Preprocessor LIRA-CAD

Design model is generated according to the information 3D model in LIRA-CAD
A wide range of tools to generate high-quality design model

Input data for design modules

Design parameters of steel structures
When the model is generated in LIRA-CAD, it is possible to assign design parameters to reinforced concrete, steel or masonry reinforced materials. These parameters will be applied later for analysis of reinforcement or check/selection of steel sections in VISOR-SAPR module.

Perfectly rigid bodies (PRB) and offsets

Offsets in beams
Automatic generation of perfectly rigid body (PRB) in the zone of column-slab connection makes it possible to create a non-deformable region in the slab along the contour of the column cross section. Automatic PRB generation may be also used for wall-slab, wall-wall and beam-slab connections. In addition to the PRB, it is possible to 'attach' the bar to the plate with offsets (beam-plate, column-wall connections); the length for an offset is determined automatically to consider the eccentricity in non-coaxial elements.


Parameters to create load from soil pressure Edit load case (dialog box)

When design model is generated, the dead weight of elements is computed. Load from non-load-bearing walls made of single-layer or multi-layer materials is computed. It is possible to create and edit concentrated, linear, surface loads (distributed uniformly and non-uniformly).

The following options are implemented: automatic collection of wind load, pulsation and earthquake loads, analysis of load from snow mound and collection of ice load according to different building codes.

There is a tool that enables the user to compute the soil pressure and apply it as a horizontal load to the walls of the basement. For a beam system, there is an algorithm that converts uniformly distributed load into load on beams. In the 'Edit load cases' dialog box, you could define the type of load case, safety factor, duration coefficient, sign variation, create groups of accompanying, united load cases and mutual exclusions. In this dialog box it is also possible to automatically generate tables of design combinations of forces (DCF), design combinations of loads (DCL) or create user-defined combinations.

loads playlist

Punching shear contours

Punching shear contours
Punching shear contours are generated automatically by different building codes depending on the cross-section of columns, slab thickness, the presence of closely spaced holes or the edge of the slab. Contours are generated for floor slabs and foundation slabs.

Boundary conditions

Boundary conditions

Connections between elements are simulated with different support options: rigid, pinned, free support. You can also take into account the eccentricity of support elements.


Define piles
The program has a wide range of different supports: pinned, roller, fixed and user-defined support. Moreover, elastic support (FE56) with the option to define the stiffness in certain directions.
For the foundation slab, it is possible to define subgrade moduli C1 and C2 or take into account the soil model in the analysis by attaching it to the building model. In addition, pile foundation may be used. Bearing capacity of such foundation may be defined either as the load and settlement or the pile stiffness may be determined by a soil model. For a foundation slab, it is also possible to compute the compliance in horizontal direction.
Computing horizontal stiffness for the foundation slab supported with soil
Updatable soil model

Change FE type and define numerical stiffness

Change FE type and define numerical stiffness
For objects of the type column, beam, wall and slab, it is possible to select the type of FE that will simulate this object. For selected FE type, the stiffness may be either computed by the section (thickness) and material or it may be defined numerically. It is possible to introduce reduction factors to the stiffness parameters.

Triangulation lines and points

BA above the opening 
BA for walls

Automatic generation of bar analogues (BA) is available in the LIRA-CAD module.

Bar analogues enable the user to analyze composite structures simulated with a set of finite elements of plates/shells/solids as bars. With the help of bar analogues for composite structures (pylons, wall beams, prefabricated floor slabs, lintels, diaphragms, building stiffness cores, etc.), it is possible to obtain not only internal forces in the original finite elements, but also internal forces in the design sections of the structures and then design such structures.

When generating BA, simple rectangular sections are automatically recognized from linear sections of a wall, a slab rectangular in plan, a lintel above and below the opening, pylons or beams, represented in the calculation model by plate FE.

New settings for intersections of elements in the meshed model (SAPFIR 2020). Acceleration of triangulation. Triangulation lines. Triangulation template may be saved and used later for other projects. Vertical and horizontal triangulation lines for walls. Mesh refinement in areas near supports.

Triangulation lines and points

Triangulation lines and points
Flexible tools to create additional lines and triangulation points enable the user to thicken critical areas and refine the triangulation of the model to the required degree. In the column properties, you could set the step for dividing the zone above and below the support. For windows and doors it is possible to create triangulation lines from openings to wall edges. Inside the slab you can create a triangulation zone with different step and direction of local axes; there is a tool for automatic generation of triangulation zones above and below walls. Around the openings in the slab, triangulation may be thickened in case triangulation points are defined automatically.

Intersections and triangulation

New settings for intersections of elements in the meshed model (SAPFIR 2020). Acceleration of triangulation. Triangulation lines. Triangulation template may be saved and used later for other projects. Vertical and horizontal triangulation lines for walls. Mesh refinement in areas near supports.


Defining assemblage stages
ASSEMBLAGE system is mentioned to simulate the stages of erection (assemblage) of the structure. The sequence for erection of the building may be either generated automatically or defined manually as events. Objects of assemblage stages are checked with assemblage animation. When design model is generated, the program automatically generates the stage-by-stage and additional assemblage load cases as well as assemblage tables in terms of VISOR-SAPR module.


Validation of the model
To search for errors and inaccuracies during model generation, you can check the correctness of the model with the 'Auto-correction' option. This enables the user to find out an error at the very beginning and avoid it further in the model. The check is made automatically when the floors are copied and when design model is generated.

Model continuity and distance to supports

Distance to supports
The program enables you to check the model for the continuity – combined behaviour of elements. This check will help you identify places where the intersections of objects are not generated or where there are no supports in the base. Information about the distance to supports is displayed as a colour palette.


Triangulation options
  • Triangular - regular triangles are generated for all plates.
  • Adaptive quadrilateral - triangulation starts from the supports and regular quadrilaterals are generated above supports.
  • Quadrilateral - triangulation starts from a span and regular quadrilaterals are generated in the span.

Triangulation with a certain method and step may be assigned to specific objects. The triangulation mesh depends on triangulation lines and points.

Triangulation options

An overview of the new triangulation features introduced in SAPFIR 2021. Options to smooth the FE mesh and how it affects triangulation. Options to create triangulation lines in walls and to create triangulation zones in slabs (triangulation parameters different from those of the main slab may be assigned to these zones). Option to define direction for unification of local axes for slab zones.

Mosaic plots for properties and geometry

Mosaic plot of mesh quality
The meshed model may be evaluated with various mosaic plots:
  • quality of plates;
  • area of plates;
  • min plate ribs;
  • min plate angles;
  • lengths of bars;
  • rotation angles of bars;
  • and mosaic plots for linear loads.

Analysis and evaluation of output data

Mosaic plot of displacements from DCL
It is possible to send the meshed model for analysis directly from LIRA-CAD module and then evaluate analysis results (displacements, forces in bars, stresses in plates and forces in 1-node elements) also in LIRA-CAD module in a simple way. The results may be evaluated either by load cases or by DCL.

Output data (Analysis results)

New tools to evaluate analysis results in SAPFIR 2020 in a simple way. Safety factors. Commands for check the correctness of design model: split storeys and distance to supports. It is possible to launch analysis from SAPFIR module and evaluate displacements, stresses, forces in elements by load cases and by DCL. Generation of DCL according to Eurocode EN 1991-1-4:2005.

Evaluate the software

If you have any doubt, download the Demo version and evaluate the program or contact our Support Team for more details.

Demo version or Request online presentation