How can I transition a Plate Mesh from Round to Rectangular?

Transitioning plates from a circular (or elliptical) to a square (or rectangular) shape can be done easily using some of RISA-3D’s automated generation tools. Below is the procedure for transitioning a circle into a square, but it should be clear how this could be accomplished for other similar shapes.

• On the "Home" tab select "Templates" and then select "Circular Arc"
• Modify the properties of the circular arc to match the image below and then click "OK"

The circle of nodes generated by the template should now look like this:

Next generate nodes in a square arrangement at a distance away from the circle equal to the required offset between the two sections.

• Draw four members forming a square around the circle, as shown in the image below:

• With only the beams selected, click on the “Modify” tab and select “Global” from the "Move" section
• Specify an offset distance of 10ft in the Z increment

Next, we can subdivide the members:

• With only the beams selected, click on the “Modify” tab and select “Add Nodes” from the "Members" section
• Select "Uniform" for the "Spacing Type" and choose "5" for the "Number of Segments"
• When the nodes have been added, delete the members

Next, let's add the plates:

• Snap to an ISO view and rotate such that none of the nodes overlap each other visibly and then draw a triangular plate between the top node on the circle and the top middle node of the square as shown below

• Continue drawing triangular plates until you have covered one quadarant (1/4) of the circle. Be careful to draw each plate in the same order (either clockwise or counter-clockwise, stay consistent)

Your model should now look like this:

• Select all of the plates, click on the “Modify” tab and select “Rotate” from the "Copy" section
• Set the Properties of the "Copy Rotate" as shown in the image below:

The plate transition is nearly done. The only remaining task is to submesh it for better results.

• Select all of the plates, click on the "Modify" tab and select "Submesh Plates""
• Select the "Triangular" mesh option from the Properties and click "Apply to Selected"

The completed model should now look like this: