### Changes and additions of SP LIRA 10.12 R2.1

### Changes and additions of SP LIRA 10.12 R2.0

- Added equivalent bars and shells, which allow to reinforce solid bodies
- Implemented the output of graphical information based on the results of nonlinear analysis for cross sections of physically nonlinear bars
- Supplemented the displayed graphical information on the results of nonlinear calculation for sections of physically nonlinear plates
- For linear bar FE (including those with a cross section variable along the length), the output of normal, tangential, principal, and equivalent stresses has been implemented
- For linear shell FE (including multilayer ones), the output of normal, tangential, principal, and equivalent stresses has been implemented
- In the " Screen Image" mode, implemented custom templates for automatic generation of dynamic images
- Implemented DCF according to Eurocodes (with saving and visualization of the coefficients with which loadings are included in DCF)
- Added summation of forms for multiple frequencies
- Implemented the possibility to perform calculation on uncoordinated grids
- Added mass eccentricities for modal analysis and DYNAMICS +
- Implemented cross sections of plates with different types of ribs and waves
- Avalanche choice for bars/plates/solids has been added
- Implemented plate FE of nonlinear elastic link (FE 290)
- New mode «User Results»
- For physically nonlinear analysis, added the possibility to use cross sections from rolled steel
- Added new physically non-linear interface (contact) elements (FE 268 and FE 269). Implemented an auto-generation of these elements in the "Add Element" mode
- Implemented table editing of model parameters
- Implemented the determination of the components of the torsional moment (free and bending torsion) for the 7 FE type
- Implemented the calculation of the non-stationary thermal conductivity problem
- «Dynamic input» added when specifying architectural elements Reinforced concrete structures
- Implemented calculation of steel-reinforced concrete sections with rigid reinforcement without and with an external pipe
- Added possibility to specify various reinforcing inclusions for structural analysis of cross sections of bars and plates Wooden structures
- Added wood materials database
- Added 4 types of cross sections of bar elements for the analysis of wooden structures
- Implemented the calculation of wooden structures according to standards of the USSR, Ukraine, the Russian Federation and the European Union Soils
- The SOIL system supplemented by the standards of EN 1997-1:2004 and SN RK EN 1997-1: 2004/2011, when determining the settlement of shallow foundations and calculating the coefficients of subgrade reaction C1 and C2
- Implemented the calculation of the settlement of a single pile according to the standards of EN 1997-1:2004 and SN RK EN 1997-1: 2004/2011
- Added calculation of design soil resistance
- Implemented checking the strength of the underlying layer at the base of foundations Metal Constructions
- Sections of metal structures have been supplemented with trussed three-branch cross sections
- Implemented a utility for calculating a sheet of flooring and bunker sheathing Import and export
- Implemented conjunction with Advance Steel
- Implemented conjunction with Renga
- Plugin capabilities for Autodesk Revit have been significantly expanded
- List of other innovations

Contants

Design and graphical environment## Design and graphical environment

When forming the design model of a building or structure, certain structures can be modeled by both bar and plate or solid finite elements. Each of these types of elements has their advantages and disadvantages. Sometimes a structure of complex shape cannot be calculated as bars or plates. And the correct calculation can be made only with solid elements. On the other hand, unlike bars and plates, for solid elements there is no selection and structural design verification according to regulatory documents. Point and distributed reinforcement can be calculated for a bar, and only distributed reinforcement for a plate. Considering the advantages and disadvantages of forming the design model by different types of elements, the equivalent elements, which allow to collect internal forces from plates and solids on equivalent elements of a lower order in order to select and check the design according to the selected standards, have been added in SP LIRA 10.12.

The concept of equivalent elements is based on the principle, that the total internal forces in the center of the equivalent element correspond to the sum of the nodal forces and moments in the element from which we collect the internal forces. Nodal forces and moments here mean loads that lead to stresses in the element. For a separate bar equivalent element, those nodes fall into the collection of internal forces, which are placed between normal planes passing through two nodes of an equivalent element. For plates, those nodal loads are collected that lie on the normals to the equivalent plate, passing through the nodes of the equivalent element. This fact for plates must be taken into account, in order not to lose those loads in the nodes, which are not projected into the nodes of the equivalent plate.

Creation of equivalent elements in the program is carried out either using autogeneration, or by constructing them manually like regular elements, changing the element type to the corresponding one.

To automatically generate the elements of the equivalent plate, you need to select the solid elements, from which it's necessary to collect the internal forces, and to select the nodes, which will belong to the equivalent shell. Then, being in the «Equivalent elements» mode, select the «Add plate elements» and «Add equivalent element» items. In the figure below, this procedure is performed for a ribbed floor slab.

To automatically generate the equivalent bar, you need to select the plate or solid elements, from which it's necessary to collect the internal forces, and to select two nodes, which will be the start and end of the equivalent bar. Then, being in the «Equivalent elements» mode, select the «Add bar element» and «Add equivalent element» items.

In order to construct the equivalent element manually, you need to specify the bar – for equivalent bar element, the plate – for equivalent plate element, and then assign the appropriate type (610 – for equivalent bar and 642, 644 – for equivalent plate). Then select the equivalent elements and the regular elements, from which the internal forces will be collected, and being in the «Equivalent elements» mode, click the «Change List of Elements» / «Replenish List of Elements» button, depending on what needs to be done.

The figure shows an example of a ribbed flooring, built with solid elements, which can be considered as bar elements (tee-beams) and shell parts (plates). Equivalent elements are not involved in the FEM calculation. After the FEM calculation, the internal forces from the main design model are collected on the specified equivalent bars and shells, for which it is already possible to carry out the corresponding design calculations (proportioning and check of reinforced concrete, steel-reinforced concrete, metal and wooden structures).

As an illustrative example, below there are two options for modeling the junction of a column to a foundation slab. In one version (on the right), the column is rigidly connected to the foundation slab through the ATT at the point of contact, and in the other (on the left) the contact point is modeled by solid elements, which more accurately reflects the stress-strain behavior of the model and gives a smoothed result. Internal forces from solid elements are collected into an equivalent bar element.

When using ARB, peaks of internal forces are observed, due to which, when calculating the reinforcement, we obtain peaks of reinforcement values.

Below is a comparison of the obtained values of transverse reinforcement.

The results in the places of concentration differ significantly in both the internal forces and the reinforcement calculated from these internal forces. At the same time, without creating a new model using an equivalent element at the junction point of the column with the foundation slab, it is possible to select reinforcement taking into account punching shear.

When using a bunch of elements of a higher order and equivalent elements, more adequate internal forces are obtained at the places of concentration and, accordingly, more accurate results of the design calculation.

Nonlinear analysis of bars has been implemented in SP LIRA long ago. In the SP LIRA 10.12 version, the output of graphic information on the cross sections of bars for the analysis of results has been implemented. As before, for nonlinear analysis, it is necessary to specify the splitting of the bar section into cells, along which the calculation will be performed.

In the SP LIRA 10.12 version, in the fracture mode, when you click on the bar with the mouse, the result of the calculation for each cell appears.

Since the nonlinear analysis of the bar is carried out only for normal stresses, stress and strain are available for viewing. If a reinforced concrete cross section is calculated, then stresses and strains in reinforcement are also available for viewing.

In a nonlinear calculation, the plate thickness is divided into 21 layers in height.

To view the calculation results for each layer, enter the fracture mode and click on the plate. You can view stresses and strains by the axes of alignment, principal stresses and strains. If the deformation values for the top and bottom layers have different signs, then the position of the neutral axis in each direction is also displayed.

If you are calculating reinforced concrete, then viewing stresses and strains is also available for the reinforcing material.

In SP LIRA 10.12, in the «Principal and equivalent stresses» mode, for linear bar FE (including those with a cross section variable along the length), the possibility to display more detailed information on the specified element has been added, in case the «Stresses in cross section of element» checkbox is marked. The following data can be displayed:

* normal and shearing (tangential) stresses and strains,

* principal stresses,

* equivalent stresses.

In addition, it is also possible to set the internal forces by choosing the «Specify internal forces» item in the «Cross section number» drop-down list.

In SP LIRA 10.12, in the «Principal and equivalent stresses» mode, for linear plates (including multilayer ones), the possibility to display more detailed information on the specified element has been added, in case the «Stresses in cross section of element» checkbox is marked. The following data can be displayed:

* available stresses and strains by directions,

* principal stresses and strains,

* equivalent stresses.

In addition, it is also possible to mark the «Specify internal forces» checkbox and set the internal forces in the plate manually.

SP LIRA 10.12 provides users with the possibility to create templates with auto-generation of images for analysis and documentation of calculation results. The template stores data on the load number and type of results.

To create templates, you can use the «Screen Image» mode. Select the «Dynamical Image» item in the drop-down list with save options and copy a screen image with desired data. Right-click on the resulting image or several selected images and choose «Add to templates». As a result, the image data will be saved in the list «General templates» at the bottom of the window, where they can be moved, renamed and used as templates for a different kind of a given diagram or another problem. Also in this list you can create folders and apply all the templates in it with one click.

Examples of using

Template 1 «Displacement along UX _ LCS [1... Static loading]»

The resulting image from the template 1 for View 1

Template 2 «Internal force Mx [1... Static loading]»

The resulting image from the template 2 for View 2

In computational practice, two similar, but fundamentally different ways of solving the same problem are used – calculating the most dangerous load combinations: Design Combination of Forces (DCF) and – Design Combination of Loads (DCL). In contrast to the DCL, where the characteristics of SSB of the design scheme are obtained, on which several loadings simultaneously act, DCF is looking for a disadvantageous combination for every element tested or every cross section of a bar element. For n load cases, without imposed logical connections, we will have (2^{n}-1) load combinations. With real values of the parameter n, the number of possible combinations becomes so large, that solving the problem by direct enumeration of options turns out to be unrealistic.

DCL calculation is widespread in Europe and America. When implementing in SP LIRA 10.12 the regulatory documents EN 1990:2002, SP RK EN 1990:2002+A1:2005/2011 and DSTU-N B V.1.2-13:2008 (hereinafter referred to as Eurocode 0), the question arose what to implement first. The choice was stopped at DCF, because in the general case of SSB, the criterion for determining the dangerous combination is the extremum of the elastic potential at any point of the body under the action of forces on it from many loadings. This formulation easily takes into account the features of the stress behavior of finite elements of various types. This allows you to significantly reduce the number of considered combinations without losing the most dangerous of them. For bar elements, the problem of choosing combinations is reduced to finding the extreme values of normal and tangential stresses, calculated at the characteristic points of the section. Therefore, the criteria here are the extreme stresses at these points of cross section.

According to Eurocode 0, the following limit states are considered:

– critical (combinations of actions specified in the expressions (6.10) – (6.12b), should be used when calculating by Ultimate Limit State);

– by serviceability (combinations of actions specified in the expressions (6.14b) – (6.16b), should be used when calculating by Serviceability Limit State).

In SP LIRA 10.12, when choosing normative documents for DCF/DCL, the EN 1990:2002 item was added in the list.

After pressing the «Variable action coefficients according to EN 1990:2002» button, the dialog box appears allowing you to correct/set coefficients ψ for buildings, select between the (6.10) or (6.10а) and (6.10b) formulas for В group (for the А and С group the formula (6.10) is always used), select between the ψ1,1 or ψ2,1 coefficients for emergency design cases, as well as select the tables for basic combinations (for permanent or transitional design cases).

Tables can be selected by marking the appropriate checkboxes, to be able to design structural elements for which geotechnical influences and soil interactions need to be taken into account (it is necessary to use one of three approaches described in the Erocode 0).

When choosing normative documents EN 1990:2002 for DCF/DCL, in loadings are specified:

for permanent – type of impact, coefficients to normative and designed for limit states by bearing capacity for permanent and transitional design cases;

for pre-tensile – type of impact, coefficients to normative and designed for limit states by bearing capacity for permanent and transitional design cases;

for temporary – type of impact, coefficients to normative and designed for limit states by bearing capacity for permanent and transitional design cases, coefficients ψ for buildings;

emergency – type of impact, coefficient to normative;

seismic – type of impact, coefficient to normative;

After performing the calculation, the table of calculation results of the calculated combinations is as follows.

The table provides links to the formulas, on which the calculations were performed, table numbers from Annex А, Eurocode 0, from which the coefficients were taken, and the coefficients with which the load cases were included in the combination.

Sometimes, there are cases when the structure has oscillation forms (modes) with a very close frequency. This will certainly happen if the model has a similar mass and stiffness distribution in different horizontal directions or if two identical constructions in the model have no connection with each other. In addition, there may be many other factors by which the building has a number of close oscillation frequencies.

On the one hand, the total impact from two separate forms is summed up according to some rule – most often it is the square root of a sum of squares or a complete quadratic combination. However, on the other hand, two closely related forms can in reality act as one, and these rules can spoil the more realistic behavior of the structure. Despite the fact that, according to the results of conventional modal analysis, we get different forms with similar frequencies, these forms can be combined in the postprocessor into one, and then receive for it inertial forces, internal forces, and displacements when solving dynamic problems. Starting from SP LIRA 10.12, it became possible to perform this procedure automatically. To do this, in the parameters of the dynamic loading, solved in a modal way (seismic, wind pulsation, impulse action, impact action), mark the «Summarize forms with multiple frequencies» checkbox.

Additionally, in the calculation parameters, you can set the percentage of deviation of the frequency values when summing the forms, when the frequencies are considered multiple.

In the calculation results, we will already be able to analyze the results by one form, since sets of forms with close frequencies will be added. The figure below shows an example of a list of two loadings as a result of the calculation. In the first loading, the summation of multiple frequencies was used, where 1-4, 5-8, 9-12 forms were summed up accordingly into 1, 2, 3 forms. The second loading contains a list by forms without taking into account the summation of multiple frequencies.

Regularly, there is a situation when some parts of the model should be connected to each other, but their elements at the points of contact do not have common nodes. Previously, you had to make resubdividing and stitching of a grid of individual areas or link pairs of nodes through displacement combining or ARB, which led to a very noticeable decrease in the accuracy of the FEM calculation or it took a long time to provide a satisfactory residual.

Starting from the SP LIRA 10.12 version, there is an alternative opportunity to link parts of the model using grids coordination. In other words, a node of one grid is connected to an element of another grid. All types of elements, both linear and non-linear, can be interconnected. Formally, in SP LIRA 10.12, even grids that do not have intersection areas can be connected. In this case, the accuracy of the solution practically coincides with the case when the grid nodes of the array of elements ideally coincide.

The coordination principle is based on the following provisions:

1) From the user-selected array of nodes and elements, those node-element pairs are searched, which are closest to each other.

2) Knowing a pair of node-element, a point is searched on the element (fictitious element node), which is closest to the node. A displacement unification along user-selected degrees of freedom is imposed between this point and the node. In the FEM calculation, the results at a given point are approximated with the results of the element nodes.

To perform coordination of grids, a node must be specified and the element to which the node is binded. If the nodes fit exactly into the elements, then the program can automatically generate a connection of arrays of nodes/elements. The degrees of freedom are also set, according to which there is a coordination: 3 linear directions, 3 angular directions, warping, temperature, filtration. Along the unselected directions of displacement, the node-element pair will act as an ideal hinge.

When coordination is assigned, the couplings are visualized. Even grids that do not have intersection points can be linked by the selected degrees of freedom. The following figure shows examples.

The picture below shows a comparison of the two components: on the left – a gris with solids, fully connected regular, on the right – the component is connected from two separate arrays of solid regular grids. The results show that in the bond zone there are no bright peaks of stress concentrations, which indicates a good matching accuracy with a reasonable use of this method.

In another example, we compare two models of a T-shaped joint by displacements from the applied uniform pressure on the wall: in one the grid is regular, in the second the coupling consists of two separate plates with a radically different grid, and grids coordination is used. The displacements show that the results are very close, which also speaks of the satisfactory use of the function of coordination.

When calculating for dynamic effects, a number of regulatory documents recommend taking into account the effects of random torsion of the building due to the uncertainty of the mass distribution in a real operating structure.

In SP LIRA 10.12 it is possible to take into account these effects when calculating dynamic problems solved by the modal method (seismic, wind pulsation, harmonic action, impulse action, impact action) and direct integration in Dynamics+. For each set of elements (floors) selected by the user, its own random mass eccentricities can be assigned for each horizontal direction. Also, random mass eccentricities can be assigned to the entire model as a whole.

In SP LIRA 10.12, to assign random mass eccentricities to the selected floors, these floor groups must be created in the «Groups of Elements» tab. Groups of elements for each floor can be created manually. And there is also the possibility of automatic generation by selected elements with the entering of the minimum height between overlaps.

In order to assign random mass eccentricities, you need to open the parameters of dynamic loading and mark the «Mass eccentricity consideration» checkbox. Then the value of eccentricities for horizontal directions X, Y for the selected floors or for the entire model as a whole can be entered by clicking the «Edit…» button.

After solving the dynamic problem for each user-selected dynamic load, you can see results for the created groups of floors (masses, centers of stiffness, centers of mass) in the «Load Analysis» tab.

The figure below on the left shows a comparative example of the results of displacements of a certain building, taking into account the random mass eccentricities, and on the right – without taking them into account. As you can see, for the form with the maximum contribution of the modal mass, the effect of torsion became clearly visible.

There is also some difference in the results of modal analysis. Below you can also see a comparison table for the given building.

In order to increase the rigidity of the structure, reduce its weight or for ergonomic reasons, hollow slabs, ribbed slabs, wavy profile elements etc. are commonly used in construction. Such elements cannot be called shells, but if their profile has a certain periodicity, then the mass and stiffness properties of such elements with a certain accuracy can be averaged and taken in the calculation as plates.

In the version of SP LIRA 10.10, for this kind of tasks it became possible to use the stiffness reduction coefficients, when the stiffnesses of a certain periodic profile could be calculated manually and the stiffness of the plate could be brought to these values. Starting from SP LIRA 10.12, it became possible to use the most common series of ready-made sets of sections of a periodic profile with automatic calculation of reduced stiffnesses. At the moment you can use the following cross sections: T-shaped slab with ribs in one and two directions, cross slab with ribs in one and two directions, box-like slab with ribs in one and two directions, hollow-core slab with circular openings, beam grillage, corrugated profiled flooring, trapezoidal profiled flooring, slab on metal profiled flooring.

In order to use such cross section types, run Cross Sections/Stiffnesses Editor and select the appropriate profile type in the «Plates» tab, and then assign the required dimensions to it. You can also view averaged membrane, bending and shear stiffness matrix of reduced shell, which will be used in the FE calculation.

Reinforcement calculation for periodic profile plates is not directly implemented, but a similar analysis can be carried out using equivalent bars, collecting internal forces from the selected plates of a special cross section and calculating the reinforcement for them.

Avalanche choice was implemented in order to select nodes and elements of a connected surface according to the criterion of the angle between adjacent faces (for plates and solids) or bars (for bars). An approximate algorithm for this choice is shown in the figure below. Initially, you should select one item. At the first iteration, the program searches for all elements that have a common node (for bars) or a common edge (for plates and solids). If the angle between the selected element and its «neighbors» is less than the specified one, then the adjacent element fits into the selected array. At the second iteration, we check by this condition the elements that were added to the selected ones at the last iteration, etc. If at some iteration no elements have been added to the selected array, then the execution of the algorithm stops.

This principle significantly speeds up the work with the selection of arrays of elements. So, for example, in one click you can select a foundation slab by referring to only one of its elements. The possibility to set the maximum fillet angle allows you to select complex surfaces. A prime example would be the choice of a tubular joint nozzle.

For solid elements, elements belonging to the surface are selected. In this case, only those nodes that lie on this surface are selected, and not all nodes that belong to the selected elements. Such selection, for example, can be useful for assigning loads to the face of a solid element, for generation of equivalent shells, etc.

On the «Avalanche choice» tab, you can select an element by index (for solid element, specify the number of face) and click the «Select» button, or just click on the desired element on the model itself. For avalanche choice of bars and plates, the ban on branching can be set – if more than three elements have a common node (for bars) or a face (for plates), then such elements will not be considered as «adjacent». The fillet angle is the angle by which one element deviates from the plane of an adjacent element. There is a checkbox helping us (when it marked) to select the nodes on the surface. In the «Mark outside flange» checkbox is marked, then all plates in the selected array, that have an edge which does not belong to other elements, will be selected. If at the same time the «Mark nodes» checkbox is marked, then the nodes along free edges will also be selected.

Plate of inelastic lonk allows you to simulate the nonlinear behavior of joints. Linear and nonlinear joint behavior can be specified in three longitudinal and three rotational directions. The length of the element along the orthotropy axis Y is considered equal to one meterThe plate can be used in all types of static and dynamic analysis with nonlinearity.

Dialog box elements

The dialog box allowing to specihy stiffness setting is shown in Fig. 2.

Area 1

Name and description

* Name — field containing cross section's name. By default, it is set by program. The name is displayed in the table of cross sections and serves to identify the cross section. Or you can enter the name manually. For this purpose, uncheck the corresponding checkbox and enter the new name.

* Description — field that contains cross section's description, which will be displayed in the table of stiffnesses of elements. It is optional and used for cross section identification.

Area 2

Relative stiffness of link under tension-compression along global axes.

If the «Rx elastic », «Ry elastic » and «Rz elastic » checkboxes are marked, enter the values to the input fields below them.

If these checkboxes are cleared, set the required parameters of the "reaction-deformation" graph in the tables below.

Area 3

Relative stiffness of link under rotation around global axes.

If the «Rux elastic», «Ruy elastic» and «Ruz elastic» checkboxes are marked, enter the values to the input fields below them.

If these checkboxes are cleared, set the required parameters of the "reaction-deformation" graph in the tables below.

In the process of analyzing and documenting the calculation results of a non-standard object, it may be necessary to display and document isofields or calculated data diagrams, which are not yet implemented in the program, but which are not difficult to obtain by calculation, relying on already implemented data. Exactly for such cases the «User Results» mode has been implements in SP LIRA 10.12.

The mode consists of 3 logical parts:

Block for setting and editing scripts.

To set a script, you need to select which objects it will work with (nodes, bars, plates, solid or special FE), specify unit settings, which will be used in calculations, and also set the script itself (in the text editing window) using the C# programming language.

The script can use standard mathematical methods as well as additional methods, allowing to use in calculations the properties of nodes or elements and calculation results available in SP LIRA. The composition of additional methods depends on which objects the script will work with.

* For nodes available:

o node number

o coordinates

o value of displacements from load or DCL

o value of reactions in links from loading or DCL

o values of inertial forces for dynamic loadings

o temperature value for problems of the «Thermal conductivity» system

* For bars available:

o element number

o available coordinates of element’s center of gravity

o numbers of assigned cross section and material

o physical properties of the material

o geometric characteristics of the section

o value of internal forces from loading or DCL

o value of temperature and temperature flow density for problems of the «Thermal conductivity» system

* For plates available:

o element number, numbers of nodes in the element

o coordinates of element’s center of gravity

o numbers of assigned cross section and material

o physical properties of the material

o section thickness

o value of internal forces from loading or DCL

o value of principal stresses and strains (in the upper, middle and lower layers) from loading or DCL

o value of temperature and temperature flow density for problems of the «Thermal conductivity» system

* For solid elements:

o element number, numbers of nodes in the element

o coordinates of element’s center of gravity

o numbers of assigned cross section and material

o physical properties of the material

o value of internal forces available from loading or DCL

o value of principal stresses and strains from loading or DCL

o value of temperature and temperature flow density for problems of the «Thermal conductivity» system

* For special finite elements available:

o element number, numbers of nodes in the element

o coordinates of element’s center of gravity

o numbers of assigned cross section and material

o value of reactions от загружения from loading or DCL

Block of visualization of graphs with iteration of steps or time points

Node or element numbers, as well as the script for calculating the corresponding graph coordinate are specified separately for abscissa and ordinate axes. The graph is obtained as a result of iteration of the steps of nonlinear loading or time points for problems of the «Dynamics+» system.

Block of visualization of graphs by nodes and elements

When plotting a graph, the ordinate axis shows the values obtained as a result of a given script for a given set of nodes or elements. And on the abscissa axis the specified coordinates of nodes or elements are plotted in accordance with the specified sorting.

In the previous versions of SP LIRA 10, the possibility to directly perform nonlinear calculations of bar elements with cross sections from rolled metal products was absent. It was only possible to replace the section of the rolled steel with a suitable parametric section with approximate parameters and perform the calculation.

In SP LIRA 10.12, it became possible to carry out nonlinear calculations for bar elements with metal sections without conversion to parametric, which allows you to significantly reduce the time for preparing the design model.

Rolled steel sections can be assigned to the following physically nonlinear bar finite elements: 204, 210, 410, 504, 510.

For the calculation, the following laws of nonlinear material can be used: 11, 13, and 14.

Before calculation, automatic triangulation of the metal cross section is performed. In this case, for the resulting grid of cross section elements, the flat cross section hypothesis is fulfilled. The stiffness matrix of a physically nonlinear finite element is formed on the basis of variable integral stiffnesses, calculated at the points of integration of the finite element at each step of the solving.

After calculation, in addition to displacements and forces, stresses are also available in steps in each element of cross section.

Modern normative documents governing the calculation of buildings and structures in conjunction with a soil foundation, often require taking into account that the deformations of the base and structures at their contact may be incompatible. In the calculations, it is necessary to take into account the possibility of detachment or shear on the contact "structure - soil".

To simulate the work of soil in areas of contact with enclosing structures, special interface (contact) FE (268, 269) have been implemented in the SP LIRA 10.12. For solving plane problems, a rectangular contact FE (268) has been implemented. And for solving spatial problems, spatial triangular and quadrangular prisms (269) have been implemented.

To describe the parameters of deformation of interface elements, except for the parameters describing the operation of the adjacent soil element, the virtual thickness of the interface is set (along the Z1 axis) – Hf, as well as interface durability Riner (in the range 0 - 1).

The figure shows how, using the interface elements (gray), it is possible to interconnect both soil elements (brown) and structures (blue). When using 3-node/4-node soil elements, corresponding interface elements are defined by two pairs of nodes. While 6-node/8-node soil elements correspond to interface elements defined by three pairs of nodes. The figure shows the interface elements as having a certain (real) thickness. However, this thickness does not affect the work of the interface elements (the value Hf is taken into account) and can be very small. In this case, the local X1 axis (green) must be parallel to the edge of the adjacent structural element.

During the implementation, the theory outlined in the following tutorial has been used: *Fadeev A. B. «Finite elements method in geomechanics.» – M.: Nedra, 1987, p.168 – 174*.

In the SP LIRA 10.12, table editing of the following model parameters have been implemented:

* coordinates and node restraints;

* topology and properties of finite elements (FE);

* geometry and properties of architectural elements (AE);

* elastic foundation parameters of bars and plates for FE and AE.

You can find the «Table Editing» mode in the «Model» menu or on the «Add Fragment» toolbar, or on the «Add» tab of the ribbon.

In the «Table Editing» window, you can create new nodes in the «Nodes: coordinates» area. To do that, enter the coordinate values and restraints directions or insert tabular data from other sources. In this case, the numbering of new nodes is performed automatically.

For FE and AE, only editing of already existing elements is available. If the «Edit specified ones» checkbox is not marked, then you should indicate the element number to make edits. If this checkbox is marked, then a table with already specified parameters will appear and you should make changes directly to this table.

After making changes in the table, press the «Apply» button.

When solving the problems considering warping of bars, to determine stresses at all points of the section, you need to know the components of the moment of pure (free) torsion Mxt, sometimes called Saint Venants' torque moment, and the bending torsion moment (flexural-torsional moment) Mxw. These are the components into which the total external torsional moment Mx = Mxt + Mxw can be decomposed. The bending torsion moment and the moment of pure torsion are found analytically from the dependencies:

Starting from SP LIRA 10.12 version, it became possible to obtain diagrams of these torsion components Mxt and Mxw for bars considering warping (7 FE type). The corresponding diagrams can be displayed in the results for bars.

The figure below shows an example of comparing the calculation in the program and analytical solution of a cantilever exposed to torsion with bending. According to the conditions of the problem, the length of the rod L = 2 m, height of channel shelves H = 12.5 cm, channel width B = 19 cm, cross section thickness 1 cm. Modulus of elasticity of the material E = 2?1011 Pa, Poisson's ratio 0.25. Load Р = 1 kN, applied to the corner of the channel, creates a torque Mx= 95 Nm. It’s needed to find the components of the torsional moments Mxt and Mxw.

An analytical solution to a similar problem is given in the following source: [Birger I. A., Mavlutov P. P. Strength of Materials: Tutorial. — M.: Science. Main. Ed. of Phys.–Math. lit., 1986. — 560 p., pp. 357-358].

When solving the problem in SP LIRA 10.12, the bar was split into 5 elements, 5 intermediate cross sections were used. We received the following diagrams of the components of the torsional moment:

Below is a table comparing the results obtained analytically and in SP LIRA 10.12 at 6 points of the bar. These results are almost the same. This indicates the correctness of solving this type of problems using SP LIRA 10.12

Numerical methods are becoming increasingly popular for modeling complex and diverse processes of heat transfer and convective heat transfer. The advantages of numerical methods are that they allow to obtain the desired result, taking into account the real properties of materials and the geometry of all bodies included in the computational space. One of such methods is the finite element method, used to solve partial differential equations arising in solving problems of applied physics.

In matrix form, the unsteady-state heat equation is written in the form

where [*K*] – positive definite symmetric matrix of thermal conductivity coefficients, or just a heat conduction matrix, [*C*] – specific heat matrix, {*T*} і {*F*} – temperature vector and right side vector, respectively.

SP LIRA 10 uses an implicit integration scheme

where *Δτ* – time step (sampling rate), *T _{i}*,

*T*– temperature vectors at the current and next time moments,

_{i+1}*F*– the vector of the right side at the current time.

_{i}When specifying the initial data, four new types of problems are implemented:

1. Linear problem with unsteady-state thermal conduction and time-dependent dynamics

2. Linear assemblage problem with unsteady-state thermal conduction and time-dependent dynamics

3. Nonlinear problem with unsteady-state thermal conduction and time-dependent dynamics

4. Nonlinear assemblage problem with unsteady-state thermal conduction and time-dependent dynamics

Expanded the list of loads in the loadings of «Time-dependent dynamics» «Dynamic load (nodal forces)»:

Specified temperature in the node with uniform step,

Specified temperature in the node with arbitrary step,

Concentrated heat flow with uniform step,

Concentrated heat flow with arbitrary step,

Ambient temperature with uniform step,

Ambient temperature with arbitrary step,

and «Dynamic load (right-hand side)»:

added all loads of stationary thermal conductivity, except for the specified temperature in the node.

In the calculation results for unsteady-state thermal conduction, you can view the change in temperature in the nodes and elements, the change in the heat flow by projections, both at a selected moment in time, and in the form of a graph over the entire time range.

The possibility of dynamic input for specifying architectural elements has been added into SP LIRA 10.12.

When hovering over a node of design model, the «Dynamic input» dialog window appears with the coordinates X, Y, Z (fig. 1) and length L (fig. 2), where you can enter the necessary values to create the element.

To switch between input of coordinates and input of length, you need to press PageUp/PageDown on the keyboard or up/down arrow. And to move between coordinate values, use the Tab key. After setting the parameters, confirm the entry pressing the Enter key.

## Reinforced concrete structures

Calculation of round and rectangular S/R/C cross sections are implemented. The dimensions of S/R/C cross section are determined parametrically or according to a given external profile. As an external profile of S/R/C cross section, round and rectangular can be used.

For cross sections without external steel profile, crack resistance tests are implemented.

Implemented types of S/R/C cross sections with rigid reinforcement:

All types are available for specifying, both with and without external steel profile.

Now you can specify various classes and types of reinforcement in cross sections of bars and plates of elements for SP 63.13330.2012 (SNIP 52-01-2003), SP 295.1325800.2017, and SP 63.13330.2018. For each class and types of reinforcement, it’s possible to set individual structural design factors.

The connection between the reinforcement specified in structural design and reinforcement inclusions specified in the section occurs through the material indices of the longitudinal reinforcement.

## Wooden structures

In SP LIRA 10.12, an editable database of wooden materials has been added (fig. 1). Implemented the following types of materials used for wooden bar elements:

* coniferous, laminated wood, LVL, coniferous varietal wood (SP 64.13330.2017);

* coniferous, deciduous, laminated wood, LVL, plywood, OSB, cement particle board (CPB) (DBN В.2.6-161:2017);

* coniferous varietal wood (SNiP II-25-80).

Fig. 1

In the SP LIRA 10.12 version, the calculation of wooden bar elements has been implemented in accordance with the norms of SP 64.13330.2017, EN 1994-1-1, DBN V.2.6-161:2017 and SNiP II-25-80.

The calculation and designing of wooden bar elements are performed for the following cross sections:

* solid – rectangular and round cross sections (SP 64.13330.2017, SNiP II-25-80, EN 1994-1-1 and DBN V.2.6-161:2017 (fig. 1));

* composite – box and I-beam cross sections (EN 1994-1-1 and DBN V.2.6-161:2017 (fig. 2, fig. 3)).

The tests of wooden bar elements on strength by normal stresses, tangential stresses and on overall stability have been implemented. The basic check by normal stresses for compressed, bent elements and elements that work on skew bending, are made according to the formulas of skew bending. The check differs depending on the value of the reduced flexibility.

Identical situation exists with the calculation of tensile elements that are subject to skew bending. The strength of the elements where tension is present, are checked by the following formulas:

Fig. 1 shows an example of calculation of bar element with cross section in the form of a beam according to DBN V.2.6-161:2017.

For comparison, fig. 2 shows an example of the calculation of an identical bar element according to SP 64.13330.2017.

The check on overall stability according to norms of EN 1994-1-1 and DBN V.2.6-161:2017 is performed for compressed elements upon flexural, flexural-torsional buckling mode, for compressed-bent and bending elements – upon plane bending mode.

According to the same principle, the calculation is carried out for normal stresses for bar elements according to the norms of SP 64.13330.2017 and SNiP II-25-80. The calculation of eccentric tensioned and tensioned-bent elements by normal stresses should be performed according to the formula:

The calculation on strength by normal stresses of eccentric compressed and compressed-bent elements is performed according to the formula:

The calculation and stability check according to the standards of SP 64.13330.2017 and SNiP II-25-80 have been implemented. The principle of the universal formula is preserved, since at zero values of one of the types of internal forces, verification is carried out only according to the second term of the formula. So, in the absence of bending internal forces, the test on overall stability is performed exclusively by flexural mode, and at zero values of compressive internal forces performed according to the formula of flat form of bending:

A similar check is performed according to DBN V.2.6-161:2017 and ЕN 1994-1-1:

Fig. 3 illustrates the column of calculation results, in particular the mechanical characteristics of materials. In this example, coniferous wood is considered, wood class – C20.

## Soils

Eurocode 7 has no uniform approach to defining the settlement of foundations. To determine the values of the foundation settlement, general requirements and recommendations are given. The choice of the method for calculating the settlement and the allowable values is left at the discretion of the designer or national rule-making authority. The use of specific methods is specified in the National Annexes to Eurocode 7. In the SP LIRA 10.12 version, the following standards are implemented: EN 1997-1:2004 and SN RK EN 1997-1:2004/2011 (NTP RK 07-01.4-2012).

Total instant foundation settlement is determined (according to DIN 4019) using the calculation method based on the elastic half-space model with conditional restriction of compressible layer (layer-by-layer summation method) by the formula:

Vertical soil stresses ?z at a depth z are calculated based on the Boussinesq approximation and the principle of superposition.

The calculation takes into account additional stresses caused by the load on the foundation, up to the depth of the compressible layer Hc. In accordance with EN 1997-1:2004, Hc is taken from the condition that the effective stresses from the foundation are 20% of the stresses from the dead load of the soil. The ratio can be adjusted by the user through the coefficient of depth of the compressible layer in the «General» tab.

Consolidation settlement by the standards of SN RK EN 1997-1: 2004/2011 (Annex D, NTP RK 07-01.4-2012):

The program allows you to take into account the impact of consolidation during the calculations. To do this, you must specify the following consolidation parameters: duration of applied load t and filtration coefficients kф for soil layers

Fig. 1. Specifying the duration of load Pz applied on the base of the foundation in the «Settlement Consolidation Calculation Options»

Fig. 2. Filtration coefficients kф in the «Soil Characteristics» table

The consolidation settlement for the time t is determined by the formula:

Consolidation settlement by the standards of EN 1997-1:2004:

The calculation is performed after checking the appropriate box and filling in the consolidation parameters: duration of construction tс, duration of action t of operational loads Pz, filtration coefficient kф.

Fig. 3. Specifying the duration of construction and operation of construction objects in the «Settlement Consolidation Calculation Options»

The program defines the boundaries of the consolidated soil layer and the direction of water filtration from this layer (up, down, in both directions). If the outflow occurs in one direction, the trajectory of the outflow of water is equal to the thickness of the consolidated layer, in case the outflow occurs in two directions – half of the layer thickness.

The calculation of consolidation is influenced by time factors that depend on the outflow trajectory.

The program allows you to create a graph of the consolidation settlement over time, which makes it possible to assess the development of the settlement of water-saturated soils in time, as well as its stabilization.

Fig. 4. The graph of the consolidation settlement for the foundation slab element

The method of calculating the settlement of a single piles in SP LIRA 10.12 is based on the use of the linear elastic method of Poulos and Davis, described in the book Pile Foundations Analysis and Design (H. G. Poulos et. E. H. Davis, 1980). With this method, the foundation soil is described by the modulus of elasticity E and Poisson's ratio ?. The settlement of a single pile is determined using a set of correction factors.

The following assumptions were made in the calculation:

1) pile and soil are initially stress free;

2) there are no residual stresses in the pile resulting from its installation;

3) the displacements of the pile and adjacent soil are equal.

The settlement of a single piles from the action of axial load Pz is determined by the formula:

Using the settlement influence factor I, the program adjusts the following parameters:

for piles on a rigid base (standing piles):

the influence of pile toe bulb settlement (depends on the length of the pile and the sizes of the pile shaft and toe bulb);

pile compressibility (depends on the stiffness coefficient of the pile and the ratio of the length to the diameter of the pile);

rigidity of the bearing layer (depends on the ratio of the elastic moduli of the pile and the secant modulus of soil deformation under the pile, as well as on the ratio of the surrounding soil to the stiffness coefficient of the pile – for different ratios of pile length and diameter);

the influence of reduction Poisson's ratio ? in the soil surrounding the pile to decrease the value of the pile settlement at a constant modulus of elasticity of the soil (depends on the Poisson's ratio of the surrounding soil and the stiffness factors of the pile).

for friction pile:

the influence of pile toe bulb settlement;

pile compressibility;

influence of incompressible soil under the pile toe bulb (depends on the ratio of the pile length to the pile diameter and the ratio of the pile length to the thickness of the compressible layer above the incompressible layer);

the influence of reduction Poisson's ratio ? of the soil.

Calculation of piles according to the norms of EN 1997-1:2004 is performed in the «Cross Sections/Stiffnesses» Editor and «Soil» Editor. Their modeling is possible both with a finite element 57 and with a chain of bars of equivalent stiffness.

a)

b)

Fig. 1 Setting the norms and parameters for calculating a single pile according to EN 1997-1:2004:

b) in the «Cross Sections» Editor; b) in the «Soil» Editor

The result of the calculation is the settlement value s and the relative stiffness of the pile Rz (along the global z-axis).

a)

b)

Fig. 2. Results of calculating a single pile according to the norms of EN 1997-1:2004

a) in the «Cross Sections» Editor; b) in the «Soil» Editor

The calculation of design soil resistance of foundation is one of the most important calculations of buildings and structures by Serviceability Limit State. Key prerequisite for the application of settlement calculation methods, based on the use of the provisions of the theory of linear soil deformation, lies in the fact that the average pressure under the base of foundation should not exceed the design soil resistance of foundation: Pz?R. For preliminary calculations, the value of R is used in determining the dimensions of the foundation.

In the SP LIRA 10.12 version, in order to determine the value of R, the provisions of the following regulatory documents have been implemented: SNiP 2.02.02-83*, SP 50-101-2004, SP 22.13330.2011, SP 22.13330.2016, DBN V.2.1-10-2009, where the formula is given:

Despite a number of assumptions in this formula, the determination of the parameter of design soil resistance R of the foundation is mandatory when designing shallow foundations. Taking into account the accepted coefficients, the formula can be used for designing almost any shallow foundations.

Fig. 1. Creating a plate foundation to calculate design soil resistance

In the SP LIRA 10.12, in order to calculate the design soil resistance of the foundation, it is necessary to combine the elements of the foundation into a group (see fig. 1), set the design parameters of the foundation, and also specify average pressure Pz under the foundation base for transferring to the «Soil» Editor for calculation. Subsequently, you can clarify the utilization coefficient on design soil resistance according to the results of the obtained average pressure under the foundation base.

Fig. 2. Calculation results of design resistance of foundation soils in the «Soil» Editor

Based on the results of calculation of the soil foundation in the «Soil» Editor, the possibility to perform a comparative element-by-element analysis of design soil resistance R and average pressure Pz under the foundation base is provided (see fig. 2).

a)

b)

Fig. 3. Model analysis: a) design resistance R of the foundation soils; б) utilization coefficient on R

In the SP LIRA 10.12, assessment of soil conditions of the construction site, as well as stresses under the base of foundation of the model of the construction object is carried out in the «Model Analysis» mode. Calculation results are visualized as mosaics of design resistance R of the foundation soils and utilization coefficients on R (see fig. 3).

One of the most important factors in the design of bases and foundations is the strength of the underlying layers of the base Rz. In the SP LIRA 10.12 version, in order to determine the value of Rz, the provisions of the following normative documents have been implemented: SNiP 2.02.02-83*, SP 50-101-2004, SP 22.13330.2011, SP 22.13330.2016, DBN V.2.1-10-2009. Checking the underlying layers of the base is a development of checking the strength of the bearing layer of the soil. If under the bearing layer, within the limits of the compressible layer, at some depth z, less firm soil lies, then the stress transmitted to the roof of the underlying soil layer is checked by the condition:

Calculation of the strength of the underlying layer is performed in the «Soil» Editor. If the condition of strength of the underlying layers of the soil is not met, the program displays a message with a list of elements, under which the strength of the soil foundation is insufficient:

Fig. 1. Message about insufficient strength of the underlying layer in the SP LIRA 10.12

If successful, analysis of the calculation results of the strength of the underlying layer is performed in the «Soil» Editor, in the «Calculation Results» area. The «Design resistance» tab is designed to analyze the ratio between the design resistance of the underlying layer Rz at a depth z from the foundation base and total soil pressure ?z in this layer.

Fig. 2. Calculation result analysis of the strength of the underlying layer in the «Soil» Editor

## Metal Constructions

In the SP LIRA 10.12, the possibility to calculate trussed three-branch cross sections as a single bar element has appeared. Calculations are performed both in proportioning mode and in check mode by Ultimate Limit State and by Serviceability Limit State in accordance with the current building codes of the SP 16.13330.2017 (Russia), DBN V.2.6-198:2014 (Ukraine), as well as SNiP II-23-81*, which is still valid in some countries of the former Soviet Union.

Unlike two-branch sections, all three branches of such a section are taken from one profile, form a regular triangle and are oriented by the main axes symmetrically relatively to the center of the section. It is assumed that the local Yв axis of each branch is directed tangentially to the circle, passing through the centers of gravity of the branches (circular direction). The local Zв of each branch is directed from the center of the section outward (radial direction).

Fig. 1. General view of a three-branch cross section

The connecting elements can be geometrically fixed lattice, or strips. All three planes of the connecting elements are assumed to be the same both in terms of the type of connecting elements and in the outline of the lattice and their sections. (The picture of the lattice, when viewed from the outside, is the same for all three verges.)

The program offers a wide range of three-branch cross sections with different branch profiles, lattice types and strips. Many of these cross sections are little described in the literature, but have proven themselves well in design and construction. They are quite rigid, economical due to the reduction in the number of branches and verges of the lattice in comparison with four-branch ones; they do not need additional stiffness diaphragms. Three-branch cross sections work well in torsion, and our program can calculate such elements taking into account torsion.

Fig. 2. Types of three-branch cross sections

It should be noted that the section of the Y (SP) type with branches from bevelled angles is not included in this release because of lack of technical normals that determine the dimensions of angles after bevelling, and, accordingly, because of lack of their geometric characteristics. However, such sections are depicted in the current standards of SP, DBN, SNiP, as well as in the EN 1993-3-1:2006, section 1.7 (schifflerized angle). Thus, at present we have already decided on the solution of these issues, found all the geometric characteristics of the bevelled corners, and such sections will appear in the SP LIRA soon.

Fig. 3. Types of connecting elements

Fig. 4. Example of three-branch cross sections with branches from channel bars and connecting elements in the form of a lattice made of angles and in the form of strips made of channel bars

Cross section setting:

Fig. 5. Setting of three-branch cross section in the Cross Sections Editor

Specify geometric dimensions and profiles included in the three-branch cross section in the Cross Sections Editor. In addition, select the type (lattice or strips) and the type of lattice by outline.

It should be noted that here, as in two-branch sections, the steel for the branches is specified in the Materials Editor and is assigned in the traditional way, through the «assignment cross sections, materials and structural design parameters to the elements». Steel for connecting elements is assigned when specifying the cross section directly in the Cross Sections Editor. With this method, it is possible to specify different steel types for branches and for connecting elements.

Fig. 6. Specifying three-branch cross section

Structural design setting:

Fig. 7. Specifying structural design of three-branch cross section

Here, as for any structure, general indicators are set – class of the structure by the type of stress-strain behavior, factor of safety by responsibility of the structure. After that, you need to set the main parameters for calculating by Ultimate Limit State and by Serviceability Limit State both for the entire element, as a single bar, and for individual elements that make up this cross section – for branches, for bracings and struts, for strips. These are indicators such as conditions of use factors, effective lengths and critical slenderness in the main directions and others.

Calculation results:

For each element (or structural element) of a three-branch cross section, up to four lines are displayed, displaying the results of various checks.

For three-branch cross section with with lattice:

line 1 – results of various checks of the element as a single bar;

line 2 – results of various checks of branches;

line 3 – results of various checks of lattice braces;

line 4 – results of various checks of struts (racks) of lattice, if a lattice scheme with struts is selected.

For three-branch cross section with strips:

line 1 – results of various checks of the element as a single bar;

line 2 – results of various checks of branches;

line 3 – results of various checks of strips.

Fig. 8. Calculation results of three-branch cross section

2

An utility for calculating steel deck has appeared in the SP LIRA 10.12.

The work of a thin plate, supported by hinges or rigidly embedded on both sides, is considered. Supports are assumed to be linearly fixed in both directions. It is this scheme of work that is proposed in all educational and reference literature on building steel structures. The calculation gives a sufficiently accurate result also for a plate supported on four sides with a ratio of sides at least 3 for a freely supported plate and at least 2 for a plate with clamped sides. The load is assumed to be evenly distributed over the area and causes bending from moment and tension from expansion in the plate. The utility can be used for calculating the flat steel deck of running platforms, for calculating the bunker sheathing with flat walls, coverings under hydrostatic pressure, etc.

Fig. 1. Flooring work scheme

The calculation is made according to the S.P. Timoshenko’s book «Strength of materials», volume 2, Publishing House «Science», Moscow, 1965 y. In the educational and reference literature approximate solutions of this issue are presented, displayed in the form of graphs, tables, approximate formulas. Our program uses the exact solution of the equations (77), p. 72 and (79), p. 73 from the above mentioned source, proposed by Candidate of Phys.-Math. Sciences Kukanov N.I. (Ulyanovsk State Technical University).

The maximum permissible deflection of the flooring is taken by default according to p. 2 of the table of maximum deflections in the current standards for loads and impacts (SP 20.13330.2016, DBN V.1.2-2:2006, SNiP 2.01.07-85), but the user can set his own value both in millimeters and in fractions of a span.

Fig. 2. Deck calculation result in the test mode for hinged and rigid support

The utility works both in check mode and in proportioning mode and has a convenient and intuitive interface. Using SP LIRA settings, you can choose convenient units, as well as convenient interface language (Russian, Ukrainian, English). Fill in the required fields – calculate – get the result!

## Import and export

DWG format (from the word Drawing) is a binary file format that is used for storing two-dimensional (2D) and three-dimensional (3D) models when working with CAD systems such as AutoCAD, Advance Steel, CorelCAD, BricsCAD, etc. In SP LIRA 10.12, the possibility to import/export models from this format has appeared.

* The plugin allows import/export between SP LIRA 10 and Advane Steel. It’s implemented for Advance Steel 2020 and Advance Steel 2021.

* The LIRA 10 tab with the buttons for import and export of the model and the button that runs synchronization of databases of rolled steel cross sections has been added to the main Advance Steel ribbon.

*

* Import and export is implemented for the main structural types of elements that are stored in DWG-format files, as well as their cross sections and materials.

* Synchronization form of steel section database allows to import and export tables to AstorProfiles database. It’s implemented for AstorProfiles 2020 and AstorProfiles 2021. Supports import, export, replacement, and merging of the tables.

* The plugin allowing to export BIM-model from Renga to SP LIRA 10 is implemented for the current version of Renga.

* The button for exporting a model to a FEP file has been added to the main program panel.

* Created a form with information about the progress of the export process. Export is carried out for basic structural element types.

1. Implemented export of MC check results. The displayed results are configured through the "tree" of checks. Results are displayed as diagrams of bar analytical elements.

2. Added the possibility to consider reinforcing meshes, set on plate elements Autodesk Revit. To do this, mark the “Сonsider installed reinforcement” checkbox. When the checkbox is marked, selection of reinforcement inclusions is disabled and the total longitudinal reinforcement is used to create the mosaic.

3. Implemented the assignment of dead load by materials. List of materials, loadings, and coefficients of dead load can be specified in the “Import Wizard” form by clicking the "Settings" button in the "Dead load" block.

4. Properties of Autodesk Revit analytic elements have been expanded. This allows you to import column elements as piles. Now you can specify the application of the surface loads not attached to an element. And indicate whether ARBs will be created during triangulation.

5. UI of results export has been revised. Separate dialog form was replaced with a pop-up interface element, which allows you to customize and display the results faster. The results are loaded once – by pressing the “Update” button.

6. Implemented export of punching shear calculation results as a punching shear contour and fitted transverse reinforcement.

7. Displaying hinges on a Autodesk Revit 3D model.

8. Added the generation of reinforcing meshes in plate elements according to the results of reinforcement proportioning. You can adjust the position of the generated reinforcing meshes using the following parameters:

* Background reinforcement – defines the minimum value of fitted reinforcement for which the installation of additional reinforcement element is needed.

* Maximum distance between nodes (of the finite element model) – determines the distance at which finite element results will be grouped for constructing reinforcement elements.

* Minimum reinforcement area – allows you to restrict the generation of reinforcing elements for small areas.

Graphics part and computational processor

1 In the scale for results of the same type, the synchronization of used visualization types has been added

2 For result values without units of measure, the ability to adjust the number of decimal places has been added

3 For the "Combinations" mode when displaying extreme values of factors, numbers of loadings and combinations have been added

4 Improved performance of modal analysis for loadings with the same mass distribution

5 Implemented work with architectural elements in the ASSEMBLAGE system

6 Property "Ignoring the stability of elements" has been added for architectural elements

7 The elements of shielding layer have been implemented in filtration (FE178, FE172-174)

8 Added the possibility to manage the parameters of nonlinear loadings in the DYNAMICS+ problems

9 In the "Add element" mode, the function of rounding intersecting elements has been implemented

10 Added calculation of the mass center in the problems with time-dependent dynamics

11 Dimension lines that are not binded to the nodes of design model have been implemented

12 Added a check for repeatability of architectural elements in the "Model Control" mode

13 Implemented commands for selection by cross section - material - structural design

14 Added the possibility to use Del and Esc buttons, when assigning hot keys

15 Added selection of bars orientation in the load on the design model applied to the bars

16 Conversion of loads on the model to nodes/elements without running the calculation has been implemented

17 Added the possibility to manage the objects of cursor sticking

18 In the "Local axes of plates" mode, the ability to co-direct the Z1 axes to a point has been implemented

19 Added a table of initial data for architectural elements

20 In the function of table printing, the printing of cells with pictures and cells with several lines have been implemented

21 Added model export from command line for any available format

22 Rendering when zooming with the mouse wheel has been accelerated

23 Display of the diagram of perimeters of bar element cross sections has been implemented

24 In the "Add node" mode, now you can add the circle center by three points

25 Added saving mosaics to a csv file in the export of results

26 The display of visual attributes for solid FE has been moved to the visible face (previously it was in the geometric center)

27 The size of the model file on disk has been significantly reduced in the problems with a large number of projections and "live" images

28 Displaying mosaics of effective lengths for bar and plate elements has been implemented

29 Consideration of special FE in thermal conductivity and filtration problems has been added

30 In the deformation scaling control, the possibility to adjust visualized deformations in the range from 0 to 2 (default factor is 1) has been added

31 The buttons for fast fragmentation of special elements have been added

32 The buttons for fast fragmentation of equivalent bars and plates have been implemented

33 Information about already assigned restraints of nodes has been added in the restraints mode

34 Creation of model fragments using the tools for moving and rotating the generatrix has been accelerated

35 Saving the splitter position and column width in all editors have been added

36 Accelerated work in the mode of displacements unification groups

37 Implemented ability to disable structural design calculation during batch calculation

Reinforced concrete structures

1 Implemented checks of lightly reinforced cross sections by Ultimate Limit State

Metal constructions

1 Expanded the list of cross sections according to EU standards

Soil

1 Added the possibility to specify and edit boreholes in the SOIL system by coordinates and depth of layers using an Excel table

2 EU standards have been added to the utility calculating the coefficients of subgrade reaction

3 Utility for calculation of single pile has been supplemented with EU regulations

Import / Export

1 In import from 3D DXF, now it is possible to specify additional data on materials / sections / loads in the layer name (similar to importing floor plans from DXF)

2 Added rigid inserts, rigid bodies, displacement unification, and variable bar sections in export for PLAXIS