Creating Nodes

FEM Modeling > Create Action (FEM Entities) > Creating Nodes

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Creating Nodes

Create Node Edit

Description

The XYZ method creates nodes from defined cartesian coordinates or at an existing node, vertex or other point location as provided in the Point select menu.

Application Form


Node ID List	Displays the ID of the next node that will be created.
Analysis Coordinate Frame	Specifies local coordinate frame ID for analysis results. The default ID is the active coordinate frame.
Coordinate Frame	Allows definition of nodal location in a local coordinate frame. Any location(s) specified in the Node Location List Select databox (on this form) are defined to be in this Reference Coordinate Frame. The default is the active coordinate frame. The Show Action will optionally report nodal locations in the Reference Coordinate Frame See Show Action.
Associate with Geometry	Indicates whether nodes should be associated with the geometry on which they are created. When the toggle is ON, nodes are associated with the point, curve, surface or solid on which they are created. Normally nodes should be associated, since loads and BCs applied to the geometry are only applicable to nodes and elements associated with that geometry. However, when selected OFF, additional methods of entering nodal location are available.
Node Location List	Specifies node locations by entering coordinates, or by using the select menu. All locations are in the Reference Coordinate Frame.

Create Node ArcCenter

Description

The ArcCenter method creates a node at the center of curvature of the specified curves which have a non-zero center/radius of curvature.

Examples

Note that, to enhance visual clarity, the display size of the points in the examples has been increased with the Display>Geometry command.

1. Node 9 was created at the center point of an arc (Curve 1).

2. Node 4 was created at the curvature center of edge 2 of surface 5 (Surface 5.2).

Application Form


Node ID List	Displays the ID of the next node that will be created.
Analysis Coordinate Frame	Specifies local coordinate frame ID for analysis results. The default ID is the active coordinate frame.
Coordinate Frame	Allows definition of nodal location in a local coordinate frame. Any location(s) specified in the Node Location List Select databox (on this form) are defined to be in this Reference Coordinate Frame. The default is the active coordinate frame. The Show Action will optionally report nodal locations in the Reference Coordinate Frame.
Curve List	Specify the existing curves or edges either by cursor selecting them or by entering the IDs from the keyboard. Example: Curve 1 Surface 5.1 Solid 5.1.1. The Curve Select menu that appears can be used to define how you want to cursor select the appropriate curves or edges.

Extracting Nodes

Description

With this command you can extract and display a node at any point of a curve or edge, and one or more nodes at any point of a face, at specified parametric distances from the parametric origin.

Examples

1. Node 6 of Curve 1 was extracted at a parametric distance of u=0.67.

2. Node 5 of Surface 2 was extracted at the center of the surface (u = v = 0.5).

3. Several nodes of Surface 20 were extracted within specified parametric boundaries.

Application Form

1. Extract a node from a curve or edge


Curve Symbol	Indicates that the geometry from which a node will be extracted is a curve.
Node ID List	Displays the ID of the next node that will be created.
Analysis Coordinate Frame	Specifies local coordinate frame ID for analysis results. The default ID is the active coordinate frame.
Coordinate Frame	Allows definition of nodal location in a local coordinate frame. Any location(s) specified in the Node Location List Select databox (on this form) are defined to be in this Reference Coordinate Frame. The default is the active coordinate frame. The Show Action will optionally report nodal locations in the Reference Coordinate Frame.
Parameterization Method
• Equal Arc Length	The parametric distance value specified for u is calculated in terms of equal-length arc segments along the curve.
• Equal Parametric Values	The parametric distance value specified for u is calculated in terms of equal parametric values.
Parametric Position	Specify the curve’s or edge’s coordinate value, where has a range of , either by using the slide bar or by entering the value in the databox. The direction of is defined by the connectivity of the curve or edge. You can plot the direction by choosing the Parametric Direction toggle on the Geometric Properties form under the menus Display/Display Properties/Geometric.
• Slide Bar	Move the slider to a desired parameter value (). The databox will show numerically the position of the slider along the parametric length.
• Counter (databox)	If greater accuracy is desired, type a specific value into the databox. In turn, the position of the slider will change to reflect the numerical value in the counter.
Curve List	Specify the existing curves or edges either by cursor selecting them or by entering the IDs from the keyboard. Example: Curve 1 Surface 5.1 Solid 5.1.1. The Curve Select menu that appears can be used to define how you want to cursor select the appropriate curves or edges.

2. Extract a node from a surface or face


Surface Symbol (One point)	Indicates that: a.) the geometry from which to extract is a surface, and b.) only one node is being extracted.
Node ID List	Displays the ID of the next node that will be created.
Node Coordinate Frame	Select the Analysis Coordinate Frame and the Reference Coordinate Frame.
Parametric Position
• u Parametric Value	Move the slider or enter a value in the databox to specify the parametric distance from the parametric origin of the point in the u direction.
• v Parametric Value	Move the slider or enter a value in the databox to specify the parametric distance from the parametric origin of the point in the v direction.
Surface List	Specify the existing surfaces or faces to create nodes on, either by cursor selecting the surfaces or faces or by entering the IDs from the keyboard. Example: Surface 1 or Solid 5.1 The Surface Select menu that appears can be used to define how you want to cursor select the appropriate surfaces or faces.

3. Extract multiple nodes from surfaces or faces


Surface Symbol (More than one point)	Indicates that: a.) the geometry from which to extract is a surface, or face and b.) several nodes are being extracted.
Node ID List	Displays the ID of the next node that will be created.
Node Coordinate Frame	Select the Analysis Coordinate Frame and the Reference Coordinate Frame.
Number of Nodes
• u direction	Designates the number of nodes extracted in the u parametric direction.
• v direction	Designates the number of nodes extracted in the v parametric direction.
Bounds	Specify the Bounds as Diagonal Points when two point locations are to be used to define the boundary for the nodes to be extracted from the surface.
Parametric Bounds...	Brings up a secondary form in which you can define the upper and lower u and v limits of the area boundaries.
u-Min/u-Max	Displays the u-directional parameter values that define where the delimited area of the surface begins and ends.
v-Min/v-Max	Displays the v-directional parameter values that define where the delimited area of the surface begins and ends.
Point List 1 Point List 2	Specify the two points to define the diagonal for the points, either by cursor selecting the points or by entering the IDs from the keyboard. Example: Point 1 or Curve 1.1, Surface 1.1.1. The Point Select menu that appears can be used to define how you want to cursor select the appropriate points.
Surface List	Specify the existing surface or face to create nodes on, either by cursor selecting the surface or face by entering the IDs from the keyboard. Example: Surface 1 or Solid 5.1 The Surface Select menu that appears can be used to define how you want to cursor select the appropriate surface or face.

Interpolating Nodes

Description

This command enables you to interpolate any number of nodes between two existing points, vertices, or nodes, or two arbitrary locations cursor-selected on the screen. The interpolation between two vertices of a curve or edge may be specified either along the actual distance between the two vertices or along the curve or edge itself. Points may be either uniformly or non-uniformly distributed.

Examples

1. Interpolate eight nodes over the distance between vertices 1 and 2 of Curve 1.
Points are to be equidistant.

2. Interpolate eight nodes along the curve between vertices 1 and 2 of Curve 1. Points are not uniformly spaced; the ratio of the longest to the shortest distance between two points is 3.

Application Form

1. Interpolate along the distance between two points


Node ID List	Displays the ID of the next node that will be created.
Node Coordinate Frame	Select the Analysis Coordinate Frame and the Reference Coordinate Frame.
Option	Choose Point or Curve
Number of Interior Nodes	Enter the number of interior nodes you want to create between the specified point locations in the Point 1 and Point 2 Coordinates List.
Point Spacing Method	Select either button for Uniform or Nonuniform nodes spacing for the new interior points. If Nonuniform is ON, then enter the value for L2/L1, where L2/L1 is 0 ≤ L2/L1 ≤ 1.0 or L2/L1 ≤ 1.0.
• Uniform	Interpolated nodes will be equidistant from the original nodes and from each other.
• Nonuniform	Interpolated nodes will not be spaced uniformly. The Application Form will include additional items: Where: L1 = shortest distance L2 = longest distance between two nodes When using the Curve option, L1 will be the distance between the first selected node and the first interpolated node.
Manifold to Surface	If this toggle is ON, the interpolated nodes will be projected onto a selected surface.
Point 1 List Point 2 List	Specify in the Point 1 Coordinates listbox, the starting point location to begin the interpolation. Specify in the Point 2 Coordinates listbox, the ending point location to end the interpolation. You can express the point location either by entering the location’s cartesian coordinates from the keyboard, or by using the Point Select menu to cursor select the appropriate points, vertices, nodes or other point locations. Examples: [ 10 0 0], Surface 10.1.1, Node 20, Solid 10.4.3.1.

2. Interpolate Between Two Vertices Along a Curve or Edge


Node ID List	Displays the ID of the next node that will be created.
Node Coordinate Frame	Select the Analysis Coordinate Frame and the Reference Coordinate Frame.
Option	Choose Point or Curve
Number of Interior Nodes	Enter the number of interior nodes you want to create between the specified point locations in the Point 1 and Point 2 Coordinates List.
Parameterization Method	If Equal Arc Length is ON, Patran will create the node(s) based on the arc length parameterization of the curve. If Equal Parametric Values is ON, Patran will create the point(s) based on the equal parametric values of the curve.
• Equal Arc Length	Parametric dimensions are calculated in terms of the length of equal arc segments along the curve. This method is especially useful when a number of nodes are interpolated and uniform spacing is required, because it ensures that nodes will be placed at equal arc lengths.
• Equal Parametric Values	Parametric dimensions are calculated in terms of equal parametric values.
Point Spacing Method	Choose either button for Uniform or Nonuniform point spacing for the new interior point
• Uniform
• Nonuniform	Interpolated nodes will not be spaced uniformly. The Application Form will include additional items: Where: L1 = shortest distance L2 = longest distance between two nodes When using the Curve option, L1 measures the distance between the parametric origin and the first interpolated node. For determining where the parametric origin is, turn on the parametric axis (Display>Geometry>Show Parametric Direction).
Curve List	Specify the existing curves or edges to create nodes on, either by cursor selecting the curves or edges or by entering the IDs from the keyboard. Example: Curve 1 Surface 5.1 Solid 5.1.1. The Curve Select menu that appears can be used to define how you want to cursor select the appropriate curves or edges.

Intersecting Two Entities to Create Nodes

Description

With this command you can create nodes at the intersections of various entity pairs and at the intersection of three planes. One intersection node will be created at each location where a point of one entity is within the global model tolerance of a point of the other.

Intersecting Entities

The following diagrams show the possible entity pairs for which intersection nodes can be created:

With the exception of the curve/surface combination, “intersection” nodes may be generated even if two entities do not actually intersect. Patran will calculate the shortest distance between non-intersecting entities and place a node on each entity at the location where the shortest distance occurs.

Examples

1. Nodes 5 and 6 were created at the intersections of Curve 1 and Curve 2.

2. Nodes 3 and 4 were created at the intersections of Curve 8 and Surface 1.

3. Nodes 6 and 7 were created where vector 1 would intersect Surface 5 if it were extended.

4. Nodes 8 and 9 were created at the points where the distance between Curve 3 and Curve 4 is the shortest.

Application Form


Node ID List	Displays the ID of the next node that will be created.
Analysis Coordinate Frame	Specifies local coordinate frame ID for analysis results. The default ID is the active coordinate frame.
Coordinate Frame	Allows definition of nodal location in a local coordinate frame. Any location(s) specified in the Node Location List Select databox (on this form) are defined to be in this Reference Coordinate Frame. The default is the active coordinate frame. The Show Action will optionally report nodal locations in the Reference Coordinate Frame See Show Action.
Option (1)	Specifies a curve or vector as the first intersecting entity.
	Also provides the 3 Plane option that will create a node at the intersection of three existing plane entities.
Option (2)	Specifies a curve (edge), surface (face), plane, or vector, that is intersected by the first entity.
Listboxes	The title and contents of the listboxes will depend on what you selected for the two above options; e.g., Curve List (pick a curve or edge), Vector List (pick a vector) and others.

Creating Nodes by Offsetting a Specified Distance

Description

The offset method creates new nodes by offsetting existing points by a given distance along a curve or an edge.Offset distance is specified in model dimensions (not parametric!).

Example

Points 7 through 11 were offset by a distance of 8 units along Curve 1 to create nodes 12 through 14 (notice that point order is maintained).

Application Form


Node ID List	Displays the ID of the next node that will be created.
Analysis Coordinate Frame	Specifies local coordinate frame ID for analysis results. The default ID is the active coordinate frame.
Coordinate Frame	Allows definition of nodal location in a local coordinate frame. Any location(s) specified in the Node Location List Select databox (on this form) are defined to be in this Reference Coordinate Frame. The default is the active coordinate frame. The Show Action will optionally report nodal locations in the Reference Coordinate Frame See Show Action.
Offset Distance	Defines the distance between an offset point and its reference point.
Reference Point List	Shows the IDs of the points selected for offset. You can enter point IDs individually or in a series, or pick points on the screen. Use the Select Menu icons to “filter” your selection, e.g., for picking a vertex or intersection point.
Curve/Point List	Curve: Identifies the curve on which the points are offset. Point: Selects a point that sets the direction of the offset. Pick the curve, then use the Select Menu icons to focus on a particular point type. Alternately, you can double click the curve on the side to which you want to offset the point(s). The first click identifies the curve and, because the Select Menu defaults to “Any point”, with the second click you pick any point as long as it determines the correct offset direction.

Piercing Curves Through Surfaces to Create Nodes

Description

With this command you can create one or more nodes at locations where a curve or edge pierces (intersects) a surface or a face. The pierce point will be created only if there is actual intersection between the curve and the surface (no projected points).

Example

Created Nodes 1, 2, 3 where Curve 1 pierces Surfaces 4.

Application Form


Node ID List	Displays the ID of the next node that will be created.
Analysis Coordinate Frame	Specifies local coordinate frame ID for analysis results. The default ID is the active coordinate frame.
Coordinate Frame	Allows definition of nodal location in a local coordinate frame. Any location(s) specified in the Node Location List Select databox (on this form) are defined to be in this Reference Coordinate Frame. The default is the active coordinate frame. The Show Action will optionally report nodal locations in the Reference Coordinate Frame.
Offset Distance	Input the Model Space offset distance from an existing point on a curve (curve to be input).
Curve List	Displays the ID of the curve (or edge) that pierces the surface.
Surface List	Displays the ID of the surface that is pierced.

Projecting Nodes Onto Surfaces or Faces

Description

Using this command you can project one or more point locations onto a curve, edge, surface, or face. The reference location that is projected may be a point entity, a specific location on other entities e.g., vertex or intersection point, a node, or a location on the screen defined by explicit coordinates or picked with the cursor. The direction of projection may be along the normal of the selected curve or surface, along any defined vector, or along the direction of the view angle of the active viewport. The original reference points may be retained or, optionally, deleted.

Examples

1. Nodes 1-8 are in the global XY plane. Surface 1, parallel to the XY plane, is located at Z= -3. Points 9-16 were obtained by projecting the original reference points to Surface 1 along the surface normal.

2. Nodes 17-24 are the projections of Points 1-8 along a vector V=<0.25 0.75 -3>.

Application Form


Node ID List	Displays the ID of the next node that will be created.
Analysis Coordinate Frame	Specifies local coordinate frame ID for analysis results. The default ID is the active coordinate frame.
Coordinate Frame	Allows definition of nodal location in a local coordinate frame. Any location(s) specified in the Node Location List Select databox (on this form) are defined to be in this Reference Coordinate Frame. The default is the active coordinate frame. The Show Action will optionally report nodal locations in the Reference Coordinate Frame See Show Action.
Project onto	The target where projected nodes will be placed. Your options are: • Curve • Surface • Plane
Direction
• Normal	The nodes are projected along the normal of the curve (edge) or the surface (face).
• Define Vector	The nodes are projected along an arbitrary projection vector that you define.
	The following portion of the form will become selectable:. Here you specify the projection vector and name the reference coordinate frame in which the vector is defined.
• View Vector	The nodes are projected along a vector whose direction is determined by the viewing angle of the current active viewport.
Reference Coordinate Frame	Projection Vector and Refer. Coordinate Frame is used if the Define Vector option is chosen.
Curve List/ Surface List Plane List	Depending on what you selected as the “Project onto” entity, the listbox will display the ID of the curve, surface, or plane you select for receiving the projected points.