Calculating deflection on complex geometries

[Ed from NY]

Hi,

I was wondering if there are any shareware/freeware/demo programs that would allow us to import a 3d part, define the material, add forces and calculate deflections.

Actually just calculating some sort of the new elasticity modulus would be great as I just want to compare designs and materials.

For example if I make the design on top out of Aluminum-7075-T7351 we have a 50% reduction in weight when compared with the design at the bottom made out of steel 1018. Besides the addition of webbing there are changes in thickness, etc.

However, the purpose of the plate is to keep motor, spindle and sheaves true. So I wanted to get an idea of what I'm giving up in rigidity because the modulus of elasticity of 7075 is about 1/3 of that of 1018.

I could always make both and test them, but this has to be something very common... though because it has intrinsic commercial value it may not be freely available.

Anyway thanks!

[fabconv]

yes, cosmosworks in solidworks

[Ed from NY]

Student edition $128 (need proof of sorts), good for 12 months. EULA and limitations here http://www.engr.udel.edu/help/downlo...ulastudent.txt I think the functionality is equivalent to the one in the Premium edition -- I'm not a student.

Economic Stimulus Package edition is equivalent to the Standard edition. This is meant for people "in transition" to help them upgrade their skills. It is free, but expires after 90 days.

Regular versions: Standard, Professional, Premium. About $4K for the Standard and $8K for the Premium. May be able to negotiate better with your rep. Annual maintenance is said to be around $1K. These figures are per seat.

The Standard version only has what they call "express simulation" the full blown simulation comes in the Premium package. You can see the product matrix here http://www.solidworks.com/sw/mechani...are-matrix.htm

Looks like pretty amazing software if you are making money on it, not so good if you are a weekend warrior

Any other suggestions?

Thanks!

[keebler303]

What you want is finite element analysis. Not aware of any freeware, maybe you can get a demo of Abaqus or similar?
Is this a one time thing or will you need this often?
Exactly what loads are you looking to model?

I can do basic stuff and I have a friend who does it for a living, PM me if you want to farm it out for a nominal fee.

Matt

[samco]

would this work?

http://caelinux.com/CMS/index.php?op...tpage&Itemid=1

sam

[Ed from NY]

Originally Posted by keebler303 What you want is finite element analysis. Not aware of any freeware, maybe you can get a demo of Abaqus or similar? Is this a one time thing or will you need this often? Exactly what loads are you looking to model? I can do basic stuff and I have a friend who does it for a living, PM me if you want to farm it out for a nominal fee. Matt

Hi Matt, thanks for the offer. Half the fun is getting there though, so if you just give me some pointers it would be very cool

I need to calculate the loads. This is a replacement for a desktop mill transmission. This plate is to keep the motor shaft and spindle true. I'm expecting some shimming on the motor side of the plate, which would translate into point loads -- me thinks.

I have a small static load on the motor shaft from stretching the belt. The Gates design guide gave me 12lbs on the tight side and 5 lbs on the slack side.

Then there are the dynamic loads and it is all a big SWAG, including loads related to changes in the spindle load and loads related to things running eccentric as none of the elements is balanced.

In practice I was just thinking of putting 4 perpendicular forces on the 4 holes closest to the square hole (that is where the motor plate gets attached) and 4 reaction forces at the holes next to each corner.

Since all dimensions and shaft distances are within the same order of magnitude I was just going to vary those 4 vectors from plus and minus 100 to 1000 lbs static to introduce some torsion; and perhaps do the same dynamically at 10000 cycles per minute and see what gives.

Sorry if all of this seems very iffy and I'm not using the right technical terms, but I'm not a mechanical engineer. Anyway if you have any tips let me know. I'm making this up as I go along and about the only thing I have on my side is that I enjoy it

Originally Posted by samco would this work? http://caelinux.com/CMS/index.php?op...tpage&Itemid=1 sam

Hi Sam!

This looks like exactly what I'm looking for. It seems that learning it will be a one month project in itself though

I may get itchy and start milling :lol:

[keebler303]

I like to learn how to do stuff too. You didn't answer my question whether its a one time deal or if you have lots of parts to model. That would obviously influence your decision to buy an FEA package and learn how to use it. Realistic finite element modeling is hard to do, and even harder to do it right. Not something you learn in a few hours on a saturday afternoon.

I can do a "crappy" simulation using solidworks for cheap (free). If you want something legit, it takes lots more time and effort.

The lowbuck solidworks simulation (that I have access to) is extremely limited (to the point I never use it) but it might be good for a comparison. The loads and restraints are crappy approximations of real life and it can't do dynamic modeling.

With that said, if you send me the models and a sketch of the loads you want to apply, I will play around with it a little for you. PM me for my email.

Matt

[fidia]

I think COSMOS Works is the best solution if you havn't used and FEA software before. It is user friendly and can provide very good results. Could you PM me.