What's new
By:
Advanced search…

Intriguing.....

A

alexfranke

Senior Member


I'm totally confused. :? Are we talking about solids or liquids here? I think I need to go back and re-read this thread...
 
M

MilesH

Alibre Super User


Real-Flow uses "Particle-Modelling" to simulate liquids. AFAIK, you could also use it to simulate Scotts scenario. I could be wrong, though...
 
I

indesign

Alibre Super User


So you are trying to visually represent the partical distribution caused by ..gravity settling, variable flow consistancy, container flow path..etc......whatever.....

Anyhow are you trying to solid model these points as spheres throughout a container? If so will you supply these points in a spreadsheet or do you wish to have an API do this based on user input? Or have I missed what you are asking entirely?
 
swertel

swertel

Alibre Super User


Point is, I don't know how they are going to settle out. I have a general mathematical represenation based on theoretical packing percentages. With that theory, what does it physically look like?

So no, I don't have a spreadsheet with specific data points. Getting those may be helpful, from the CAD model - in my specific case. For my specific case, I would give a program the packing efficiency, the relative size of the particles (or a range of sizes as the case may be) and I'll start out with it being represented as a sphere. I then want the program to pack these particles withing my given volume that I modeled in the CAD package to see how they really look.

Now for a crystalline lattice structure, I should be able to supply the datapoints for one lattice and then "pattern" that lattice to make my entire volume.
 
A

alexfranke

Senior Member


Now, in but a single word, I will bring this thread back full circle (sphere?) to where it started: "Intriguing..." :) The packing algorithm sounds like an intriguing problem. I must admit, though, I know nothing of packing efficiencies, and I've never even attempted to model a sphere (revolve boss, maybe?) I'd be interested in seeing some of the math you used in your spreadsheet.

So how many particles are we talking about here? Tens, hundreds, thousands? Is each one a separate part or are they all packed into the same part? Could this be a set of 3D points who's names indicate their respective sphere's radius? I'm guessing the volume you're filling is not even close to a simple cube, right?

I think I am recovering from my earlier state of utter confusion :wink:
-Alex
 
swertel

swertel

Alibre Super User


We are talking hundreds of particles that are separate parts, but maybe one non-contiguous solid.

Do a google search for "Shaped Charge Design" and you will see the geometry I'm dealing with.

Do a google search for "Sphere Packing" and you'll get the idea of the math involved. I like this one
http://mathworld.wolfram.com/SpherePacking.html


I have a bunch of videos available, but since we use LS-Dyna they happen to have some very good videos on their website.
http://www.ls-dyna.com/
Click on the avi library link and scroll to the bottom for warhead analysis.
 
C

captainCosmic

Member
Let's continue over afternoon tea...

You guys are so funny this has become quite amusing.

Somebody starts a thread based on a guess because of something someone else might have said [or didn't say in this case]...and every post makes the story grow ever more ridiculas.

Sounds like a bunch of old ladies at afternoon tea. :roll:

Designing in Structural Concrete is not about the particles...it's about the reinforcement...how it is oriented in the structure and how it is linked.

The engineers don't even worry about the particles. They only care about Compressive Strength of the mix and that it [the mix] arrives in the box around the steel in a condition to achieve the required CS...because the inspectors only care about the CS [and they test for it from each batch].

But the Steel...that's another issue...it's all the work because it does all the work.

Any idea what next weeks tea topic will be? :eek:

Alex... :shock: don't get tracked off on this one...ask greg directly. I'm sure he put's his pants on one leg at a time just like the rest of us...

Excuse me ladies...
 
A

alexfranke

Senior Member


Great math link -- thanks. I'll take a closer look this weekend.

My version is limited to something like 25 parts, unfortuantely... :cry:

What sounds like an intriguing problem to me is this: Given a total number of particles (spheres), a packing efficiency, a set of radii (each with a number corresponding to the percentage of total particles), and a simple mold form, what might those particles look like when they "settle" into the given form?

In any case, even this sounds a heck of a lot more complicated than dividing splines... =)

Cheers,
-Alex
 
M

MilesH

Alibre Super User


Alex,

I think you should be able to do this within a single Part (or maybe two).

Steve,

Find your own sandpit if you don't like the sand in ours :p
 
A

alexfranke

Senior Member


Hey capt'n, welcome back! How was Tahiti? :wink:

I rather enjoy the meandering conversation, actually. It's fun for me to think about new problems like this and, believe it or not, I'm actually drinking tea! :) I think I'd be shocked if this were actually the application that the first post was so mysterious about!

To be clear, though, (unless I'm totally off track here) this problem sounds quite complicated and I imagine a solution for it would probably have an extremely narrow appeal. I'm already basically working for peanuts, hoping that college fund contributions will grow over time. My wife would probably divorce me if I tried to tell her that an API application for this would make good "business sense" -- I'm not convinced of that at all.

That said, the problem I stated in my previous post does indeed intrigue me, and I'll surely give it some thought -- I love a good puzzle!

Oh -- and next week's tea topic: How many teeth does a snakehead fish have? :?:

Glad to see you back, captainCosmic.

-Alex
 
A

alexfranke

Senior Member


Yes, particle packing seems like it would be great dissertation fodder, too... By "narrow appeal" I mean there probably aren't a lot of Alibre Deisign users who would want to do this sort of thing...

Those snakehead fish are ugly little critters, aren't they? :shock: I even found recipes for these guys in my search for a tooth count (http://www.snakeheads.org). I bet they taste like chicken.

Cheers,
-Alex
 
swertel

swertel

Alibre Super User


I was even reading an Asian blog that stated that Americans have it all wrong about Snakehead fish. They aren't ruthless and visceous preditors. As a matter of fact, they're very tasty (recipes were included). America should be happy that we can have such an ample supply of tasty fish and not have to worry about the delicate balance of our waterways that our current fishes need to survive.
 
I

indesign

Alibre Super User
Re:

swertel said:
I was even reading an Asian blog that stated that Americans have it all wrong about Snakehead fish. They aren't ruthless and visceous preditors. As a matter of fact, they're very tasty (recipes were included). America should be happy that we can have such an ample supply of tasty fish and not have to worry about the delicate balance of our waterways that our current fishes need to survive.
Click to expand...

Does anyone else think it is wierd that there is a blog on this subject?
 
A

alexfranke

Senior Member


...even weirder, I suppose, that there's a thread discussing the matter on a 3D CAD forum... I can't wait for "Alibre Design 3D CAD" to show up next time I Google "Snakehead fish!" :lol:

In any case, I've asked all the pros -- even posted the "how many teeth" question on the Wikipedia article, but nobody seems to know the answer. Lord knows I don't want to have to go looking for one just to find out how many teeth it has! (With my luck it'll find my back side before I find it!)

Swertel's answer is the best so far. Thanks for the diligent research!

Do you think I'd have a shot at winning the design contest if I model a snakehead fish? :roll:

-Alex
 
I

indesign

Alibre Super User


Another great advertising technique!! Post every topic on your forum to get linked by every search known. I am almost interested enough to search on that fish now to. :lol:
 
I

indesign

Alibre Super User


Well I did search for the fish and had no luck at all with the number of teeth. Several references to the nasty rows but no numbers given.
 
You must log in or register to reply here.
Top