Remote Points in ANSYS: What are they and why use them?
- John Parsons
- Nov 9
- 4 min read
Remote Points are the primary technique that ANSYS uses for attaching a node, nodes or a collection of nodes that are scoped by vertices, edges, faces, elements and named selections to a single node called a pilot node. A remote point utilizes a multipoint constraint (MPC) equations for creating the attachment between the selected nodes and the pilot node. In this article we will be primarily focusing on the Rigid and Deformable behavior of the scoped nodes in the FE-model.
Remote Points are used in the creation and attachment of the following:
Point Masses
Joints
Springs
Bearings
Beam Connections
Remote Forces
Moments
Remote Displacements
Therefore the lessons and information deified in this article will also directly carry over to Point Masses, Joints, Springs, Bearings, Beam Connections, Remote Forces, Moments and Remote Displacements.
Let's get started using a simple rectangular steel beam placed in tension. The beam is 10 inches long, 1 inch wide and 0.15 inches thick. The beam has been split into three pieces the first section of the beam is 2.5 inches long, the second section is 5 inches long and the third section is 2.5 inches long. The three sections of the beam are joined together as a single part eliminating the need for contacts or merging nodes. The beam is made from steel with a Modulus of Elasticity of 2.9E7 psi.
Let's mesh the model using our default sizing.
Now that we have this model meshed lets add a remote point that attaches all of the nodes in the center section of the beam to a single pilot node.
For our beam in tension example lets hover over Model in the model tree, right click then hover over insert and select Remote Point. We have now added a undefined remote point to our model.
In order to define this remote point the we must first define the nodes that are connected to the pilot node. ANSYS mechanical gives us the option to select individual nodes, vertices, edges, faces, elements and named selections for the scoping method. Please note ANSYS may give us the option to select vertices, edges, faces, elements and named selections for a scoping method but in the background ANSYS will convert your selection to a collection of nodes.
For this example we will select all of the nodes in the center section of the beam. Simply hide the first and third section of the beam, now using the selection filter select nodes, then simply box select the center section of the beam or right click and choose select all.
Next we need to define the location of the pilot node. ANSYS allows us the ability to select our coordinate system and define the X, Y & Z coordinates of the pilot node relative to our selected coordinate system. Since we selected all of the nodes in the center section of the beam ANSYS has the defined the X, Y and Z coordinates as the center of these nodes and defined the coordinate system as the Global Coordinate System. To make the Remote Point easier to see in this model let's change move the Pilot Node of the Remote Point to 1.0 inch in the Y coordinate. Again this is step is not necessary, but it will more clearly show where the pilot node resides.
Let see what this remote point looks like. Select the Display Tab, then select Remote Point Connections.
Now we are at the heart of this article, the Behavior for this Remote point. For this first run let's set this Behavior to Rigid.
We can now Fix one side of the Beam and add a tensile force of 1000 lbf.
Before we look at these ANSYS results let's predict what we expect to happen. Since we set the remote point to be Rigid, we have mathematical coupled these nodes using MPCs. We have explicitly modeled 10 inch long beam in ANSYS, but 5 inches of that beam is infinitely rigid, there for this 10 inch long beam should be have as a inch long beam.
Now lets look at the results. We have excellent correlation between our hand calculations and this FE-model with a Rigid Point Mass.
Let's get this beam to behave normally. Highlight our Remote Point and change Behavior from Rigid to Deformable. Now lets re-sovle our FE-model.
Please don't peak at those results, let's predict what we expect to happen. Since we set the remote point to be Deformable, the nodes will be free to move independently and expand when this load is applied. We have explicitly modeled 10 inch long beam in ANSYS, there for this 10 inch long beam should behave normally.
Now we ca look at the results. Once again we have excellent correlation between our hand calculations and this FE-model with a Deformable Point Mass.
Let's recap what we have learns Remote Points are extreme versatile and are used in the creation of Point Masses, Joints, Springs, Bearings, Beam Connections, Remote Forces, Moments and Remote Displacements. The behavior of Remote Points can be defined as Rigid or Deformable. When the behavior of a Remote Point is set to Rigid the nodes of the Remote Point are mathematically locked together, basically they are infinitely stiff. When the behavior of a Remote Point is set to deformable Remote Points are flexible and add no stiffness to the system. There are other options for defining the behavior of a Remote point such as Coupled and Beam, we will cover these options in Part 2 of Remote Points.
Thank you for taking the time to read this article and please contact me if you have ideas for future articles.
John Parsons
Analyst
MESim LLC