PROPERTY INITIAL

A FEMGEN initial condition definition is made up of a initial condition type (e.g. ITEMP), a geometric part to which the initial condition is applied and some real number data to describe the initial condition magnitude and possibly direction.

This initial condition data is extrapolated to the finite element mesh associated with the FEMGEN part in a variety of ways depending upon the initial condition type. For example ITEMP initial conditions are extrapolated to nodes, ISTRESS to element centroids.

It is important to note that a separate item of geometry must be located where the initial condition is to be applied (unless a Load Mask is used) and that the magnitude of all initial conditions is constant over the part (except where a Space Curve is used). The following command illustrates the simplest form of initial condition definition; for more complex initial condition definitions see the advanced loading descriptions in section 2.14.5.1. All advanced loading options except time curves are applicable to initial conditions.

**Figure 2.107:** Example Initial condition
$\begin{figure} \centerline{ \psfig {figure=diagrams/ic1.ps,width=4.0in} }\end{figure}$

FEMGEN includes a number of default initial condition types (listed later in this chapter) in what is referred to as the NEUTRAL Environment. Other initial condition types may be available if an analysis environment has been selected via the PROPERTY FE command. Where an analysis environment has been selected the Interface Program User guide for that analysis package should be consulted for definitions of the initial conditions which appear in the FEMGEN menus.

In the FEMGEN NEUTRAL environment PROPERTY INITIAL has the following sub-commands:

2.14.4.1	PROPERTY INITIAL DEFINE	-	Used for model archiving purposes
			only; do not use.
2.14.4.2	PROPERTY INITIAL IPRESS	-	Define a pressure initial condition.
2.14.4.3	PROPERTY INITIAL ISTRESS	-	Define a stress initial condition.
2.14.4.4	PROPERTY INITIAL ITEMP	-	Define a temperature initial condition.
2.14.4.5	PROPERTY INITIAL IVEL	-	Define a velocity initial condition.