Analysis (Concrete Section)

Last modified by Fredrik Lagerström on 2021/08/09 14:20

When the Analysis program mode is active one or several Ultimate- or Serviceability Limit States can be analysed for sections with a defined distribution of reinforcement. A reinforcement distribution calculated in the Design program mode can e.g. be copied to a Serviceability Limit State loadcase to be analysed in the Analysis program mode.


The input data field

The input data field contains a number of tabs in which the example is being defined. Many of these are identical in the Design and Analysis program modes. The field contains initially the tabs Section information and Section/Loadcase.


Section information

Section information is the same as in Design.


Section/Loadcase

Current section forces, limit states and type are stated in the Section/Loadcase dialog box. Calculations for loads in Ultimate- and Serviceability Limit State are being performed in the Analysis program mode. Ordinary Ultimate Limit loadcases as well as accidental loadcases can be defined for the Ultimate Limit State. The types short term and long term can be stated for a Serviceability Limit Loadcase.

A special marking for any defined shear force for loadcases in Serviceability Limit State indicates that these forces are not a part of the calculation.

When the cross-section and load cases have been defined the Material, Reinforcement input and Calculation settings tabs will be added to the input data field.


Material

Material is the same as in Design.


Reinforcement input

With the Reinforcement input option current distribution of reinforcement is stated or copied from another loadcase.

Main reinforcement

The distribution of reinforcement can be stated in a number of different ways or as a combination of these as described below. The best way to use depends on how complicated the reinforcement distribution that are going to be stated is. Coordinates, diameters and quality of reinforcement are shown gradually in the table above, in which also bars can be defined directly.

  • Standard reinforcement
    With the Standard reinforcement button a dialog box appears from which a number of pre-selected reinforcement suggestions can be chosen, maybe as a start for further editing.

    1628259844434-481.png

    Here, current covers of reinforcement can also be defined.
  • Layer of reinforcement
    With the Layer of reinforcement button a dialog box in which the user quickly can state one or several layers of reinforcement in the lower and/layers of reinforcement state one or several the user quickly can dialog box in which With the Layer of reinforcement button a or upper edge will be displayed.

    1628260035375-808.png

    Current covers of reinforcement can be defined here too.
  • Manage Reinforcement
    With the Manage Reinforcement button a dialog box in which the user can state a distribution of reinforcement graphically will be displayed. This is the most advanced way and gives the user a very powerful tool to quickly and simply state even very irregular reinforcement patterns with mixed diameters if wished.

    1628260233895-732.png

    The Show coordinates option is activated as default, which is why the coordinates for the cursor are shown every time it is being moved across the section. If the right mouse button is pressed the Undo Redo, Settings and Guides options as seen below will be available.

    1628260447613-860.png

    With the Undo option copy, insert, move and delete performed according to the instruction below can be undone. These can be restored with the Redo option. This means that every Undo is a step back and Redo is a step forward, e.g. the latest Delete is being restored again. Under Settings the following options are available: Show bar ID which means that the ID-number and diameter of active bars are being shown, Show coordinates which means that the position of the cursor is shown all the time, and Show Guides which means that the created support lines (see below) are being shown or hidden. Under Guides we have the options Set snap distance and Delete every guide. The first option means that the user can change the 10 mm default distance, i.e. the distance within which a moved bar will automatically end up on a support line. The last option means that any earlier defined support lines disappear.

    Guides
    1628261083868-237.png
    These are intended as an aid for swiftly moving a bar or a group of bars to any position. Horizontal support lines are being created by moving the cursor to the gauge in the upper edge of the picture, pressing the left mouse button down and keep it pressed down until the right coordinate position in the vertical direction has been reached. Pointing at it and then pressing down the left mouse button can then move a support line. Vertical support lines are being retrieved in a similar way via the gauge in the left part of the picture. An arbitrary number of support lines can with this be defined as shown below.

    Define reinforcement
    In order to state an arbitrary distribution of reinforcement, at least one bar of each wanted diameter and strength class has to be predefined using one of the other options described in this section. Four bars have been chosen in the above shown picture; two with 20 mm diameter in the bottom corners and two with 16 mm diameter in the top corners. The first step will be to activate one or more bars by pointing at them and press down the left mouse button. It is also possible to activate a group of bars with a square by pressing down the left mouse button and at the same time drag the mouse over the current bars. Activated bars will be marked in red. Double clicking in an arbitrary point of the  section will deactivate all bars. If the right mouse button is pressed when a bar has been activated, the following options will be displayed.

    Copy
    1628261497535-744.png
    A copy of all active bars will be created by clicking on the Copy button. These will be placed near each original bar for a later removal. The copy procedure can be undone as described above.

    Insert
    A new bar is created between two activated bars (or, as an alternative, to the right of or below the current bar if only one bar is active) by clicking on the Insert button. Insert can be made undone as described above.

    Move
    One or more bars can be moved to an optional position by using Move and then grab one of the bars by pressing the left mouse button. If a group of bars are being moved these will keep their reciprocal distance. Move can be made undone as described above.

    Delete
    The currently active bars will disappear by clicking on the Delete button. Delete can be made undone as described above.

    Example:
    We want to define a bar with a 16 mm diameter on the coordinate x = 200 mm, y = 300 mm. Two support lines that intersect in this point should be defined in order to make the placing easier. Then a bar with this diameter will be activated/selected after which Copy is chosen as shown below.

    1628509016568-782.png

    A new bar is created and placed near the original bar. The next step is to choose Move.
    Keeping the left mouse button pressed while moving it to an optional position then moves the bar. The chosen snap distance (see above) affects the placing itself. The higher the value, the earlier the bar will be pulled into the right point. The new bar is now in the right position as shown below.

    1628509264653-270.png

    By using these commands it is easy to create a totally arbitrary reinforcement distribution.
     
  • Copy reinforcement from loadcases
    With the Copy reinforcement from loadcases option a dialog box will be displayed in which distribution of reinforcement can be copied from a loadcase to another.

    Example:
    A section has been calculated for an Ultimate Limit Loadcase in the Design program mode. The user now wants to perform a analysis in Serviceability Limit State for the current distribution of reinforcement. A Serviceability Limit Loadcase is then created in the Analysis program mode after which the distribution of reinforcement is copied from the Ultimate Limit Loadcase with this option.

    1628511544698-319.png

    Four loadcases have been stated in the example. The distribution of reinforcement for loadcase 1 shall be copied to loadcase 3. Loadcase 3 has therefore been activated which is shown in the status bar in the top right of the program window. The current dialog box shows the remaining loadcases where Loadcase 1 is currently active. The distribution of reinforcement for the active loadcase is shown in the dialog box, and Loadcase 3 will get the same reinforcement as Loadcase 1 by clicking on the Copy button.
     
  • Material
    Strength classes for bars in the table are defined for each bar in the Material column. By double clicking on a bar in the Material column the Material dialog is activated and makes it possible to change material. Active bars have a blue number.
     
  • Copy
    The properties of an active bar can be copied with the Copy command so that a new bar with the same position, diameter and strength class will be created in the list.
     
  • Delete
    Currently active bar in the list will disappear with the delete command.
     
  • Stirrup reinforcement
    Stirrups are stated with current spacing, diameter and strength class. Defined main- and stirrup reinforcements are displayed on the continuously updated drawing area.
    The stirrup reinforcement is removed (see section picture) if spacing is defined as zero.

Calculation settings

Calculation settings is the same as in Design.

Loadcase dependent parameters

Loadcase dependent parameters is the same as in Design.