Parametric Analysis Features?

[mloew]

Hello all,

I using a Pro/E parametric model representing the mass centers of the sub systems of a vehicle to determine the loads on the axles. I am using analysis features to drive the size of a cube protrusion to a certain mass as a relation. The mass of each solid feature is therefore hard-coded. The code of the analysis feature looks like this:

mass=(some real number)
length=(mass)^(1/3)

There is a relation for each protrusion feature that sets the depth equal to the length, so I end up with a cube sized to produce the mass I indicate. The density of the part is set to unity, BTW. Is there a way that the mass can be used as a parameter suitable for modifying in an optimization study? I can break the groups, suppress the analysis feature and drive one of the dimensions of the protrusion, but I was looking for something a bit more elegant. I can see using part parameters to do the job, but I would like to avoid them due to the number of parameters already present at the part level.


I would appreciate any comments. Thank you.
Best regards,

Matthew Ian Loew

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Hora]

Hi Matthew,

If you have the "Behavioral_Modeler" licence you can make an optimisaton of your model by seting the goal of your part/assembly to be the mass you desire.

-Hora

 

[mloew]

Hora,

Thanks for the reply. That is exactly what I am trying to do with BMX. My problem is that I can use BMX to change one of the dimensions that controls where the "cube" mass is, but not the mass itself. I think this is because I have it coded in the relation of the analysis feature. If I make the individual masses parameters of the part, BMX will allow me to control that as an optimization variable. I am resistant to do this as the standard set-up of the part files have a lot of part parameters already so modifying them as parameters is cumbersome. I tried feature parameters as well; BMX did not seem to be able to modify them. Any tricks around this? Best regards,

Matthew Ian Loew

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Hora]

Matthew,

Replace the relation:

mass=(some real number)

with this one:

mass = mp_mass("&quot

and then add mass parameter as a goal in your analysis.

-Hora

 

[mloew]

Hora,

Thank you again for your reply. The relations that I have are for each individual feature representing a major sub-system on a vehicle. So the mass that I have in the analysis feature relation is for one individual feature. I have a coordinate system, a protrusion, and an analysis feature (in groups) for each sub-system. What I would like to do is do individual studies that allows the mass center and/or sub-system (feature) to change WRT holding other parameters constant and using certain constraints (other analysis features, perhaps the overall mass). Again, if I make the individual sub-system masses represented in a part parameter, I can do what I want; it is just not working if the sub-system mass is represented as a relation in the analysis feature.

I hope this explains my situation a little more clearly. Best regards,

Matthew Ian Loew

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.