Maintain part volume

[Milkman]

I am trying to find a way lock/maintain the volume of a part while allowing one dimension to float so I can make variations to the part without

changing it's mass. Example: I'd like to be able to change the diameter of a cup shaped part while using the same amount of material, so the

height of the cup would vary based on the change in diameter.

Does anyone know of a way to accomplish this?

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[dgschaefer]

I don't have a lot of experience with it, but this sounds like exactly the sort of problem the Behavior Modeling Extension was made for.

[JamesBurcham]

You could do it using relations. Make the variable radius or radii a parameter that is entered by the designer.

Example. If your shape is a cylinder

RADIUS = X (parameter entered by designer)

HEIGHT = PI * RADIUS ^2

DX = HEIGHT

If its not a true cylinder and more of a cup shape with a different radius top and bottom the concept is the same but the equations is more difficult.

TOP_RADIUS = X (parameter entered by designer)

BTM_RADIUS = X (parameter entered by designer)

HEIGHT = 1/3 * PI * (TOP_RADIUS^2 + BTM_RADIUS^2 + TOP_RADIUS * BTM_RADIUS)

DX = HEIGHT

In both example DX represents the dimension defining the height of the object.

This is how I would accomplish this. There are other ways.

The equations necessary to do this will be dependent on your shape and how to calculate its volume. These are just examples of cup volumes.

[Milkman]

Thanks James, but I was afraid the answer was going to involve formulas. Most of the parts I'd like to do this with are much more complex than my example of a cup. Many times, the floating dimension is the length of an angled flange and the formula method would be way more work than it is worth to me. I was hoping since the software can calculate the volume that it could also allow you to set the volume as static allowing me to create my part leaving out one of the defining dimensions.

[ptc-5008082]

If it is just the one dimension that you want to 'leave out' when designing then you will be able to run an optimisation study to aim for a specific volume by varying that one dimension until you get the volume you were after.

You may need to -design a bit - run a study to make sure you're not miles away then -design a bit - run a study etc. The study shouldn't take too long, the only proviso is that you will need Behavioural Modeller Extension to do it.

[TomD.inPDX]

I wanted to do this for a liquid filled gauge. The shape of the liquid constantly changes but I wanted the volume to remain the same. I couldn't get around writing the volume formula in relations to generate the geometry.

[ptc-5008082]

There are always many ways to skin a Pro/E cat (so to speak) but I agree with Doug, sounds like a case for BMX, can you be a little more specific on the design and how flexible you want the variable dimension to be (i.e. infinitly variable or within a likely range etc.) and whether there are other design constraints that might influence the solution?