Creating Smooth Virtual Parts

A Smooth Virtual Part is a rigid body connecting a specified point to specified part geometries, behaving as a mass-less rigid object which will softly transmit actions (masses, restraints and loads) applied at the handle point, without stiffening the deformable body or bodies to which it is attached.

The Smooth Virtual Part does approximately take into account the elastic deformability of the parts to which it is attached.

The program proceeds as follows:

	a node is created in coincidence with the specified handle point.
	all nodes of the specified geometry supports meshes are connected by a kinematical spider element to the handle node.
	a set of mean (constr-n) relations is generated between the handle node degree of freedom and the connected nodes degree of freedom.

The Smooth Virtual Part is built with a Smooth Spider element.

To know more about this element, see Smooth Spider in the Finite Element Reference Guide.

Smooth Virtual Parts can be applied to the following types of Supports:

Mechanical Feature	Geometrical Feature				Analysis Feature
Mechanical Feature	Point or Vertex	Curve or Edge	Surface or Face	Volume or Part	Analysis Feature

This task shows how to create a Smooth Virtual Part between a point and a geometry support.

You can use the sample28.CATAnalysis document from the samples directory for this task: Finite Element Model containing a Static Analysis Case and computed corresponding Static Solution. A Part Design point was created on the associated CATPart document.

Before You Begin:
Go to View -> Render Style -> Customize View and make sure the Shading, Outlines and Materials options are active in the Custom View Modes dialog box.

1. Click the Smooth Virtual Part icon

The Smooth Virtual Part dialog box is displayed.

2. Select an edge or a face of the part as geometry support. In this case, select a face.

3. Position the cursor on the Handler field in the Smooth Virtual Part dialog box and select a point or a vertex as the handler point (the handler point symbol appears as your cursor passes over it). In this case, select a point.

If you do not specifically select a point, the centroid (the point at which the lines meet) will be used as the handler point.

4. Click OK to create the Smooth Virtual Part.

When several virtual parts share a same handler point, only one finite element node is generated.

The symbol appearing at the handler point represents the Smooth Virtual Part.

A Smooth Virtual Part object appears in the specification tree under the active Nodes and Elements objects set.

	You can select several geometry supports.
	The Smooth Virtual Part will connect all supports to the handle point and softly transmit all actions as a rigid body.