Edit Solver Differential Equations
These equations can be used to add additional states to the mechanical system being modeled.

If the Solver Differential Equations panel is not currently displayed, select
the desired solver diff by clicking on it in the Project Browser or in the modeling window.
The Solver Differential Equations panel is automatically displayed.
 Select Static Hold if the state of the solver differential equation is not permitted to change during static or quasistatic analysis of the solver. Otherwise, deselect the option.
 Select Implicit if the differential equation is of type implicit. If the equation is explicit, leave the option unselected.
 Enter a value for the initial condition of the differential equation in the IC text box.

Enter a value for the initial condition for the first
derivative of the user defined variable in the IC dot text box.
This option is usually used in conjunction with an implicit variable.
 Select an option from the dropdown menu at the bottom of the panel.

Define the properties associated with your choice.
If Linear is chosen, enter a value in the text box.If Curve is chosen:
 Select AKIMA, CUBIC, LINEAR, or QUINTIC as the interpolation method.

Enter a value under Independent variable.
The independent variable should be specified in Templex syntax.

Resolve the curve by doubleclicking the Curve
collector and selecting a curve from the Select a
Curve dialog.
Note: To use a curve, you first need to define a curve (using the Curves panel) which represents the behavior of the solver differential equation.
If Spline3D is chosen: Select AKIMA, CUBIC, LINEAR , or QUINTIC under as the method of interpolation.
 Specify an expression for Independent variable X and Independent variable Z.

Resolve the 3D spline by doubleclicking on the
Spline3D collector and selecting a Spline3D
entity from the Select a Spline3D dialog.
Note: To use a Spline3D entity, you first need to define a spline using the Spline3D panel.
If Expression is chosen, enter an expression.