Comments on: CAD for FEA in the GOOD old days http://lifeupfront.com/2009/05/04/cad-for-fea-part-2/?utm_source=rss&utm_medium=rss&utm_campaign=cad-for-fea-part-2 Getting ahead with CAE, direct modeling, and creative engineering Sun, 18 Jul 2010 02:39:32 +0000 hourly 1 http://wordpress.org/?v=3.0 By: Jeff Waters http://lifeupfront.com/2009/05/04/cad-for-fea-part-2/comment-page-1/#comment-4990 Jeff Waters Wed, 06 May 2009 12:12:26 +0000 http://lifeupfront.com/?p=591#comment-4990 Hello Harald, I'll have to consider your comments as I write the next piece! There is a spectrum of CAE usage from "early, rough trend" to "dead-on, .1% accuarcy against test data." I tend to personally lean towards the "early, rough trend" end of that scale in terms of overall value. In those scenarios, it's less likely that subtle differences between a simulation-ready and mfg-ready CAD model will matter. But when you get more to the other end of the scale where you are more using CAE as a validation tool, you are absolutely correct. Coincidentally, the modern solution for handling CAD in CAE will appeal to engineers at both ends of that spectrum. Hello Harald,
I’ll have to consider your comments as I write the next piece! There is a spectrum of CAE usage from “early, rough trend” to “dead-on, .1% accuarcy against test data.” I tend to personally lean towards the “early, rough trend” end of that scale in terms of overall value.

In those scenarios, it’s less likely that subtle differences between a simulation-ready and mfg-ready CAD model will matter.

But when you get more to the other end of the scale where you are more using CAE as a validation tool, you are absolutely correct.

Coincidentally, the modern solution for handling CAD in CAE will appeal to engineers at both ends of that spectrum.

]]> By: Harald Hermansson http://lifeupfront.com/2009/05/04/cad-for-fea-part-2/comment-page-1/#comment-4989 Harald Hermansson Wed, 06 May 2009 11:02:46 +0000 http://lifeupfront.com/?p=591#comment-4989 Hi, I'm eagerly waiting for part three, but dare make a comment already now: One of the most important objections to starting over with a simulation model from scratch instead of repairing an existing production CAD model is the risk that you do some mistake and don't end up with exactly the same geometry in the end, even if this should be a much simpler path to follow. And even if there is no such mistake made, there will be people suggesting the models are not equivalent. I've been working with CAE in different physical domains (FEA, CFD, CEM) for more than 20 years, and knows that there is much value in a simulation ready production CAD model, and that it can have a very long life (as long as the complete product life cycle actually). As it is now, people working with transforming raw CAD models into simulation ready models in these fields very often use different tools and methodology even within the same company, and does the same work three times over. It would be interesting to read your comment on that in the next part! Best regards, Harald Hermansson Hi,

I’m eagerly waiting for part three, but dare make a comment already now:

One of the most important objections to starting over with a simulation model from scratch instead of repairing an existing production CAD model is the risk that you do some mistake and don’t end up with exactly the same geometry in the end, even if this should be a much simpler path to follow. And even if there is no such mistake made, there will be people suggesting the models are not equivalent.

I’ve been working with CAE in different physical domains (FEA, CFD, CEM) for more than 20 years, and knows that there is much value in a simulation ready production CAD model, and that it can have a very long life (as long as the complete product life cycle actually). As it is now, people working with transforming raw CAD models into simulation ready models in these fields very often use different tools and methodology even within the same company, and does the same work three times over. It would be interesting to read your comment on that in the next part!

Best regards,

Harald Hermansson

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