Cadalyst MCAD Tech News #137
19 Jan, 2005Streamlining CAD/CAM With CAE
No longer just a tool for specialists, today's analysis technology can save anyone time and money
So you've got all sorts of CAD and CAM tools in your shop and you've seen the ways they've affected how you work as well as how you interact with your customers and
vendors — positively, I hope. Looking for a way to further increase your
productivity while optimizing your processes? If you haven't already done so, it may be time to consider integrating CAE (computer-aided engineering) tools into your
workflow.
Not all that long ago, CAE was relegated to the latter stages of the design and manufacturing (product development) process, all too many times as an afterthought. This is changing, though, on two fronts. First, realizing the potential payback in terms of reduced production time and getting it right the first time, many design and manufacturing organizations have moved CAE tools further forward in the development process. Some are even using them in the earliest stages of design, at the conceptual phase. Second, software vendors are getting better at integrating CAE with their CAD and CAM tools.
A major roadblock to CAE's wider acceptance has been the perception that only high-priced analysis specialists could understand and work with CAE tools. While specialists are indeed required for some of the high-end tools that perform complex analyses, many CAE tools now on the market require just some basic training and practice to become proficient in a relatively short time. Admittedly, all CAE tools require a technical mind, but you no longer need a doctorate in mathematics to run many types of analysis and simulation. Today, you really need only a familiarity with a CAE application's interface to create and load digital models, then review and interpret the results. Finally, computer hardware prices that continue to drop have helped CAE tools become more widely accepted and adopted because some of those tools can require a lot of computing horsepower when working with large assemblies or very precise engineering constraints.
Several types of CAE-related manufacturing applications are available for optimizing the use of materials, tools, shape and time by simulating and analyzing specific manufacturing processes. Here, however, we'll focus on what is probably the most common method for getting CAE into a manufacturing environment, FEA (finite element analysis) for designed parts and tooling. In a future column we'll discuss another major CAE arm, CFD (computational fluid dynamics).
FEA Fundamentals
Basically, FEA is a numerical technique for calculating the behavior of mechanical
structures. You can use it to calculate strength, deflection, stress, vibration,
buckling and other behaviors. Typical applications for FEA include minimizing
weight and/or maximizing the strength of a part.
With FEA, structures are divided into small, simple units, called elements. Although
the behavior of individual elements can be described using a relatively simple set of
equations, a large set of simultaneous equations is required to describe the behavior
of a complex structure. When it solves the equations, the system displays the
physical behavior of a structure based on the individual elements.
You can use FEA tools for innovating or optimizing mechanical designs. Optimization
is a process for improving a design that results in the best physical properties for
minimum cost. However, optimization using FEA tools can prove challenging. Because
each design variation takes time to evaluate, iterative optimization is
time-consuming. On the other hand, FEA tools can really shine when you're seeking new and
unique ways of designing things — the crucial aspect of innovation.
Making the Move to FEA
Before committing to any CAE tool, be sure it is compatible with your existing CAD
and CAM tools, the types of parts and assemblies you design, and your general
workflow. Keep in mind that no single CAE tool exists that will serve every need.
Some of your users will be interested in structural mechanical properties, while
others will concern themselves with thermal issues. Get input from as many groups
within your organization as are likely to benefit from CAE use.
Be sure to evaluate
CAE tools using your own parts and assemblies models, not just those supplied by the
vendors, so you can objectively determine which CAE tools best suit your needs in
your environment. And use the same parts and assemblies for each evaluation, so you
can see how the CAE tools compare under the same conditions.
Finally, a word of caution. Don't expect CAE tools to solve all problems associated
with all your parts. Like CAD and CAM tools, they should be used in conjunction with
experience and common sense to arrive at optimized and innovative designs.
Calculating return on investment when using CAE tools can be as complicated as
performing analyses on complex assemblies. However, you can probably count on
estimating ROI from time saved during the design process, lower materials costs,
reduced numbers of physical prototypes and ECOs, and possibly reduced
product-liability issues. CAE tools cannot perform miracles by themselves because
they still require a human element, but used correctly, they will likely improve your
workflow and provide tangible benefits.
