FEA Optimization

. . . All kidding aside, automated FEA optimization is a very impressive trick.  The basic concept is this:

1. Start with some idea of what your structural part should look like.  Leave plenty of room for improvement.
2. Input the part into FEA.
3. Set some optimization goals (like a maximum permitted stress).
4. Let the computer progressively remove material to create the lightest part possible.
5. Adjust to create a practical part (make sure it can be manufactured)

FEA optimization is very impressive for several reasons.  First, the computer can run through many more iterations than any human.  It gets the chance to really refine the part down to the narrowest margin.

Second, the computer creates some very interesting solutions.  As humans, we are often constrained by our own preconceived ideas of how to design a part.  The computer is only constrained by mathematics.   This often leads to inspirational solutions that humans may not conceive on their own.

It also leads to a lot of garbage.  Because the computer is fine with solutions like a plate of steel 1 micron thick.  Or a plate that looks like swiss cheese.  Mathematically, it still works.  So we need to apply additional constraints and FEA experience to guide that wayward computer.  Ensure that it reaches practical solutions.  Much of the skill in automated FEA optimization goes into this practical approach.

Tony Abbey of NAFEMS  wrote a series of articles on this subject.  They cover the nuts and guts of the different techniques.  And the pitfalls of each approach.  Worth a read.  Enjoy!

In Part 1 of this series of articles Tony dives a little deeper into the background of Topology Optimization and attempts to give some insights into what controls we can exert on the process to improve the relevance to our design goals.

The basic numerical approach behind the SIMP method is shown, together with provisions for mesh independency and checkerboarding.

In Part 2, Tony looks at two other important techniques; evolutionary methods and level set methods.

A wide variety of methodologies are currently used within topology optimization, as it is a very rapidly developing discipline. Over the next few years there will many new developments with additional methods, or combinations of methods. It will be intriguing to watch the new products that this activity spawns.

In the previous articles in this series, we looked at the various Topology Optimization methods used in commercial FE Analysis. In this article, we look at robust design solutions and methods used to align the final optimized design with available manufacturing techniques.