Add Columns

The Add Columns drop menu provides a number of tools to allow vertical columns to be added to a model quickly and easily. The Add Columns pane includes options to select the column material, section and rotation, set column attributes, automatically assign the columns to member viewing and/or design groups and to input either a single column (one at a time mode) or to add multiple columns at once. Using the Add Columns menu, it is possible to add columns at defined level or by specify a column height and adding the column above or below a specific point which can be selected graphically. The Add Column menu also allows for the base support to be set automatically.

The Add Column window can be selected by going to Create>Add Columns. Alternatively, the short cut key combination Ctrl+Shift+C can be used. This opens the Add Column pane at the right hand side of the screen. The Add Column pane is shown below.

Column Section

The column section to be added can be controlled by the column section tools. The section material can be and cross section type is controlled by a combination of the icons and drop downs at the top of the Add Column window. The icons give the following options:

Add a Steel Section:-

To add a steel section, select the  icon. Once clicked, the drop downs below the icons allow the selection of the steel section type, steel grade, steel section and the input of the column beta angle rotation to be input by typing the relevant angle. The drop down options are as shown below.

The column beta angle can also be controlled using the Column Beta Angle options.

Add a Concrete Section:-

To add a rectangular, square, round, L or Tee section, select the concrete icon.

Then click on the ‘Edit Concrete Section’ icon to open the area where the shape and size of the section can be defined. Save the section before positioning it in the frame.

The section size can be later amended using the Properties > Member Section Materials menu option.

Add a Timber Section:-

To add a rectangular, square or round section, select the timber icon.

Then click on the ‘Edit Timber Section’ icon to open the are where the shape and size of the section can be defined. The moduli, strength and service classes, etc can also be selected. Save the section before positioning it in the frame.

The section size, etc can be later amended using the Properties > Member Section Materials menu option.

In-Use:-

The In-Use option allows for the quick selection of a column section already in use in the model. Selecting the  icon, the drop down options now allow for the selection of any previously input column section.

Attributes

The attributes of the input column section can be controlled through the Attributes section of the Add Column menu. The available options are as shown below.

Note: The Stiff Deck option applies the old style rigid member style stiff deck. This is based on modifying the member minor axis properties to make the member rigid laterally. This approach is less accurate than the semi-rigid style stiff deck method and is not compatible with the Finite Element module.

Member Group Options

The member viewing a design group options allow a column to be created and automatically added to a viewing group, a design group or to both. The relevant group can be selected form the drop down, if any viewing or design groups have already been created. Additional groups can be added by clicking on the  icon and inputting a group name or title in the text input box.

Selection Mode

The Selection mode controls the creation mode and allows single columns or groups of column to be created by varying the input mode.

Single (snap point):- individual columns are added by selecting the input position graphically on in the graphical screen. This mode interacts with the model and grid lines using the snap grid tools.

Multiple (windowed):- the multiple column inputs allows an area to be selected by creating a window around the area in the graphics window. A wind ow is created by placing the mouse pointer at one corner of the desired area, clicking and holding the left mouse button and moving the mouse pointer to the opposite corner of the desired area. To assist in creating a widow around a desired area, the viewing tools can be used to select the required area and view need. The Multiple option interacts with structure or grid lines, to control where columns are created. The Grid Line intersections option interacts with the grid lines to create a column at the intersection of the grid lines which lie within the windowed area. The Beam ends option identifies the ends of physical members to add columns only at the node points at the end of a member - this option prevents columns being added at intermediate nodes.

In both options, the column material, section, beta angle, insertion level, base support conditions and groups are controlled through the options in the Add Column pane.

Where columns have been added, re-selecting them will remove the columns. Thus it is possible to remove a column in the Add Column mode without have to go to Modify Geometry> Delete Members option.

Column Beta Angle

The Column Beta Angle options controls the rotation of the column about its vertical axis. While the Beta Angle input allows a user defined value to be input, the Column Beta Angle options allow for quick alignment of the column major or minor axes with either grid lines or the nearest beam. The available options are dependant on the selection mode activated. The Column Beta Angle options are shown below.

Fig. 4 Column Beta Angle options

Align to nearest beam or grid (single select):-   This option will automatically align the column major axis to the nearest beam or grid line. The nearest beam or grid line is controlled by the proximity to the mouse pointer; the orientation of the column can be controlled by using the snaps to select the insertion point and then moving the mouse pointer to the beam or grid line that the column major axis is to be aligned with, The mouse pointer will indicated the column orientation. Selecting the Minor Axis checkbox means that the mouse inputs control the orientation of the minor axis rather than the major axis, though the input method remains the same. This option is only available in the single selection mode.

Auto align with grid lines (single or multiple select):-   This option automatically aligns the column with the selected grid lines set. The grid lines to be aligned with is controlled by the Set 1 or Set 2 radio buttons. The default input mode is to align the column major axis - the minor axis can be used by selecting the Minor Axis checkbox.

Flip Beta Angle 180º:-   This option reverses the column orientation. This can be useful on elevations and for portal frames where the loading is to be applied to the "outside" face of the column.

Column Y Values

The Column Y values area controls the column length and whether or not the column is added above or below a point when selected graphically. A column can also be added between user specified levels which then controls the start and finish level of the column. The levels defined in the Create>Add Levels input can also be used to control the input levels for columns.

Base Support

The base support options allow for the control of the nodal support at the base of any added columns. These options allow for the automatic creation of a support condition at the lower end of the column. The options are:

Pinned:-  creates a pinned nodal support at the base of the inserted column.

Fixed:-    creates a fixed nodal support at the base of the inserted column.

None:-    no nodal support is added at the base of the inserted column length.

In the case of the Pinned and Fixed Base, each input column section will have the selected support condition applied at the lower end of the column, even if the column is being added above another column length. To prevent this option, the Support at Free End Only tool can be selected; using this, the column base will only have a support where the end is free i.e. there are no other members framing into that end of the column.