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nTop

Replacing spacecraft supermaterial with high-performance lattice

Applications

Key Software Capabilities

  • Simulation
  • Topology optimization

Summary

An engineering research team at NASA used nTop software to develop a unique lattice structure that allowed them to replace an expensive, long-lead time material in a benchtop laser measurement system with a safer, less expensive material—without compromising performance.

About: The NASA Goddard Space Flight Center is the nation’s largest organization of scientists, engineers, and technologists dedicated to building spacecraft, instruments, and new technology to study the universe.

  • Industry: Aerospace
  • Size: Large
  • Location: Greenbelt, Maryland
  • Application: Latticing


The project

Material selection for a laser benchtop system

Scalar field derived from thermal simulation used for optimization

The baseplate of the laser benchtop system tends to deform from the heat of the laser, affecting the accuracy of measurements. This issue is relevant to a wide range of laser, LiDAR and photonics systems used in aerospace. The original design was made from beryllium: a supermaterial used for its stiffness and thermal properties. But it is also expensive, its dust is hazardous, and only a few shops can machine it for aerospace applications.

The challenge

Change material, maintain performance

Thermal and structural properties of unit cells NASA evaluated to replace solid beryllium

The NASA team wanted to replace beryllium with a safer, less expensive material without compromising performance. The chosen material was A6061-RAM2, a general-purpose AM aluminum alloy. To accomplish this, the team wanted to create a lattice network that could achieve similar deformation performance with an equivalent elastic strain similar to beryllium, an equivalent stress less than beryllium, and mass targets within ±10% of beryllium.

You’re taking a cheaper and relatively weak material and asking how to make it outperform an extremely expensive advanced material that’s 33% lighter. You have five constraints and it’s a multi-physics problem. This is really difficult to solve.

Alex Souk

Senior Mechanical Design Engineer

NASA Goddard Space Flight Center

The solution

Systematic latticing with computational design

Using the full complement of lightweighting tools in nTop, including topology optimization, the as pro R&D team were able to optimize the differential cap for several load cases at a time. The result was a new design that was light enough to deliver a potentially race-winning difference in performance. It was also optimized for additive manufacturing, eliminating expensive tooling costs.

The results

  • 1 part

    Consolidating 40 components

  • 9%

    Weight reduction

  • 7.8 seconds

    Faster performance over 24 hrs

  • £30,000

    Savings in tooling

Before we started using nTop, we could only simulate one load case at a time. If you're doing each load case within separate simulations and then adding them together, it takes forever, but more importantly, you end up with a heavy, suboptimal component. nTop solves this problem, which was crucial to the outcome of my dissertation project.

Alex Tully

Junior Lightweighting Engineer

as pro engineering

Why nTop?

The as pro R&D team chose nTop because it is capable of optimizing for multiple load cases simultaneously, which was critical for this application. The team was also attracted to nTop’s fast processing speeds for complex design work and automated workflows that feed directly into finite element analysis (FEA) of the given load cases.

Reusable workflows

The research team saved a great deal of time with nTop’s reusable workflows. To begin, they created a workflow to feed loading conditions into the FEA tool for simulation. This same workflow can be repurposed for any combination of load cases, eliminating the need to create a new workflow for every simulation and significantly reducing the engineering time required to set up similar design projects.

Reusable workflow enables rapid iteration of designs.

Explore variants quickly

Accelerating prototype development is essential for endurance racing, a sport dedicated to continuous innovation. With nTop, as pro engineering can test, correlate, and validate their design concepts with a 10x faster feedback loop. Iterating on new ideas more efficiently gives them (and their hypercar clients) an edge when it comes to developing race-winning designs.

Simulation of early iterations of the final differential cap design.

Eliminate tooling costs

The differential cap was specifically designed for additive manufacturing, which removes the high costs of tooling in the previous magnesium cast design. The cost to manufacture the original part totaled approximately £30,000 ($39,362) between the cost of the material, the mold, the fixturing and machining. The cost of 3D printing the topology optimized cap would be £7,000, for a net savings of £23,000.

Optimized differential cap design to be additively manufactured.

Conclusion

Lightweighting tools in nTop enabled a team of hypercar design specialists to develop a significantly lighter part that could deliver a race-winning difference in performance.

Until carbon fiber additive manufacturing catches up, we’ve nearly reached the limit of how far we can push the lightweighting of this part. There's currently no performance left on the table. The next step is applying this process to as many other parts on the car as possible.

Andrew Shedden

Director

as pro engineering

The real value with nTop is its ability to accelerate our dev cycles so we can test and validate ideas as quickly as possible and go around the development loop again and again, quicker and quicker, until we can’t push our lightweighting any further. nTop is key to keeping us and the next generation of hypercars at the forefront of lightweighting technology.

Andrew Shedden

Director

as pro engineering

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