Opinions

Some Thoughts On Simulation

I am in Pune and just attended the Siemens PLM Connection today. I attended as press, not as a Siemens PLM Solution Partner. I learned a lot of stuff about the company, its products and its customers. I will need some time to synthesize all this information which I hope to do over the next few days.

The Siemens simulation solutions were highlighted a great deal in a number of presentations today. As I watched and listened I began thinking about simulation from a higher level. It dawned on me that the Siemens PLM simulation solutions like Nastran, Femap, etc, are actually not solving users’ problems. The same goes for the simulation solutions from every other CAD and analysis vendor out there today.

Before you think that I’ve lost it, I need to explain myself a little more here. When I say that today’s simulation solutions do not solve users problems I am referring to the fact that these solutions merely report the problem and quantify it, but leave the fixing to be done by the user. For example, take a FEA analysis on a part. A user sets up loads, defines boundary conditions, assigns material properties, etc. and then tells the simulation software to do its thing. The thing that the simulation software actually does is it that it tells the user whether the part will fail or not, where and how it will fail and gives him a host of other data which the user is left to study and decide what to do next. The software does not automatically tweak the geometry of the model for the user and reanalyze for failure and continue to do so till a fail safe design has been reached.

What I am trying to say is that the simulation software merely reports the symptoms of a disease but does not cure it. You still need an experienced analyst to decide which parts of the geometry of the part need to be changed and then start the analysis process over again till a fail safe design is reached. My point here is the the real problem of a user is not to determine where and how a part will fail. His real problem is to come up with a fail safe part, which is something that today’s Simulation software do not do. They merely aid the user in arriving at a fail safe part.

I am actually talking about part optimization here. Imagine a situation wherein you design a part, run an FEA analysis on it and the software actually goes ahead and adds ribs in places where it feels they are required for the part not to fail. The end result of such an operation will be changed geometry and not just a bunch of stress and strain values, factor of safety numbers or a picture showing a part in different colors. Similarly, the software could automatically weaken certain parts of the model where it can so that you save on material and/or manufacturing cost. For example, it could remove ribs or reduce their quantity and/or size.

I understand that analysis takes a lot of time and making it into an iterative process will only take it longer. But I am looking at this with the future in mind. What do you think? Do you think engineers in the future will continue to work like how they work today. If you do FEA analysis do you stop at the point where a part becomes fail safe or do you tweak the geometry where you can to see if you can arrive at a better and more efficient design. Do you think computers will be fast enough and software will be smart enough to start with an initial design from a user and take it forward from there on? Is this already possible to an extent? I’d love to know what you think.