Generative Design: A New Way of Designing

Written By: Dave Martin
  • 8/15/2022
  • Read Time : 6 min
Deliver your best designs in less time with generative design software from PTC.

Generative design is an automated method of creating Computed Aided Design (CAD) geometry for part and assembly models using machine learning. Rather than defining the shape using feature-based or direct modeling methods, a user specifies the design space (like an envelope, including areas to be preserved or excluded), operating environment conditions, materials, and manufacturing constraints. An algorithm then computes one or more potential solutions. The user can then filter down the results to select an optimal choice. Generative design is faster and, in many ways, more reliable than traditional iterative human-driven methods.

What Makes Generative Design Better?

Generative design and closely related topology optimization tools have been available for several versions in Creo. Let’s look at four aspects that make generative design different and better than traditional CAD workflows.

You’re building requirements into the design. All products start with requirements. The top-level requirements are decomposed into subsystem requirements, which are then distilled into component requirements. Even though we may know the structural requirements for a part or a subassembly, in the past, those requirements weren’t validated until the design was complete. With generative design, we set up our design by applying load cases to our model. This ensures that the solution meets the criteria from the beginning.

The manufacturing method informs the design. With typical workflows, parts are designed, validated using simulation and analysis tools, and are then handed off to a process engineer to assess if the part can be built using subtractive or additive manufacturing. With generative design, we add manufacturing criteria to the optimization study. These include:

  • A build direction for parts that will be 3D printed
  • 2D or 3D parting line for mold-injection parts
  • Linear extrude for parts that will be milled

This assures the solution can be manufactured with the appropriate method.

You generate multiple concepts quickly. Product development is always constrained by schedule. Products can never get to market fast enough. Usually during the initial design phase, a handful of potential concepts are created. With the help of machine learning, multiple concepts can be generated in less time than it takes a human to create a single concept.

The resulting model can be modified by the user. The part model created by generative design results in B-rep (boundary representation) geometry. This is the same kind of geometry produced in the subdivisional modeling workflow for surfacing. This geometry can be modified with standard parametric features or direct modeling tools such as the Flexible Modeling Extension.

The Generative Design Workflow

A study to optimize a model with generative design can be set up in minutes. The general process is as follows:

  1. Set up your design space. This involves your starting geometry, which is a body that represents the limit of volume for your model. You can also use bodies to specify volumes that must be preserved during the study and volumes where geometry is not allowed.
  2. Define your load cases. These represent the operating environments that your model must survive. It’s easy to define your constraints and loads.  
  3. Specify your design goals. This is typically a target mass or volume fraction of the original design space.
  4. Add your constraints. These include the manufacturing constraints listed above as well as geometry constraints like symmetry and factors to create thinner or thicker regions and reduce webs.
  5. Select materials. Creo currently allows up to 10 materials in a study.
  6. Apply the study settings to control the time and resources used.
  7. Run the optimization.
  8. View the results.
  9. Select the design you want and create the model geometry. You can also tessellate the final results for 3D printing.

The speed of this process is a game changer for companies on the leading edge.

Can Generative Design Help You?

Generative design is a proven concept that can help you create lighter parts in less time so you can get to market quicker. Explore more of generative design's potential to help your product development teams here.

Innovate Faster With Generative Design and AI

Explore how generative design capabilities can enable your engineers to create optimized designs in less time.

Tags:
  • CAD
  • Connected Devices
  • Creo
  • Aerospace and Defense
  • Automotive
  • Electronics and High Tech
  • Industrial Equipment
  • Oil and Gas
  • Generative Design

About the Author

Dave Martin

Dave Martin is a Creo, Windchill, and PTC Mathcad instructor and consultant. He is the author of the books “Top Down Design in Creo Parametric,” “Design Intent in Creo Parametric,” and “Configuring Creo Parametric,” all available at amazon.com. He can be reached at dmartin@creowindchill.com.

Dave currently works as the configuration manager for Elroy Air, which develops autonomous aerial vehicles for middle-mile delivery. Previous employers include Blue Origin, Amazon Prime Air, Amazon Lab126, and PTC. He holds a degree in Mechanical Engineering from MIT and is a former armor officer in the United States Army Reserves.