Table 9.2: Select Commands shows a summary of commands available to select subsets of entities. Notice the "crossover" commands: commands that allow you to select one entity based on another entity. For example, you can select all keypoints attached to the current subset of lines. Here is a typical sequence of select commands:

LSEL,S,LOC,Y,2,6   ! Select lines that have center locations between Y=2 and Y=6
LSEL,A,LOC,Y,9,10  ! Add lines with center locations between Y=9 and Y=10
NSLL,S,1           ! Select all nodes on the selected lines
ESLN               ! Select all elements attached to selected nodes

See the LSEL, NSLL, and ESLN command descriptions in the Command Reference for further information.

The GUI path equivalent to issuing most of the commands listed in Table 9.2: Select Commands is Utility Menu> Select> Entities.

The GUI option displays the Select Entities dialog box, from which you can choose the type of entities you want to select and the criteria by which you will select them. For example, you can choose Elements and By Num/Pick to select elements by number or by picking.

Plotting One Entity Type and Selecting Another

It is sometimes useful to plot one entity type and select another. For example, in a model with hidden faces, you may want to obtain a wire-frame view. You can do so by plotting the lines via Utility Menu> Plot> Lines (LPLOT), and then selecting areas using graphical picking via Utility Menu> Select> Entities> Areas> By Num/Pick (ASEL,S,PICK). This method is available by default.

Combining Entities Into Components or Assemblies

You will likely want to combine entities into components or assemblies wherever possible for clarity or ease of reference. The following GUI paths provide selection options for defined components or assemblies:

When CAD geometry is imported into Mechanical APDL, the transfer may define the display of short line elements, which are difficult to identify on screen.

By choosing the line selection option, you can find and display these short lines:

Enter the minimum and maximum length or radius in the VMIN and VMAX fields. These fields, as they are used in this option, represent the range of values which corresponds to the length or radius of the short line elements. You should enter reasonable values in VMIN and VMAX to assure that the selected set only includes those short lines that you want to display. When the selected set appears on screen, you can pick individual lines within the set and repair the geometry as necessary.

To restore all entities to their full sets, use one of the following:

This one command has the same effect as issuing a series of NSEL,ALL; ESEL,ALL; KSEL,ALL; etc. commands.

You also can use ALLSEL or its GUI equivalents to select a set of related entities in a hierarchical fashion. For example, given a subset of areas, you can select all lines defining those areas, all keypoints defining those lines, all elements belonging to these areas, lines, and keypoints, and all nodes belonging to these elements, by simply issuing one command: ALLSEL,BELOW,AREA

To select a subset of degree of freedom and force labels, use one of the following:

By selecting a subset of these labels, you can simply use ALL in the Label field of some commands to refer to the entire subset. For instance, the command DOFSEL,S,UX,UZ followed by the command D,ALL,ALL would put UX and UZ constraints on all selected nodes. DOFSEL does not affect the solution degrees of freedom.