ChefChristian
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posted on 1/3/07 at 08:05 AM |
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Purchase CAD program
I am have finished my chassis design on paper and need to move it to a CAD to FEA/stress analyze it. I would like to purchase someones backup copy or
slightly older version of Autodesk Inventor, Solidworks or SolidEdge. I am not doing the bearshare or kazaa thing. Cant afford the $,$$$ they want
for a new copy. Please email me with anything that you may have.
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miegru
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posted on 1/3/07 at 08:42 AM |
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I bought Alibre (www.alibre.com) some months ago. I paid 1400 Euro for the most extensive version and am happy with it. You can download the full
software for free from their site to try it out.
Have no experience with other cad software so cannot comment on its relative performance. Alibre themselves quite simply claim to be a cheaper
alternative to Solidworks.
The FEA tool that comes with Alibre (Algor) however is only for parts, not for assemblies. A frame is something that you can create as one a part with
some creativity so should not be a problem. An upgrade to the full FEA functionality however will cost me more than 5000us$ and I don't want to
spend that kind of money.
Am very happy with alibre customer service. Have desktop and a laptop and Alibre doesn't have any problems giving me multiple keys for one
licence. So I can install it on multiple computers.
Hope the info helps. If there are other uses who have experience with both Solidworks and Alibre I am interested in their opinions. I also
didn't want to go illegal and Solidworks was simply too expensive for me. But am curious if that was a wrong type of saving.
Rgrds,
Mies.
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britishtrident
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posted on 1/3/07 at 02:26 PM |
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Pointless using FEA unless you know what you are doing with it, unless you really understand the types of constraints loads and elements to use, the
results you get will have no more value than random numbers picked from the phone book.
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Doug68
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posted on 5/3/07 at 07:28 AM |
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For the user who doesn't have access to software other ways then I would highly recommend Rhino at
US$1K it's the best value for money out there and is written by Autodesk dissidents so has an Autocad sort of feel which may or may not interest
you.
To do stress analysis you do not need any of these tools though as there are good free linear stress analysis tools available. Personally I use
Framework and other people on the forum have used a thing called GRAPE.
All of these packages can give you silly results though, you have to understand the principles enough so that 1. you can ask the right question of the
system and 2. you can recognize when its giving you garbage back.
One of the hardest parts with all of this is getting sensible load values to put into your models and what those should be is a combination of what
you're going to use it (the vehicle) for and research you will need to do to satisfy yourself that you understand the problem.
For 2D CAD its hard to go past SolidEdge's drafting environment as it's Free!
[Edited on 5/3/07 by Doug68]
[Edited on 5/3/07 by Doug68]
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ChefChristian
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posted on 8/3/07 at 06:30 AM |
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Thanks for the info. Rhino is cool but very artsy. $1,000 is still steep. I downloaded solidworks 2D and it works well for what it is except I
would still like to stress it.
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Doug68
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posted on 8/3/07 at 07:50 AM |
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I've used SolidEdge for my design but I still can't stress it in SolidEdge as I don't have access to the full version of FEMAP.
Without paying megabucks (or going to KAAZA) you are not going to get what you want.
You can however, do what you're asking for with 2 or 3 tools as described previously.
Thats about it I'm afraid.
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violentblue
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posted on 8/3/07 at 02:20 PM |
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I don't know id autocad would work for your purposes, but Bricscad is perfect clone, and is much less expensive.
we have it on our secondary systems in the engineering office I work at.
a few pics of my other projects
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86barettaguy
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posted on 15/3/07 at 10:14 PM |
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quote: Originally posted by britishtrident
Pointless using FEA unless you know what you are doing with it, unless you really understand the types of constraints loads and elements to use, the
results you get will have no more value than random numbers picked from the phone book.
Actually, as long as you pay attention and do not do just about everything wrong it's going to provide you with some information, although not
exact.
Let's say you want to test your chassis. You restraint the rearmost bar and apply forces to the front corners to twist the structure. Then have
a look at how much your structure moves. Change the design and repeat the exact same analysis once again. Comparing the results, you can now determine
whether or not you have made an improvement, for this particular load case.
FEA is not as difficult as engineers want you to think it is, but then again, unless you know what you're doing, don't use it for stress
analysis of something vital... As an example, I had a hard time modelling a problem we had at work with parts breaking until I realized that there
were two slightly different load cases going on depending on which point in the test cycle you were looking at. Just goes to show that you cannot be
certain until you have actual test data and a really good understanding of what is going on.
As for softwares... ProEngineer and ProMechanica are pretty good CAD and FEA softwares, but I'm guessing they're a bit pricey for a legal
copy. Most companies tend to charge quite a bit for licenses and I think that in general, they need to be renewed yearly and are not included in the
purchase of the software. There are student editions available for some CAE softwares like Solidworks, so maybe that's a way to get there?
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