
• Automatic organization of wall-column interaction is implemented both when trimming the wall edge by the column body and when splitting the wall into parts by a column located inside it. The analytical wall plate is trimmed by the physical dimensions of the column, and joint action of elements is established through PRB (perfectly rigid body).
• For controlling such connections, the Object connection management tool has been added, allowing viewing of linked elements, selecting them on the model, and removing them from the connection if necessary.
• Improved formation of models created by the Hyperbolic paraboloid tool. For flat variants of such objects, redundant triangulation lines (needed only for non-flat surfaces) are no longer created.
• The Triangulation splitting parameter allows flexible control of triangulation and formation of a higher-quality finite element mesh for this type of object.
• For walls forming a Bar analogue object, a set of improvements has been implemented for better preparation of analytical and design models. New settings have been added to BA parameters: Labeling, Extreme node search zone, and Intersect.

• If another wall adjoins a partition with a bar analogue and the BA line is close to the line of wall interaction, the program can shift the BA to the junction line considering the Match accuracy parameter.

  This allows forming a more correct finite element mesh without elongated elements of incorrect shape.

• New parameters provide flexible control of BA and FE mesh formation in the wall junction zone. With Intersect = No, the bar analogue is formed without shifting, while maintaining correct finite element shapes.
• When transferring BA to LIRA-FEM, data is displayed in the Structural blocks dialog: the label of the main element, BA label, comment with the name of the source element and the prefix Bar analogue, as well as the storey location of the element.
• Added support for transferring non-standard sections from LIRA-CAD to LIRA-FEM with interpretation as equivalent cross-sections, allowing more accurate consideration of specific frame element sections in calculation.

• In the Section positioning dialog, the ability to adjust the position of the analytical bar for a group of selected beams has been implemented. This allows setting the correct placement of analytical bars for the entire group of elements in a single operation without editing each one individually.
• For more convenient work and clearer analysis of analytical bar binding parameters, the corresponding properties have been moved to the object parameters. Now the user can directly view and edit the selected binding option: At the center of the bounding box, At the center of section mass, at the corners and sides of the section, as well as the offset values of the binding point along X and Y axes. This simplifies control of assigned parameters and speeds up adjustment of the analytical bar position.
• For more precise control of beam placement in the model, separate bindings have been added at the start and end of the bar. For each beam point, the standard set of bindings can be used: Free binding, From floor top, From floor bottom, and Specified level. This simplifies model construction and further editing of beam positions.
• A mechanism for explicitly defining relationships between beams has been implemented. Connections are formed based on PRB and displayed in the analytical representation even before the calculation model is created, ensuring more accurate control of modeling logic and clear verification of connections between elements.
• For “Cable” objects, a new construction method has been added — “Catenary line”. It simplifies modeling of cable-stayed structures with a specific sagging shape that must be considered in both the physical and design models.

• For slabs, an additional function has been developed to account for shape orthotropy.

  In the dialog box, the user can select the type of structural slab form and specify the necessary geometric parameters to determine its reduced stiffness and calculation behavior.

  The following options are supported:

  • one-way ribs in one direction;
  • two-way ribs in one direction;
  • one-way ribs in two directions;
  • one-way box slab;
  • two-way box slab;
  • beam grillage;
  • corrugated decking;
  • wavy corrugated decking;
  • slab on corrugated decking;
  • hollow-core slab with circular or oval voids;
  • solid slab.

• Added the option to select self-weight loading for inclined slabs and stairs.
• Added an alternative method for editing an inclined slab with free top and bottom binding.
• Improved load generation from spaces for inclined slabs.

• New functionality has been added to the Storeys dialog:

  • creation and deletion of storeys;
  • editing the height and marks of storeys, including for groups of storeys;
  • assigning names to levels and storeys;
  • assigning a level by mark.

• Commands Enable transparency and Disable transparency have been added to the project tree context menu. The degree of transparency is set in the Visualization settings dialog using the Element transparency parameter.
• In the new version, the individual position of the local coordinate system defined by the user is preserved. When switching between storeys, its orientation does not return to the initial state but remains in the previously configured position — at the required angle or with the necessary alignment to the object.

• For shafts, a Display on all floors parameter has been added, allowing their visibility to be maintained regardless of the current model level. This simplifies control of shaft placement in a multi-story structure, especially when working in Show active floor mode. The function is equally supported in both the physical and analytical representations of the model.
• The trimming mechanism for shafts has been expanded: openings are now formed not only in slabs but also in loads intersected by the shaft contour.
• An option has been added for conditional marking of shafts with fill, improving the clarity of their placement in the model and simplifying object selection during editing.
• For spaces, the handling of shafts and openings has been refined: if a shaft passes through a space or an opening is located within it, the corresponding volume is excluded from the space, and loads in these zones are not generated.

• Added an option for conditional marking of openings with fill, which simplifies visual analysis of their placement in the model and makes object selection more intuitive.
• Door and window openings modeled as loads from panels can now participate in staged construction modeling of the building and be used in the Montage tool.
• Improved display of overall dimensions for openings and recesses. When objects are selected, their dimensions are dynamically displayed, allowing more precise control of opening sizes in model elements. In the new version, permanent display of the linear dimension along the length of the opening has also been implemented. The dimension line clearly shows the object’s size and can be used for selection, which is especially convenient when working in top view, where the opening is physically hidden inside the wall or partition.

• New types of axes have been developed in the program, with the ability to construct along an arc, circle, spline, and Bézier curve.
• Added transformation of a 2D grid of coordination axes into a 3D grid for convenient spatial positioning. Optionally, additional floor levels and floor marks can be displayed.
• Automated assignment of properties for building axes imported from IFC. Previously, such axes could be duplicated and displayed on all floors, complicating work with the model. Now, imported axes automatically follow LIRA-CAD logic, showing axes only on the current floor, while retaining the option to display axes on all floors if needed.

• Added the ability to create a niche in a wall. The niche is created using the ±ΔH command.
• Added visualization of Face / Back for the wall. When a wall is selected, a local coordinate system is displayed showing the wall’s position.

• Implemented correct wall-to-wall trimming for cases where walls are not vertical but angled. In such intersections, both the physical and analytical wall models are formed correctly.
• Implemented wall-to-wall trimming not only for perpendicular and angled intersections but also for cases where elements lie in the same plane. This type of trimming simplifies model construction and speeds up adjustment of imported data when adjacent walls in the same plane partially overlap.
• Improved the trimming mechanism of partitions against load-bearing walls. If a partition is interpreted as a load, the load line now stops correctly at the perimeter of the load-bearing wall instead of entering its volume.
• Changed the mechanism for handling intersections of partitions with load-bearing walls. Previously, elements had equal priority during trimming, which in some cases led to incorrect shortening of the load-bearing wall and distortion of the calculation scheme. Now the load-bearing wall has priority: the partition is always trimmed along the analytical plate of the wall, ensuring more accurate formation of the building’s calculation model.
• Refined the mechanism for forming openings from ventilation ducts in walls: openings are created based on actual intersections with walls regardless of the floor affiliation of elements.
• For partitions interpreted as loads, the mechanism for forming loads when trimming against an inclined plane or slab has been refined. In such cases, the load is determined by the actual trimmed geometry of the partition and is formed not as uniform but as triangular or trapezoidal.

• Added transfer of source data on columns to LIRA-FEM in the form of a pair of nodes for skew calculation.

• Implemented creation of capitals under an inclined slab.
• Implemented multiple selection of capitals and sub-columns with the possibility of further adjustment.

• Further development of the LIRA-CAD graphics subsystem based on a programmable rendering pipeline has made our graphics even more expressive and interactive. The speed and quality of visualization have been significantly improved.

  Capabilities have been expanded for both the latest hardware and “time-tested” video cards. Alongside existing visual effects such as cast shadows, surface relief, diffuse shading, and others, new features include dynamic “sliding” highlighting of structural elements following the mouse cursor movement, and delayed “lazy” highlighting of structural elements in the area of interest. These reveal hidden geometry and make user interaction with the model more efficient.

• Implemented support for a composite BIM model based on several linked tasks. The “Load building” command allows connecting individual buildings from other projects into the master project not as a copy of geometry, but as dynamically linked objects.

  When the source file changes, the connected building can be updated with the “Update building” command without re-import. Along with geometry, materials, loads, assignments, and other configured building parameters are transferred.

  Calculation is performed on a single composite model, allowing the object to be considered as a unified spatial system taking into account the mutual influence of all connected parts.

• Implemented the “Compare building” function, designed for analyzing model versions and identifying changes between project variants.

  The dialog allows displaying:

  • added objects — in green;
  • deleted — in red;
  • modified — in blue.

  For convenient work, filtering by structural objects, grouping, and sorting of changes by type, floors, and object types is provided.

• Added a function to create a new building based on selected project objects. The chosen elements are transferred from the current building to the newly created one while preserving the floor structure of the original model.
• Improved project structure handling: in the new version, the user-defined state of the tree expansion is preserved.

• New types of loads have been added:
• Warping at nodes accounts for the inadequacy of the cross-sectional plane of a bar; it is important when for analysis of the thin-walled structures.
• Bimoment at nodes takes into account the moment arising from a force distributed along the height of the cross-section.
• Bimoment by line is mentioned to model a distributed bimoment along an element of the structure.

• Dynamic modules have been added: (22) Impact, (23) Impulse, and (50) Earthquake (AzDTN 2.3-1-2010, modif. on Jan 01, 2014).

• In the "Parameters for load case" dialog box, the "Scale for presentation of loads" parameter has been added for the selected load. So, it is possible to change the scale of concentrated, linear loads and surface loads, ensuring a more illustrative visualization.

• Location of the colour palette for visualization of analysis results can be customized (in the LIRA-CAD meshed model), including for the visualization of analysis results in the "RC expert" module.

• An option for loads on the staircase has been implemented: to indicate whether the load is included in the additional load case during assemblage.

Beam

A beam can now be modelled as a bar or plate element. In the new version for beams modelled as plates, it is now possible to specify the design location of the plate - vertical or horizontal. When the analytical representation for the beam is defined as a plate, the Bar Analogue option becomes available.

In the Beam properties dialog box, the parameters for snapping the element relative to the grid line are extended; they include the physical location of the cross-section and the location of the analytical bar. These parameters are now also available in the Filter by parameters and Select by criteria dialog boxes.

Optimised behaviour of the beam in the mode of manual editing of the analytical model; it includes the option to divide the beam into several fragments.

Partitions

R search and L search parameters are added to the object properties. In some cases, when a partition physically rests on a slab, the analytical model representation shows the partition as a linear load and the slab as a plate. If the Align Analytical Model property for the slab is defined as Auto, it can cause that the segments of the analytical plates of slab are shifted to plates of walls or bars of beams. As a result, the load from the partition may not be applied to the slab.

To avoid this case, the added parameters R search and L search ensure that the load is correctly distributed in the described situation and is properly applied to the structural object.

Piles

The program has been updated to provide a manual mode for altering pile models. With this mode, you can shift the pile analytics' location for more precise positioning and separate the pile's analytical bar from its actual volume. This enhances the quality of the FE mesh generation for the beam grillage. It is also possible to consider the influence of the foundation slab's punching shear beneath the pile action.

Grid lines

Previously, if the grid lines belonged to a specific storey and only the current storey was displayed, the grid lines became invisible as they could be on a hidden storey. Now it is possible to enable visualisation of grid lines across the entire building; in this case the grid lines remain linked to their storey. This is particularly useful for IFC import, where the same grid lines may be duplicated on each storey. In LIRA-CAD module, such duplicates can be removed, and thanks to the new setting the grid lines will be correctly displayed in certain views.

Staircase

The weight of the stair treads is now also considered when modelling the load from the dead weight of the structures. This allows for more accurate modelling of the load from these structural elements.

Opening / Door and Window Opening

New options to copy and transfer openings between projects and buildings. For convenient work with openings, their dimensions may be visualized in 3D model. These dimensions are also represented as additional objects that allow you to select the opening when you click on it. This option may be defined in the Filter for object visualization dialog box. It is especially helpful when you work with the model in the top view mode.

Shaft

The main purpose of shaft - is to create openings in slabs that intersect with volume of the shaft. Shafts can be generated either in the physical representation of the model or in the analytical one. In the analytical mode, the shaft contour can be 'magnetized' to analytical plates (walls and slabs), as well as to analytical bars (beams and columns). So, the required openings may be generated more accurately and quickly on several typical storeys at once.

However, the inter-storey staircases are often included in the shaft volume. To ensure that they are correctly represented in the model and are not cut out of the slabs by the shaft, a special property is added to exclude the influence of the shaft on such zones.

Object properties

New tool Additional Properties of Object that allows users to create and manage additional parameters for objects of the model. These parameters provide more detailed control over the model and adapt data to specific project requirements.

The dialog box of this tool displays both custom parameters and standard object properties; it simplifies the data management and provides convenient access to all necessary characteristics in one place.

Linking parameters

The Link parameters of objects function is mentioned to establish a link between similar objects (column, beam, slab, inclined slab, wall, openings in walls, spaces and stairs) based on a selected parameter or group of parameters. The first selected object becomes a base object. It serves as a reference for other objects (followers). Objects may be linked by any parameter available for the selected object, including geometric location, dimensions, material and other parameters. Changes to the parameters of the sample object are automatically applied to all linked follower objects, ensuring data consistency. Additional tools allow you to see by which parameters the objects are linked and visualize the created links in colour. This option reduces the risk of errors and allows you to focus on more complex tasks, trusting routine changes to the software.

Modifying the contours manually

New option to edit manually the contours for Capitals and Column bases. Now it is possible to select capitals or column base as a separate object with its own set of parameters.

Tool: Create by sample

The Create by sample tool allows you to create new objects based on information about existing project elements. This tool greatly simplifies and speeds up the modelling process.

How the tool functions:

For example, if you want to add a column on the 4th storey and a column with the required parameters already exists on the 1st storey, you can select this column and activate the Create by sample command. The program will automatically switch to the mode of creating a structural object with similar properties.

Customization:

Once the command is activated, the user could change any parameters that have been transferred from the selected object. This allows you to minimize data entry and focus only on modifying key parameters.

Benefits:

• Simplify object generation: To add elements quickly based on the elements available in the model.
• Reduced risk of errors: To auto copy parameters; it reduces the incorrect data entry.
• Speeding up the work: To reduce the time required to generate a model.

The Create by sample tool provides accuracy and convenience when creating new elements and duplicating elements; it speeds up the process of model generation.

Tool: Twist angle of the beam section along the trajectory

This tool allows you to model the behaviour of a structure more accurately. The tool takes into account the physics of beam twist along its axis; it is especially important when in analysis of complex 3D structures.

The twist data is not only visually displayed in the model, but is also correctly taken into account when the whole object is divided into finite elements for analysis.

Transfer of project description from LIRA-CAD to LIRA-FEM

In the new version of the program, it is possible to transfer the project description from LIRA-CAD module to LIRA-FEM program. The project description, which is not usually reflected in the project title, can be defined by the user in the project's properties. Now the user could record the data describing the specific features of the object and other important data in LIRA-CAD and transfer it together with the project to LIRA-FEM.

The following loads can be generated:

• Impulse load at nodes and along the line. For the load, the following data should be defined: load case, load value, load direction, pulse shape, duration of load, period of repetition of the load and number of repetitions of the load. The load may be automatically snapped to the structural object of the building.
• Harmonic load at nodes and along the line. For the load, the following data should be defined: load case, load value, load direction, load diagram, load amplitude, phase shift. The load may be automatically snapped to the structural object of the building. For correct analysis of the dynamic load "Harmonic (24)", a full set of necessary parameters is provided, including the inelastic strength factor of material and the forced frequency of the external action, as well as taking into account the frequencies preceding the specified one.

New types of loads may be created: pyramidal load (property of Surface Load tool) and load from the weight of the coating on the object surface (property of Special Load tool).

It is possible to copy loads from one load case to another, including with a scaling factor. It is also possible to copy load case together with loads. In the Load Editor dialog box, there are options to display loads by area in colours according to their intensity for one or more selected load cases. An option to revert the loads to the load colours is also provided.

You could manage loads (assign, remove loads and select elements that this load is applied to) from the Project Structure window. It is available for load types: Special Load, Soil Pressure and Ice Load.

Ice load

The tool for collection of ice load is substantially improved:

• Support for building codes: DBN B.1.2 - 2006, NP to SP RK EN 1993-3-1:2006/2011, SNIP 2.01.07-85;
• To collect ise load to the Rope element with account of regulatory documents;
• To collect ise load on structures above 100 metres, with account of regulatory documents;
• To generate the ice wind with account of regulatory documents.

Wind load on the roof

In addition to automatic wind load collection for flat, shed and gable roofs, wind load may be collected from the vaulted roofs in accordance with DBN B.1.2 - 2006 and EN 1991-1-4 is implemented.

Node: Explosion

Node Explosion is mentioned to automate all processes related to the determination of the explosive load intensity and its application to the relevant structural elements, taking into account various explosion parameters (mass of the charge, explosion position (in the air or on the surface), the step for approximation of the overpressure distribution function, the load case No., etc.). Overpressure on structural elements is calculated according to the international standards (UFC 3-340-02: Structures to Resist the Effects of Accidental Explosions). The load can be applied both statically and dynamically. In the latter case, the program automatically generates graphs of the time impact of the impulse.

Note:

When calculating the load intensity, the current version of node does not consder aerodynamic coefficients.

Special load

The Special Load element is mentioned to model pressures of liquids and gases on tank walls, as well as other loads distributed over the area of plate or bar elements. This tool provides realistic modelling and helps the user consider external actions on the structure.

Features and usage:

• Apply to the elements of the model:
  

  To assign a special load to specific elements or groups of elements, select the Special Load object and the appropriate elements of the model.

• Multi-level arrangement:
  

  The special load is added to the level of the active project, so it may be applied to elements located on different storeys of the model. This simplifies work with loads in complex projects where elements are distributed on several levels.

• Generate elementary loads:
  

  When creating a meshed model, each Special Load is converted into a set of elementary loads. The parameters and method of application of these elementary loads depend on the settings for the Special Load object.

• Verify visually in analytical view:
  

  The distributed loads can be visually verified in advance in the analytical representation of the model; it enables the engineer to confirm that their application is proper prior to analysis.

The use of Special Loads in the LIRA-CAD module makes it possible to effectively take into account complex loads on the structure, ensuring high accuracy of modelling and analyses.

Space load

In the Space contour tool, with the Interpretation option indicated as the Load, it is now possible to apply loads to the following objects: inclined slabs, slabs with variable thickness and stairs.

Moreover, in the new version for this element, there is an additional set of checkpoints displayed at the top of the space. This greatly simplifies and speeds up the process of modifying the space contour.

Auto snap the load to the element

The new version of the program introduces the Load Snap option that allows you to automatically snap a load to a structural element. Before placing the load in the model, the user can activate the Snap command and then select the structural element to which the load will be attached. Then the load attached to the certain object is generated.

Example:

If you design a metal frame where the purlins are supported by main beams, the roof weight can be defined as a linear load along the purlins. If the step of the purlins is changed, the appropriate load will automatically update its location to match the new location of the elements.

Benefits:

• Accuracy and reliability: The load is always linked to the relevant structural element.
• Auto update: When the layout of the elements changes, the load adapts automatically without the need for manual modification.
• Simplifying the modelling process: The function reduces the probability of errors and ensures that the model is generated correctly.

This feature improves the usability and accuracy of the design procedure by automating the work with loads and minimising the risk of errors in case of modification in structure.

Load cases (dialog box)

The following options are added:

• to generate data for subproblems, collect masses, and perform stability analysis;
• to perform a number of operations via the shortcut menu, including:
  • to define dynamic loads (mass collection);
  • to colour loads by colours of load cases;
  • to colour loads according to their intensity;
  • to define parameters for load cases;
  • to copy loads from one load case to another.

Subproblems

New technology to define the input data for the Subproblem method. With this technology, many independent sets of subgrade moduli and sets of coefficients to modulus of elasticity can be used in a single design model.

Each loading stage may have a different set of parameters based on the subgrade's properties or maintenance conditions. Therefore, the soil's heterogeneity and the unique features of the foundation-structure interaction may be taken into account; this allows for a more realistic description of the system's actual conditions.

Furthermore, the flexibility to assign different coefficients to the modulus of elasticity at every stage of analysis creates additional opportunities for more precise design solutions.

Input data for the stability analysis

In the new version of LIRA-CAD module, it is possible to define the input data for stability analysis of structures. Users can define key parameters and select objects for analysis. Main options:

• To select the calculation method: by forces or by DCLs.
• To define load cases: either loads or DCLs to be considered in the analysis procedure.
• To include elements in the analysis: in the properties of objects you could define whether they are considered in stability analysis.

The defined parameters are automatically transferred to LIRA-FEM. So, it eliminates the re-entry of data, reducing the risk of errors and speeding up the modelling and analysis process.

Condensation of masses

New option to define the Condensation of masses to optimise dynamic analyses, especially when analysing vibrations of structures. Only masses of the main structure are considered when searching for mode shapes, while the masses from the flexible part (masses of selected elements in which natural vibrations are not of interest to the user in this problem) are concentrated in its support nodes (support nodes of selected elements). Also, it is now possible to perform Selective account of masses in elements to consider exactly the masses of selected elements for dynamic analysis.

Unification of bars

New option to preliminary unify bar elements (beams and columns) for analysis of reinforcement or metal sections. In the Unify bars dialog box, all elements of the model are listed: columns, beams, as well as elements of trusses and beam systems. The table contains data about name of the element, its length, section and material. Unification can be performed on the basis of tags assigned to elements, or unified groups of structural elements (UGSTE) can be created. A graphic presentation of elements by tag colours is available now. Unified groups (created on the basis of tags or assigned to UGSTEs) can be transferred to the VISOR module of the LIRA-FEM program.

The unification table in its current state can be placed on the drawing as an editable table. You can also export its contents in TXT or CSV formats for Microsoft Excel.

Perfectly rigid bodies (PRB)

In previous versions of the program, there was an option to arrange the combined behaviour of beams and slabs with the Offsets tool that provides a reliable connection between elements. In the new version, an additional option - Perfectly rigid bodies - is added, providing an alternative modelling strategy.

The length of the PRB is determined automatically based on the distance between the analytical models of objects and is updated in real time when any of them is moved. In the analytical representation mode, the PRB model more clearly demonstrates the interaction between the slab (plate) and the beam (bar).

With this approach, the interaction between beams and slabs can be described more precisely and adaptably, ensuring that they behave together as a single system. The use of Perfectly Rigid Bodies extends the functionality of the program, offering a new way of modelling such connections and increasing the accuracy of calculations.

Triangulation

Triangulation regions in the slab above the walls are updated when the walls are moved or modified. New option to update the dimensions of an existing triangulation zone and the step of approximation of its contour lines. In previous versions, it was necessary to delete the old triangulation zone and create a new one with updated parameters.

Triangulation points in the slab above/below the walls are created automatically for flexible customization of triangulation mesh. To manage the triangulation points, use the following parameters: step of triangulation points and number of rows. You can also specify the number of rows with fixed step of triangulation points. In this case the remaining rows will have a transitional step of triangulation points. The value of this transitional step can be in the range from fixed step to user-defined step of triangulation in the plate.

Additional grid of triangulation lines

To improve the accuracy in modelling of slab triangulation zones, a new tool Additional grid of triangulation lines is introduced. It allows the user to define the cells by which the slab is divided into finite elements, providing more detailed modelling.

Key options:

• To define parameters for the cell: The user specifies the dimensions of the cells to be used for triangulation.
• To select the triangulation zone: Define the slab on which the additional grid will be created.
• To define the generation method: Depending on the needs of the project, you can select different shapes for the additional zone: rectangle, sloping rectangle, inscribed or circumscribed polygon.
• To locate the additional zone: The tool allows you to place triangulation zones at key locations to create a denser and more accurate FE mesh.

Benefits:

• Easy to set up and use: The tool is intuitive and easy to set up.
• Visual clarity: The user can immediately see how the future triangulation mesh will look like.
• Modelling accuracy: Provides optimal densification of finite elements in important zones of the meshed model, improving the quality and accuracy of the analysis.

This tool simplifies the creation of complex meshes and allows for precise control of the finite element structure, especially in critical parts of the model.

A new object - a Lift Pit is automatically created on the basis of an opening defined in the foundation slab, and its dimensions depend on the dimensions of this opening.

The pit has a set of Slab and Wall parameters that can be modified parametrically (thickness, boundary conditions, interpretation, etc.). For the walls of the pit, it is possible to define a thickness variable in height.

To select the analytical representation of the pit walls, use the parameter Create walls - Yes/No:

• Create walls - Yes - the walls and the slab have an analytical representation of the Plate;
• Create walls - No - the plate has an analytical representation Plate, the walls are replaced with an Offset.

In addition to the already available special elements such as Free Spring, Damper and Bar, a new tool is added - Plate. This element has all the standard properties of the Slab type element, but its functionality offers a more flexible approach to introducing flat elements into the model.

The Plate tool allows you to generate elements that can be 'magnetized' to the checkpoints of other objects in any way. This generation method greatly simplifies the process of integrating an element into complex structures and offers more precise location in the model. With the help of this tool's versatility and user-friendliness, engineers may effectively build complicated systems by taking into consideration the geometric and structural properties of other elements in the model.

There is now technology to define the input data for modelling of cable-stayed structures. With this technology, a unique product called Rope can be created. For this element, it is possible to define key parameters necessary for accurate modelling of such structures:

• Type of section , with the rope profile indicated;
• A method for dividing an element to consider its geometric and design properties;
• The tension; so, the stress in the structure will be considered properly.

For complicated cable-stayed systems, including stadiums, roofs, bridges, and other structures with tension elements, this component offers more precise and effective modelling. With this method, the modelling of objects with unusual features is optimised and the accuracy of design solutions is increased.