Getting Started with Electric Vehicle Design

Written By: Dave Martin
  • 2/22/2022
  • Read Time : 3 min.
Electric motor.

Designing electric vehicles in CAD presents several advantages over designing traditional internal combustion engines. These include:

  • Electricity has lower fuel costs than gasoline.
  • Electric motors have lower mechanical complexity, so they require less maintenance.
  • Electric engines are cleaner because they have zero emissions, and therefore are better for the environment and climate change.

Gasoline shortages, higher fuel costs, and environmental concerns have led to higher interests in electrification for automobiles, aircraft, underwater vehicles, and unmanned aerial vehicles (drones). Advances in battery technology have extended the range of electric vehicles to make them a viable alternative to traditional engines. These factors have resulted in more companies exploring the design of electric vehicles.

I first worked on electric vehicles with Amazon Prime Air in 2014. It was significantly different from my time at Boeing or Lockheed Martin, where we had design manuals developed over decades and previous product lines to guide us in new designs. With electric vehicles didn’t have those advantages.

“Think outside the box” is a cliché, but sometimes you don’t even have a box. So, how do you design a new electric vehicle? Here’s one approach.

Designing for Electric Vehicles

Let’s look at using computer-aided design (CAD) tools, techniques, and processes in a framework for electric vehicle design.

Decompose requirements into design specifications. Product development begins with requirements. For electric vehicles, these include mission, range, capacity, operating conditions, reliability, and more. We decompose top-level requirements into subsystem requirements and then into design specifications. We translate requirements into numerical values like weight, volume, lengths, charge, power, and current. Tools like Mathcad and relations in Creo Parametric assist in this step via engineering calculations.

Use Top-Down Design techniques. Batteries are the heart of any electric vehicle. You might start by laying out space claims for their volumes and the other major components. In an automobile, this includes the motor, transmission, converter, and charging system. In a drone, we have motors, propellers, avionics, and sensors. We can then design the vehicle’s structure.

Create the vehicle’s shape with surfacing tools. Composite materials, 3D printing, and advances in manufacturing allow us to create vehicles that are more aerodynamic, ergonomic, and aesthetically pleasing than the geometry of traditional vehicles. To design the vehicle outer mold line (OML), we can use:

  • Standard “technical” surfacing features like sweeps, blends, swept blends, and boundary blends.
  • Freeform surfaces, also known as “style” surfaces. These features consist of curves and surfaces that you create and dynamically manipulate in 3D space, designing by feel.
  • Subdivisional modeling, in which we start with a primitive shape like a sphere, cube, or cylinder, and then push and pull on the shape almost like modeling in clay.

Connect the batteries to the components they drive with 3D cabling harnesses. We can map out our network with block diagrams, circuit diagrams, and wiring diagrams in 2D with applications like Creo Schematics. Then we can use these logical references to drive the routing of our cable harnesses in our 3D assembly model.

Populate your vehicle assembly. In addition to standard 3D part models, we can create components using:

  • Sheetmetal design for thin-walled parts.
  • Lattices in additive manufacturing to reduce weight while retaining the necessary strength.
  • Libraries, like those found in Creo’s intelligent fastener extension (IFX), to place fasteners like screws, washers, and nuts quickly and easily.

CAD tools accelerate and simplify the design process for electrification.

Next Steps

Deloitte estimates a 29% compound annual growth rate for electric cars over the rest of the decade. The UAV market is expected to have a 16.4% growth rate by 2026. The market and demand for electrification provide enormous opportunities for product development organizations.

Are you interested in taking advantage of these trends to help your company’s market share? To find out more about how Creo can support your electric vehicle design, visit www.ptc.com/creo.

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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.