Following the analysis calculation, the applied reinforcement (longitudinal bars, stirrups etc.) can be designed automatically and refined manually for concrete beams, columns, truss members, slabs, walls and shell elements. The applied reinforcement can be considered in cracked-section analysis.

The table summarizes the available RC design features and its analysis-related effect (cracked-section analysis) by FEM-Design module.

Design element typeDesign feature1585573773672-406.png1585573778330-305.png1585573782915-229.png1585573787911-559.png
1585573768201-924.png  Bar reinforcementAuto design1585573853108-966.png 1585573874778-224.png1585573871212-244.png
Manual design1585573855352-957.png 1585573869887-398.png1585573877455-535.png
Cracked-section analysis1585573863236-877.png 1585573867197-586.png1585573868480-935.png
1585573831073-133.png   Surface reinforcementAuto design1585573879990-961.png1585573864946-861.png 1585573890470-132.png
Manual design1585573878798-454.png1585573866173-113.png 1585573888882-302.png
Cracked-section analysis1585573872383-918.png1585573876182-601.png 1585573887836-729.png
1585573835604-175.png   Punching reinforcementAuto design1585573883841-134.png  1585573886809-630.png
Manual design1585573882511-646.png  1585573873636-923.png
Cracked-section analysis1585573881472-866.png  1585573885212-816.png

Table: RC design features by FEM-Design module

Global Auto (RC) design (Calculate > Design calculations > Auto design all structural elements) gives applied reinforcement for all concrete elements based on their initial design calculation parameters, Auto design > Parameters and optimized to their internal forces and detailed utilization calculations. With Manual design you can fine-tune the reinforcement by elements and/or design groups. You can do quick Auto design by elements and design groups only instead of global design. Of course, any number of design cycles is executable, so the global Auto design can be combined with both previous and additional element-based Auto designs.

No.Global RC designElement-based RC designCombined RC design
11585573949525-261.png  Design calculation parameters1585574004114-884.png  Global Analysis1585573954730-179.png  Design calculation parameters
21585573993155-430.png  Design group1585573952090-625.png  Design calculation parameters1585573997020-936.png  Design group
31585573961573-424.png 1585574043587-844.png  Auto design > Parameters1585573995063-242.png  Design group1585573969423-886.png 1585574038186-531.png  Auto design > Parameters
41585574021361-824.png  Global Auto design1585573963549-317.png 1585574041988-785.png  Auto design > Parameters1585574014808-672.png  Global Auto design
51585574027271-692.png  Manual design by elements1585573971635-353.png 1585573982722-210.png  Auto design by elements1585573967310-807.png 1585574039894-501.png  Auto design > Parameters
61585574049901-913.png  Apply design changes1585574029205-629.png  Manual design by elements1585573965386-714.png 1585573984688-491.png  Auto design by elements
71585574007870-973.png  Global Check1585574051562-444.png  Apply design changes1585574031203-532.png  Manual design by elements
81585574006165-612.png  Cracked-section analysis1585574011057-275.png  Global Check1585574053024-330.png  Apply design changes
91585574058339-646.png  Documentation1585574009620-444.png  Cracked-section analysis1585574016452-368.png  Global Check
10 1585574060429-927.png  Documentation1585574013079-456.png  Cracked-section analysis
11  1585574061999-364.png  Documentation

Table: Recommended steps by design alternatives

Bar Reinforcement

Bar reinforcement design needs internal forces from Analysis calculations applied for Load combinations or Load-groups, 1585574093992-877.png  Buckling length and initial design settings defined by 1585574099922-322.png  Design calculation parameters and 2nd order calculation method by 1585574105384-726.png Configuration.

1585574111041-426.png

Figure: Design calculation parameters

1585574118993-935.png

Figure: Design calculation parameters

The maximal section distance defines the approximate position of the design sections and so the available sections for detailed results.

The method for considering imperfections of bars has to be selected, there are three types:

  • Ignore 2nd order analysis: The internal forces comes from the 1st order results.
  • Consider 2nd order analysis, if available: The internal forces comes from the 2nd order results.
  • 2nd order internal forces + 1st order design: The internal forces comes from the 2nd order results, but the design calculation will be linear.

Auto Design

1585574140289-593.pngGlobal Auto design gives utilization results and suitable reinforcement distribution for all concrete bars of the current project.
light.png

The applied design parameters can be displayed on screen by showing the “RC bar, design parameters” object layer, or click 1585573984688-491.png  Design tool of the 1585573967310-807.png Auto design to show the parameters together with a detailed utilization table. Utilization as colored figure (color palette) can be displayed by selecting New result > RC bar > Utilization, and clicking the Numeric value tool summarizes the list of maximum utilizations by elements in a dialog.

1585574194489-978.png

Figure: Global Auto design and utilization results

1585574210158-767.pngElement-based Auto design finds the most suitable position and distribution of longitudinal bars and stirrups for selected unique or grouped members only according to their user-defined design parameters. Initial reinforcement (steel quality, diameter, profile, concrete cover) and design (aggregate, vibration) settings can be set for the concrete members/groups with the 1585574241422-868.png  Parameters tool of Auto design.

1585574252957-683.png

Figure: Design parameters

To run element-based design for the load combinations or the maximum of load groups, select the required members and/or group with the Auto design command and click 1585574266984-555.png  Design tool. The quick process results applied reinforcement and their checked utilization. Check the Display table box to have a look at the overall design results.

1585574273830-742.png

Figure: Quick summary of Auto design results

The upper table shows the design efficiency and the maximal utilization of the designed single members and groups based on the given design parameters. The bottom table (“Show details”) displays the utilization details of the bar or the members of the group selected in the upper table.

 MeaningNote
1585574282628-966.pngSuitable reinforcement is available 
1585574288796-260.pngSuitable reinforcement is not availableModify bar profile, material or RC design parameters
GroupID of a single bar or a group name 
Design parametersApplied design parameters 
Total weightTotal weight of applied reinforcement 
MaxMax. utilization of a single bar or the significant member of a group 
MinMax. utilization of the less significant group member 
BarID of a single bar or a group member 
SECSection utilizationAccording to Eurocode 2: 6.1
STStirrup utilizationAccording to Eurocode 2: 6.2 and 6.3
CConcrete utilizationAccording to Eurocode 2: 6.2 and 6.3
TUtilization of torsional reinforcementAccording to Eurocode 2: 6.3
CWUtilization for crack widthAccording to Eurocode 2: 7.3

Table: The meaning of symbols, design parameters and utilization results

Quick redesign can be done inside the Utilization table:

  1. Select a bar or a design group in the upper table.
  2. Modify the design parameters of the select element under Parameters.
  3. Click Design.

Applied reinforcement generated by Auto design can be displayed with:

  • Detailed result applied for the displayed utilization result (New result > RC bar > Utilization) of a single bar or a group member.
  • Manual design applied for a single bar or a group member to edit the design reinforcement and/or add further longitudinal bars and stirrups.

Manual Design

1585574376098-805.png

Manual design opens a new window in the current project and gives tools to define new (applied) reinforcement in concrete beams, columns and bars, or to modify/edit the reinforcement generated by Auto design. The drawing area is divided into two view windows:

  • Cross-section
    It shows the cross-section of the current concrete bar. The definition of new longitudinal bars (sectional position) and stirrups (shape) starts in this window. The position of the cross-section (section view) can be set by moving the section marker in 3D view: 
                                                                       1585574451276-123.png
  • 3D view
    It shows the side view of the concrete bar by default. But, any 2D and 3D view can be set with the View menu commands (e.g. general 3D view with View > Space view). The start and end pont (and so the length) of longitudinal bars and the position (the distribution) of the stirrups can be defined here.
  • Interaction surface view / Result window
    In this window 2 types of results can be displayed, Interaction surface view or Summary results. The Ineraction surface shows the section utilization in a graphical way in N-My-Mz coordinate system. By default it is displayed in 3D view, but Horizontal and Vertical cuts can be done.
    The Summary results can be seen also after the bar is Checked.

1585574492335-373.png

1585574497411-900.png

Figure: Working windows of Manual design

You can choose the required window by clicking inside it or its title.

1585574519415-230.png

The Longitudinal bar tool defines new bars in given insertion points. Set the main properties of the new bar on the tool palette or all properties under Default settings.

 

1585574537495-575.png

Figure: Definition tools and settings of Longitudinal bar

Use one of the following tools to place the new bar in the Cross-section view:

  • Clicking in Cross-section, the new bar will be placed with its center point.

    Align the new bar to a line/edge by select one in Cross-section. Move the mouse to set the bar’s relative position to the selected line/edge: the center point/upper/bottom/left/right surface will be on the line/edge.

    1585574594615-151.png
    Figure: Placement of a bar aligned to an inner edge of a stirrup

    Align the new bar to a corner defined by two lines/edges. The bar will be tangent for the first and then the second given line.

    1585574634232-127.png
    Figure: Placement of a bar aligned to a corner of a stirrup
    1. Define the group of longitudinal bars by set the number of the horizontal (nc), vertical (nr) bar numbers and the distance between the rows (c)

      1585574682296-722.png
      Figure: Placement of bar group
  • The steel bar length can be defined manually by giving the bar’s start and end point in 3D view.

1585574715281-941.png

Figure: Steel bar length definition

1585574735562-803.png

The Stirrup tool defines new stirrups with given shapes. Set the main properties of the new stirrup bars on the tool palette or all properties under Default settings.

1585574751507-414.png

Figure: Definition tools and settings of Stirrup

Choose the contour geometry of the new bar and define the bar’s relative position to the contour with Alignment, which also defines the final stirrup shape with the Cover value in the Cross-section view. In the final step, the distribution of the stirrups based on the Distance value is defined with a start and an end point in the 3D view.

1585574792425-508.png

Figure: Stirrup geometries

1585574806132-660.png

Figure: Placement of stirrups

light.pngThe contour defines the stirrup shape, if the Cover value is set to 0.
1585574885365-773.pngYou can modify the properties (quality, diameter, profile etc.) of previously defined bar/stirrup reinforcement(s) with the Properties tool of Longitudinal bar and Stirrup.
1585574877068-421.png

To exit from Manual design with validating the new and modified reinforcement bars and stirrups, click OK.

1585574893040-889.pngTo exit from Manual design without accepting the defined and modified reinforcement, click Cancel.

Result window tools

In Result window tools one can chose the result type to display (interaction surface of the designed bar, or a summary of utilizations for different design checks) and customize displayed results.

When Result window is activated, Result window tools pops up. It contains options to control the content of Result window.

1585574960130-362.png

Detailed Result

Utilization of RC bars can be displayed in the following cases:

  • After global Auto design, you can display utilization of all concrete bars calculated from the suggested applied reinforcement.
  • When running element-based Auto design, utilization can be displayed by designed elements.
  • After Manual design, element-based Check displays utilization for selected elements.
  • After global Check done for all bar elements having final applied reinforcement.
No.Global Auto designElement-based Auto des.Element-based CheckGlobal Check
11585575005981-456.png  Calculate > Design calculation > Auto design all structural elements1585575049743-145.png  Auto design

1585575051197-655.png  Auto design and/or

1585575059246-927.png  Manual design

1585575052733-563.png  Auto design and/or

1585575060959-401.png  Manual design

21585575031937-940.png  New result>RC bar1585575033517-591.png  New result>RC bar1585575043780-535.png  Check1585575066490-892.png  Apply changes
3  1585575035131-212.png  New result>RC bar1585575009710-257.png  Calculate > Design calculation > Auto design all structural elements
4   1585575036716-815.png  New result>RC bar

Table: Steps of displaying RC bar utilization by different design cases

1585575107870-878.png

Utilization displayed with New result appears for all designed bars. The utilization components for a bar/design group can be displayed with Detailed result.

Detailed result opens a new windows in the current project after selecting a bar/group member, which display:

  • Applied reinforcement
    The figure gives the distribution of the applied reinforcement.
    1585575156969-401.png
    1585575173680-383.png
    1585575182146-966.png
  • Cross-section data
    The figure gives the cross-section datas: height, width, area, moment of inertias.

    1585575222649-783.png
    Figure: Cross-section datas
  • Material properties
    In Materials section, the program shows the material properties of the applied concrete’s and reinforcement, e.g. compression strength (fck), the mean tensile strength (fctm), mean Young modulus (Ecm).
    1585576295877-304.png
    Figure: Material properties
     
  • Calculation formulas
    This contains the EN1992-1-1 formulas for checking RC bar elements, the substitutions in the formulas and the calculation table for each cross section. In the table, the amount of cross-section calculations can be set in the Display options.
    1585576327858-639.png
    Figure: Formulae
  • Detailed calculation tables
    Calculation details and final values are collected in tables sorted by checking types and under utilization graphs by default. Column number depends on the number of calculation sections or the table settings defined with Display options.

    1585576356168-669.png
    Figure: Detailed calculation table
  • Stress-strain graphs
    Different colors display the strain (red) and the concrete stress (cyan) curves grouped by Section utilization (ultimate limit states) and Crack width( serviceability limit states). Also the compressed concrete zones are shown with cyan fills in the calculation sections. The number of displayed sections can be set with Display options.
    1585576382509-523.png
    Figure: Stress-strain graphs by sections
  • Utilization graphs
    Section (Eurocode 2: 6.1), Stirrup (6.2, 6.3), Concrete (6.2, 6.3), Torsional reinforcement (6.3) and Crack width (7.3) utilization graphs together with a Summary graph are displayed with legends by default. Numeric values can be inquired in the calculation sections (Design calculation parameters sets the maximum distance of sections).
    1585576405132-160.png
    Figure: Utilization graph

1585576419524-426.png Tabmenu contains the following tools and settings:

  • Selection of element to display
    You can choose a unique or a design group member from the drop-down lists to display its detailed results mentioned before. Each row displays the ID and the maximum utilization of a member. In case of a design group, “Maximum” means the significant member having the maximum utilization.
    1585576431066-730.png
    Figure: Selection of a unique or a group member
  • Selection of design load
    Depending on RC design was done for load combinations or load groups, a load combination or the maximum or a significant component of load groups can be selected for detailed results. Each row displays the name of the load combination/load group component and its utilization effect. “Maximum” means the significant load combination or component of load groups.
    1585576462921-436.png
    Figure: Selection from design loads
  • 1585576488674-207.png Auto design
    Quick Auto design can be done for the currently displayed unique/group member. Its design parameters can be set/modified in the appearing dialog, and then clicking OK starts RC design that updates all detailed result figures and tables.
  • 1585576562395-771.png Manual design
    Manual design can be launched directly for the currently displayed unique/group member. Returning from reinforcement editing updates all detailed result figures and tables.

  • 1585576602329-437.png Display options
    The content and the appearance of the detailed result can be set with Display options. For tables or stress-strain graphs, you can choose all, maximum and characteristic calculation sections to display.

    1585576584922-303.png
    Figure: Display options of Detailed result

  • 1585576722081-131.png Go to
    Navigate in the RC bar detailed result window by selecting the required design type in the drop-down list. It is useful when you are in zoomed view.

1585576635456-709.png Click Tools > Add view to document to place all figures and tables or specified details only into Documentation.

light.pngExport RC bar reinforcement into *.dwg or *.dxf file format by clicking File/Export to/Export to AutoCAD…

Surface Reinforcement

Surface reinforcement design needs internal forces from Analysis calculations applied for Load combinations or Load-groups and initial reinforcement properties (direction, shape, steel quality, diameter and concrete cover) defined by 1585577052509-329.png  Design calculation parameters.

1585577056793-788.png

Figure: Initial reinforcement settings

warning.pngThe reinforcement shape (Straight/Centric) and the bar directions (x’/y’/r/t) set by Design calculation parameters will be fixed parameters in Auto and Manual design, so only they can be edited/modified only with Design calculation parameters.
warning.pngAlthough all design results can be calculated for all reinforcement types, Auto design does not work for the Centric reinforcement! Only Manual design can be used to define and edit the required centric reinforcement area.

A Plate or Wall can be specified as single layer reinforced by defining “Single layer reinforcement” Calculation parameter for it.

1585577157011-465.png

Figure: Single layer reinforcement definition

In the Calculation parameters dialog the User can define the followings:

  • the quality and diameter of the reinforcement for both directions,
  • the direction of the bottom layer,
  • the distance of the reinforcement from the centreline,
  • the allowed crack width on the bottom and on the top of the structure.

1585577168021-584.png

Figure: Calculation parameters for single layer reinfrocement

light.png

Crack width values that exceed the specified limit are displayed with a different colour. The maximum allowed value of crack width can be set at the Calculation parameters (1585577233282-421.png ). At the Display options (1585577238171-668.png ), the weight, scale and colour of the crack lines can be defined.

1585577247912-522.png

If a shell has “Single layer reinforcement” Calculation parameter, its Design parameter can be modified only if “Single layer reinforcement” option is selected in Auto design/Parameters.

1585577261014-979.png

Figure: Auto design parameters of single layer reinforcement

In case of Manual design, single layer reinforcement can be placed only on „Mid, x’/r” and „Mid, y’/t” layers.

1585577270520-105.png

warning.pngSingle and double layer reinforcements cannot be used in the same Plate or Wall element.

Auto Design

1585577320756-735.png

Global Auto design gives design force and required reinforcement results and suitable applied reinforcement for all concrete surfaces of the current project. Furthermore, Auto design calculates missing reinforcement and crack width based on the determined applied reinforcement.

1585577344168-585.png

Figure: Global Auto design and its result

1585577325289-495.png

Element-based Auto design finds the most suitable top and bottom (or mid) reinforcement for selected concrete plate, wall and shell elements or element groups only according to their internal forces and design parameters. Initial settings of the base net and additional reinforcement by positions (Bottom face/Top face/Mid face) and directions (x’/y’/r/t) can be set with the 1585577376339-640.png  Parameters tool of Auto design.

1585577386626-149.png

1585577394393-369.png

Figure: Design parameters

warning.pngThe minimum concrete cover together with bar directions is derived from Design calculation parameters settings.

To run element-based design for the load combinations or the maximum of load groups, select the required members and/or group with the Auto design command and click 1585577441200-429.png  Design tool. The quick process finds the suitable bar diameter for the additional reinforcement from the defined diameter range, calculates the bars’ utilization and distributes top and bottom reinforcement where required.

1585577459680-161.pngThe placed bars can be displayed by their directions and positions with the navigator icons of the Reinforcement layer tool palette.
1585577463865-302.pngThe generated applied reinforcement is also visible in Manual design, where additional reinforcement can be defined or the current state can be edited.
warning.pngIn case of design groups, the applied reinforcement appears only at the Master group member.

Check the tool palette’s Display table box to have a look at the overall utilization results given for the designed surface elements or design groups.

1585577520739-824.png

Figure: Quick summary of Auto design results

The upper table shows the design efficiency and the maximal utilization of the designed single elements and groups based on the given design parameters. The bottom table displays the utilization details of the surface element or the elements of the group selected in the upper table.

 Meaning
1585577530683-910.pngSuitable reinforcement is available
1585577535599-209.png

Suitable reinforcement is not available

Note: Modify the element thickness, material or RC design parameters.

GroupID of a single element or a group name
Design parametersMain applied design parameters
Total weightTotal weight of applied reinforcement
MaxMax. utilization of a single element or the significant member of a group
MinMax. utilization of the less significant group member
ShellID of a single element or a group member
RBXUtilization of bottom x’/r reinforcement
RBYUtilization of bottom y’/t reinforcement
RTXUtilization of top x’/r reinforcement
RTYUtilization of top y’/t reinforcement
CWBUtilization for crack width on the bottom face
CWTUtilization for crack width on the top face

Table: The meaning of symbols, design parameters and utilization results

Quick redesign can be done inside the Utilization table:

  1. Select a surface element or a design group in the upper table.
  2. Modify the design parameters of the current elements under Parameters.
  3. If the selected surface elements already contain applied reinforcement defined by Manual design or earlier Auto design, you can delete it by activating 1585577595890-695.png  on the Auto design tool palette.
  4. Click Design.

Manual Design

1585577613388-525.png Manual design gives tools to define new (applied) reinforcement in concrete plates, walls and shells, or to modify/redefine the reinforcement generated by Auto design.

1585577623132-868.png

Figure: Manual design tools

light.png

If needed, applied reinforcement defined earlier by Auto design or earlier Manual design can be deleted with Edit > Erase. The geometry of the applied reinforcement regions can be edited with the region-related Edit commands such as Region operations.

1585577688421-252.pngTo define new reinforcement in a surface element, first choose the same reinforcement shape (Straight/Centric) set earlier for the surface element with Design calculation parameters.

1585577712826-355.png Choose the geometry of the new surface reinforcement.

Choose the reinforcement layer with 1585577719300-795.png

1585577761264-778.pngSet the position (Bottom face/Top face/Mid face) of the new surface reinforcement.
1585577765553-184.pngSet the direction (x’/r/y’/t) of the new surface reinforcement.

All parameter of the new reinforcement bars can be set under Default settings or the main parameters on the Manual design tool palette.

According to the geometry place the surface reinforcement with its required points. The new surface reinforcement will be situated parallel with the plane of the host element with the defined concrete cover thickness.

1585577789380-876.png

Figure: Additional reinforcement defined with Manual design

warning.pngIn case of design groups, the applied reinforcement of the group Master is editable only.
light.png

The active layer will automatically follow the result displayed: e.g., when showing stresses ont he top surface of a slab, the top layer of reinforcement will be activated.

1585577862999-764.pngYou can modify the properties (quality, diameter, spacing, cover) of previously defined surface reinforcement(s) with the Properties tool of Manual design.
1585577867468-703.pngRunning global (Calculate > Design calculations > Check) or element-based Check the program gives Applied reinforcement result, so the applied area of surface elements can be displayed with Color palette, Contour lines, Graph or Sections mode.

1585577900777-186.png

Figure: Applied reinforcement area displayed with Graph, Color palette, Contour lines, Sections and Bi-direction mode

Shear capacity

FD calculates RC shells (3D Plate, Wall) shear capacity and their results can be seen from New result / RC Design / Shear capacity. These results can be displayed in Graph, Contour Line, Color palette and Section format.

1585577917181-977.png

No shear regions

This is a specific region which allows to neglect shear in it. When entering RC tab, automatic No shear regions are generated for RC plates,

  • at column intersection points
  • along wall intersection lines
  • at point and line supports.

Width of these regions depends on plate thickness and a factor that can be modified. One can also edit or inactivate these regions, but they cannot be completely deleted. User can also defineNo shear regions manually by launching No shear region command.

1585577926450-338.png

Properties can only be applied for automatically generated No shear regions. Their x factor can be modified and they can be set to Inactive. With Reset option, automatically generated No shear regions can be set to default shape.

1585577933173-132.png

Shell buckling

The buckling problem of the shell is transformed to the buckling of equivalent columns made from the shell, on which the second order resistance and utilization is calculated.

warning.pngOnly RC Plane plates and Plane walls with straight reinforcement and uniform thickness are suitable for shell buckling calculation.

The calculation process is based on so-called buckling regions, which can be defined at RC design/Surface reinforcement/Buckling length.

1585577974695-846.png

Each buckling region on the shell has a corresponding buckling factor (beta) and a direction vector in the plane of the shell. The former will be used to calculate the buckling length of the equivalent column, while the latter one specifies the x’ longitudinal axis of this column. By default, FEM-Design generates one buckling region on each RC wall and plate. Default buckling direction is vertical on walls, and parallel with the local x axis on plates.  Buckling factor is set to 0.0 on all shells in order to let the User decide whether this calculation is needed or not, since it is quite time consuming.

light.pngShells with zero buckling factor will not be considered for shell buckling calculation, but zero utilization is set for them.

The default buckling regions can be modified by adding new regions to the shell. One shell may have more buckling regions with different beta factor and direction vector, but the shell must be completely covered by these regions.

1585578009012-980.png

During the checking process, the program generates equivalent bar(s) from the shell based on its material, thickness and reinforcement. This bar is checked as an RC bar: Its utilization is calculated by determining its second order internal forces and resistance.

The calculation process consists of the following steps:

  1. As other shell design calculations, the shell buckling is also calculated in every node of the shell (only where there is a buckling region with non-zero beta value).
    1585578021942-234.png
  2. An equivalent bar is generated for the examined node as follows. The edges of the shell are intersected by the ray determined by the node and the direction vector of the corresponding buckling region. The two intersection points are taken as the start and the end point of the equivalent bars.
    warning.pngNote that this intersection is always made with the edges of the shell and not with the edges of the buckling region corresponding to the node! If a node is on the border of two or more buckling regions, it is calculated with both different beta values and direction vectors, and the higher utilization will be used.

    1585578078770-899.png
     

  3. The cross section of the equivalent bar is 1 m wide and its height equals to the thickness of the shell. Along the bar, the applied reinforcement of the shell is transformed into the direction of the bar and placed into it.
    1585578130458-333.png
    The checking process is executed section by section along the bar. The distance between these sections is given by Division length of substitute column parameter in Calculation parameter dialog (see the lower figure). Internal forces acting at these sections are calculated by transforming shell internal forces at the section point into the coordinate system of the column. As the buckling direction of shells is perpendicular to its plane, we need the equivalent bar’s normal force and moment vector in the plane of the shell for the calculation.

    1585578173612-713.png
  4. Once the first order internal forces are obtained in every section, the second order internal forces are calculated based on the nominal stiffness or nominal curvature method, according to the configuration settings. The only difference in the checking process of a real bar and this equivalent bar is that now the eccentricity coming from the second order effects are applied only perpendicularly to the plane of the shell. In other words, the out-of-plane normal force has eccentricity only along the z’ axis of the shell. This modification is in harmony with the fact that the buckling direction of the shell is perpendicular to the plane.
    1585578216982-698.png
  5. Finally, based on the second order internal forces, the utilization is calculated for every cross section of the equivalent bar (based on the interaction curve), and the highest section utilization is assigned to the node.

Shell buckling calculations are available for Load combinations, Maximum of load combinations and Maximum of load groups. The utilization results can be displayed in the New result/RC shell/Shell buckling/Utilization

1585578251132-617.png

Some details of the calculation can be obtained by listing RC design/Load combinations/Shell, buckling table. Also, wall buckling utilization appears in the Shell, Utilization list.

1585578261812-195.png

1585578266824-221.png

Every plate and wall has one result, containing the coordinates of the dominant section, the corresponding reinforcement, first and second order internal forces together with the capacity and buckling factor.

Punching Reinforcement

Punching check and design can be done according to Eurocode 2 both in FEM-Design 1585578320296-696.png  Plate and 1585578325188-763.png  3D Structure modules. It is recommended to perform after Surface reinforcement design, because surface reinforcement influences punching calculations.

The punching regions are automatically defined by the program at the plate – coumn intersections and you can define them manually.

  • 1585578366463-730.png Punching design/check can be done at any point where a punching region is exists. Design and check can be done by these punching zones or by their design groups.
warning.pngThe program does not generate punching objects for columns that are connected to more than one slab at the same level.

Initial properties are needed to be set for punching zones. Use 1585578410543-339.png  Calculation parameters to define the followings:

1585578416186-554.png

Figure:Setting β values for punching objects

  • Beta (β)
    According to Eurocode 2, β coefficient is taken into account as the effect of any eccentricity of loading. Its value depends on column position. The program offers default standard values for column positions: for corner (β=1.5), for edge (β=1.4) and inside columns (β=1.15). These standard values have to de added manually by selected punching zones or by their groups. If you neglect β values, choosing Calculate automatically defines them during design/check process and gives accurate results for β coefficients (see Detailed results).
  • Distance of calculated perimeters (d)

    1585578440697-758.png

    This value is used in slightly different ways in checking and design process:
    • Checking:      perimeters to check between u1 and uout(,ef) are generated with d distance from each other.
    • Design:          searching for uout(,ef) perimeter starts from u1 and distance of checked perimeters from the column is increased by the d distance until uout(,ef) is found.
light.pngCalculation parameters are displayed on the model view by the Punching, calculation parameters object layer.

Auto Design

1585578552569-657.png Global Auto design gives utilization results for punching. Auto design applies the initial punching reinforcement settings.

warning.pngPunching design always deletes the existing reinforcement and generates new one.

Defining punching regions

When clicking on the 1585578595849-773.png , the dialog appears:

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Figure: Punching region toolwindow

First the origin of the local system should be specified, which is also the calculation point for punching. The punching force is taken from the finite element corner node closest to the local system’s origin.

light.pngBefore analysis, the user should place a fixed point in Finite element tab, where a punching calculation is planned to be performed, because in this way it will be surely a corner node, leading to higher precision in punching calculation.

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Figure: Punching region example

If you pick a punching force calculation point away from the region the following appears:

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The punching regions can be modified like with Modify region command and Reset back to original shape if the punching region was automatically generated.

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Punching utilization results can be displayed for the entire model with New result > RC punching > Utilization. Maximum utilization in table format can be also shown with Numeric value. Detailed utilization results can be asked by unique or grouped punching zones with 1585578664025-752.png  (see later). Different colors display the adequacy of the checked punching zones.

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Figure: Global Auto design and its result

1585578689231-274.png Element-based Auto design checks the utilizations against punching and finds required reinforcement for selected zones and/or design groups of zones. Initial settings can be set for required reinforcement by bended bar, circularly placed stirrup and open stirrup types with the 1585578702891-400.png  Parameters tool of Auto design.

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Figure: Design parameters by punching reinforcement type

The symbols of the design parameters are stored on the Punching, design parameters object layer.

To run element-based design for the load combinations or the maximum of load groups, select the required zones and/or groups with the Auto design command and click 1585578723384-537.png  Design tool. The quick process runs detailed utilization and finds the suitable bar diameters for the additional reinforcement.

Check the tool palette’s Display table box to have a look at the overall utilization results.

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Figure: Quick summary of Auto design results

light.pngThe ID of design groups can be shown with the Punching, design groups object layer.

The upper table shows the design efficiency and the maximal utilization of the designed punching zones based on the given design parameters. The bottom table displays the utilization details of elements or design members.

 Meaning
1585578773670-419.pngRC column is suitable for punching without or with shear reinforcement
1585578780446-407.png

Suitable shear reinforcement is not available

Note: Modify the slabs’ surface reinforcement or the design parameters.

GroupID of a unique punching zone or design group
Design parametersThe suitable bar diameter and other design parameters as the reinforcement type
Total weight
  • The “-“ symbol displays that no shear reinforcement is applied
  • Total weight of applied punching reinforcement
MaxMax. utilization of a unique zone or the significant zone of a group
MinMax. utilization of the less significant group member
PunchingID of a unique column or a design group member
CCUtilization for concrete compress
CSUtilization for concrete shear
RSUtilization for reinforcement shear

Table: The meaning of symbols, design parameters and utilization results

Quick redesign can be done inside the Utilization table:

  1. Select a punching zone or a design group in the upper table.
  2. Modify the design parameters of the current elements under Parameters.
  3. Click Design.
light.pngDetailed result summarizes the applied formulas by the design modes and display the applied shear reinforcement (if needed) drawing too.

Manual Design

1585578877098-106.png Manual design gives tools to define new (applied) punching reinforcement in concrete plates, or to modify/redefine the reinforcement generated by Auto design.

The rules of new reinforcement definition, if predefined reinforcement already exists from Auto design:

  • new same-type reinforcement will be added to applied reinforcement,
  • new different type reinforcement always overwrites the previously defined one, and
  • new “open stirrup”-type reinforcement always overwrites the previously defined reinforcement even if it was “open stirrup”.
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First choose the type of the new reinforcement. If you would like to modify/refine a previously defined (generated by Auto design or defined by Manual design in an earlier phase) reinforcement, you also need to set the required type from the drop-down list of Manual design. The 1585578970140-217.png  Properties tool of Manual design can be used for modifying actions.

The tools of Manual design depends on the selected reinforcement type.

Bended bar

First set the reinforcement properties under Default settings, and choose the bar direction according to the local system directions of the related column. Then select the punching zone you would like to be reinforced (with totally new or additional reinforcement) and place the new bars.

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Figure: New bended bar

Stirrup, circular

First set the reinforcement properties under Default settings, then select the punching zone you would like to be reinforced, and finally define the circular form with its inner radius.

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Figure: New stirrups in circular shape

Stirrup, open

First set the reinforcement properties under Default settings, then select a geometrical shape (e.g. rectangular, circular, polygonal) for the stirrup position. Select the punching zone you would like to be reinforced, and finally define the shape in the model view.

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Figure: New open stirrups

warning.pngIn case of design groups, the applied reinforcement of the group Master is editable only. Other group members have symbolic reinforcement figure.

Stud rail (general and PSB product)   

First set the reinforcement properties, placement shape under Default settings, then set the number of studs and select punching region to place the studs.

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Figure: New PSB studs

Running global (Calculate > Design calculations > Check) or element-based Check the program gives utilization result for the applied punching reinforcement.

Detailed Result

Utilization of punching reinforcement can be displayed in the following cases:

  • After global Auto design, you can display utilization calculated from the suggested applied reinforcement.
  • When running element-based Auto design, utilization can be displayed by designed elements.
  • After Manual design, element-based Check displays utilization for selected zones.
  • Global Check done for final applied reinforcement.
No.Global Auto designElement-based Auto des.Element-based CheckGlobal Check
11585579122274-794.png  Calculate > Design calculation > Auto design all structural elements1585579198248-281.png  Auto design

1585579132329-870.png  Auto design and/or

1585579157410-183.png  Manual design

1585579134972-965.png  Auto design and/or

1585579160039-804.png  Manual design

2

1585579150594-818.png  New result > RC punching

1585579148186-362.png  New result > RC punching

1585579192786-380.png  Check1585579203541-107.png  Apply changes
3  

1585579145707-274.png  New result > RC punching

1585579125749-481.png  Calculate > Design calculation > Check all structural elements
4   

1585579143805-878.png  New result > RC punching

Table: Steps of displaying punching utilization by different design cases

1585579213113-622.png Utilization displayed with New result appears for all designed punching zones. The utilization components with calculation formulas and the applied reinforcement (if needed) can be displayed with Detailed result.

Detailed result opens a new window in the current project after selecting a unique zone or a member zone of a design group, which display:

  • Design parameters and applied reinforcement
    The figure displays the calculation perimeters, the design parameters and the applied reinforcement calculated by Auto design (if required) or defined in Manual design.

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    Figure: Calculation perimeters, design parameters and applied reinforcement
     
  • Detailed calculation formulas
    Calculation details and final values are collected by checking types: Concrete compression resistance (Eurocode2: Part 1.1: 6.4.3), Shear reinforcement resistance (Part 1.1: 6.4.3) and Concrete shear resistance (Part 1.1: 6.4.3). The proper results are displayed in green, while the red result warnings you to repeat design. The content of the utilization checks depends on Display options. Not relevant checks can also be hidden.

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    Figure: Utilization formulas and tables
  • Summary graph
    Summary graph is displayed with legend by default.
    1585579334463-785.png
    Figure: Utilization summary

1585579349204-697.png  Tabmenu contains the following tools and settings:

  • Selection of zones checked for punching
    You can choose a unique zone or a design group zone member from the drop-down lists to display its detailed results mentioned before. Each row displays the ID and the maximum utilization of a member. In case of a design group, “Maximum” means the significant member having the maximum utilization.
  • Selection of design load
    Depending on punching design was done for load combinations or load groups, a load combination or the maximum or a significant component of load groups can be selected for detailed results. Each row displays the name of the load combination/load group component and its utilization effect. “Maximum” means the significant load combination or component of load groups.

    1585579362430-213.png
    Figure: Selection from checked elements and design loads
  • 1585579395662-213.png Auto design
    Quick Auto design can be done for the currently displayed unique/grouped zone. Its design parameters can be set/modified in the appearing dialog, and then clicking OK starts punching design that updates all detailed result figures and tables.

  • 1585579417694-583.png Display options
    The content and the appearance of the detailed result can be set with Display options.

    1585579439372-176.png

    Figure: Display options of Detailed result

  • 1585579425669-814.png Go to
    Navigate in the Detailed result window by selecting the required design type in the drop-down list. It is useful when you are in zoomed view.

1585579464502-590.png Click Tools > Add view to document to place all figures and tables or specified details only into Documentation.

Concealed bar reinforcement

Concealed bar allows for designing certain parts of a shell as a bar. For example, a wall region over a door opening can be considered as a concealed beam. The internal forces from shell results are converted to bar internal forces and the checking is done on the bar.

To define a concealed bar select the 1585579478922-631.png  option then  Specify concealed bar 1585579483915-763.png , then select the RC slab or wall and specify the diagonal corners of a rectangulare region (or select exsisting rectangular region).

The bar’s local co-ordinate system by default is parallel with the corresponding region’s local system, but there is an option to define skew concealed bar.

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warning.pngThe concealed bar’s reinforcement is not considered in the shell’s applied reinforcement.
Created by Fredrik Lagerström on 2020/03/30 15:09
Copyright 2020 StruSoft AB
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