Manufacturing

Inventor In-Depth: Functional Design Gets the Right Designs Done Faster

15 Apr, 2005 By: Kevin Schneider Cadalyst

Autodesk Inventor 10 incorporates intelligent tools that work the way engineers think


One of my earliest introductions to engineering was a grammar-school exercise in building a peanut butter sandwich. The teacher stood in front of us with a loaf of bread, a jar of peanut butter and a knife. The students were to give her instructions for assembly.

We told her to take out two pieces of bread. Next, we told her, "Put peanut butter on one slice."

Following directions, she picked up the jar and balanced it on top of a slice of bread. We hadn't suggested unscrewing the lid or using the knife. We thought this was hilarious, and silly as it was, the exercise was a lesson in one of the primary challenges in product design: abstraction.

The latest release of Autodesk Inventor, launched in March, tackles some of the long-standing constraints that technology has placed on engineers -- constraints that make design work abstract instead of intuitive. Specifically, Autodesk Inventor 10 includes more capabilities for functional design, tools that let engineers start with product performance to get to the right design. I'll review some of these features in this month's column.

Functional Design Works the Way Engineers Think
Take the handheld vacuum. Most likely an engineer conceived the whole first, including function, style and ergonomics: A vacuum that's small and lightweight enough to carry easily, powerful enough to operate at different angles and comfortable to grip.

Next, conventional design technology requires a step of abstraction -- like the instructions for building a sandwich. To use design software, the engineer must abstract his or her idea for the end product into elements such as geometry and features, the number of parts and how they might fit together.

This is not a very intuitive way to work. Users of 2D software spend a lot of time capturing ideas in AutoCAD and then tweaking lines, arcs and circles until calculations indicate the drawings should work. Then they build a prototype and fit the parts together to evaluate function. That's when they discover if the design works as intended. Often it's back to the drawing board.

Enter software capabilities for functional design. Functional design entails a more intuitive approach to design that's congruent with engineers' thought process. Functional design tools help engineers get past the limitations of geometric modeling.

Functional design capabilities are noteworthy because they describe how parts work and what they do, not just their dimensions and physical features. As a result, designs are active, not static; they have built-in intelligence to reflect the actual behavior of the parts they represent -- including the relationship to other parts.

Ultimately, functional design gives engineers the ability to begin the design process with the end-product's performance, and then define relationships among product components rather than their geometry. In functional design, torque and speed characteristics are built into a gear, and the first gear knows it must interact with another gear; it's not just a representation of a disk with a certain number of teeth of specific dimension.

Autodesk Inventor 10 Adds More Functional Design
If you've used Autodesk Inventor Professional, you've experienced functional design by working with tools for automated tube, pipe and wire harness design, and tools for built-in FEA (finite element analysis) from Ansys. Piping design capabilities incorporate user-defined styles, rules, and pipe properties, rather than simply tracing pipe placement (figure 1). FEA mesh and analysis is produced automatically from user-defined loads, revealing how parts perform based on actual characteristics.

figure
Figure 1. Properties are built into piping design elements to reflect their function.

The latest Autodesk Inventor family of applications includes new functional design capabilities. Autodesk Inventor 10 lets engineers simulate the motion or action of a product from within the design application. Engineers can create parts and assemblies based on real-world attributes, using drag-and-drop tools to quickly build 3D models without the abstraction required for parametric design.

  • Design Accelerator automates creation of parts and assemblies based on object properties rather than geometric descriptions. Tools for doing so include the Engineer's Handbook, a comprehensive online reference for engineering formulas and manufacturing; Mechanical Calculators for design and validation of mechanical systems, from weld and solder to fit and tolerance; and Component Generators, which incorporate user-defined conditions -- from power, speed, materials, and torque to working temperatures -- to address mechanical connections between assembly components.
  • Feature Generator lets engineers create parts by dragging and dropping shapes from a library of standard geometry that has built-in intelligence to reflect attributes such as speed, power, and material properties (figure 2). Using 3D Grips, users can edit parametric parts through drag-based action.

figure
Figure 2. Drag-and-drop standard components build a functioning assembly.

  • Autodesk Inventor Studio produces state-of-the-art rendering and animations within the Autodesk Inventor design environment for high-quality, photo-realistic renderings and animation of designs (figure 3).

figure
Figure 3. Animation capabilities within Autodesk Inventor help show a design's function.

Take Less Time to Get to the Right Design
Functional design allows engineers to start with the end-product's performance and move on to the relationships among product components. For example, functional design tools build torque and speed characteristics into a gear, and the drawing element knows it must interact with another gear -- it's not just a representation of a disk with teeth.

That means engineers spend less time trying to master modeling software to get a 2D idea into a 3D representation. Without the drafting tasks and abstract thinking required by conventional design, functional design is faster and more intuitive. Instant insight into components' interaction makes designers more productive: They can optimize designs as they work, modeling product quality and cost trade-offs and reconciling them quickly with fewer prototyping and refinement cycles to get to the right design.


About the Author: Kevin Schneider


AutoCAD Tips!

Lynn Allen

Autodesk Technical Evangelist Lynn Allen guides you through a different AutoCAD feature in every edition of her popular "Circles and Lines" tutorial series. For even more AutoCAD how-to, check out Lynn's quick tips in the Cadalyst Video Gallery. Subscribe to Cadalyst's Tips & Tricks Tuesdays free e-newsletter and we'll notify you every time a new video tip is available. All exclusively from Cadalyst!
Follow Lynn on Twitter Follow Lynn on Twitter


Latest News from Cadalyst Partners
Feed
The Infinite Resource: the case for GMO instead of organic farming   22 May, 2013

I have no desire to eat pesticides. I really don't. Actually when I was a child growing up in New Orleans, a "fog truck" used to come down our...More>>Read more It's Alive in the Lab blog posts>>

Feed
TERA Semicon Drives Its Own Destiny with CAD and PDM   22 May, 2013

When you read the history of TERA Semicon, you can see right away that the company has had a strong vision and direction from Day 1. The South Korean...More>>Read more PTC Creo blog posts>>

Feed
Excel Hyperlinks & Document Management Tricks   22 May, 2013

Do you have to keep track of a lot of different folders and files? Do you wish you peers could open the correct Revit file? Are you tired of having...More>>Read more BIMbuilder blog posts>>

Feed
SolidWorks Simulation Tips: Parameters and Design Studies   22 May, 2013

In my opinion, one of the most underutilized tools in SolidWorks Simulation is the Design Study.  Design studies allow you to easily set up a...More>>Read more SolidWorks Blog posts>>

Feed
Is This the All-in-One Bike Helmet of the Future?   22 May, 2013

For those used to cycling on busy city streets (NYC comes to mind), the need for swift reaction times could be compared to that of catching a fly...More>>Read more SolidSmack blog posts>>

Poll
What type of input device (besides the keyboard) do you use at your primary CAD workstation?
Standard mouse
Trackball mouse
Programmable mouse
3D navigation device
Pen/tablet
Multiple devices
Submit Vote




Considering Wide Format Printing Solutions?
Four FREE White Papers Available:






Subscribe Cadalyst Newsletters