Mechanical APDL Basic Analysis Guide

An equivalent method for applying the coefficient uses the CMSEL,ALLSEL, and SF commands, as
follows:

CMSEL,S,cmp

ALLSEL,BELOW,ALL

SF,ALL,CONV, 10

Applying a Load to an Assembly

Because an assembly is a group of components, the same principle for loading applies to the assembly,
as follows:

SF,assm,CONV,10

In this case, the coefficient is applied to all nodes in each component within the assembly.

2.6. Specifying Load Step Options.

As mentioned earlier,load step options is a collective name for options that control how loads are used
during solution and other options such as output controls, damping specifications, and response
spectrum data. Load step options can vary from load step to load step. There are six categories of load
step options:

• General Options


• Dynamics Options


• Nonlinear Options


• Output Controls


• Biot-Savart Options


• Spectrum Options

2.6.1. Setting General Options.

These include such options as time at the end of a load step in transient and static analyses, number
of substeps or the time step size, stepping or ramping of loads, and reference temperature for thermal
strain calculations. A brief description of each option follows.

2.6.1.1. Solution Controls Dialog Box

If you are performing a static or full transient analysis, you can use the Solution Controls dialog box to
set many of the load step options described on the following pages. Where applicable, the menu path
to the Solution Controls dialog box is included. For details about using the Solution Controls dialog
box, see Solution (p. 111).

2.6.1.2. The Time Option.

The TIME command specifies time at the end of a load step in transient and static analyses. In transient
and other rate-dependent analyses,TIME specifies actual, chronological time, and you are required to
specify a time value. In other, rate-independent analyses, time acts as a tracking parameter. You can
never set time to zero in an analysis. If you issue TIME,0 or TIME,(blank), or if you do not issue the TIME
command at all, the program uses the default time value: 1.0 for the first load step, and 1.0 + previous

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Specifying Load Step Options