While designing or engineering a component for a spacecraft, the crucial challenge is weight optimization. And it can’t come at the expense of component strength or performance. Materialise Manufacturing worked together with the engineering division of Atos, a global leader in digital services, with the aim of re-inventing a titanium insert that is widely used in the aerospace sector to transfer high mechanical loads in structures like satellites. With a cleverly optimized design produced through Metal 3D Printing, the new titanium inserts are just one-third of the initial weight, with some improved properties added in.
Inserts in Sandwich Structures
These inserts are typically used as mounting points, to attach devices to satellites. Such inserts are often highly loaded, lifting large and heavy structures. That means they have to exhibit a great strength-to-weight ratio: it’s a part that has to have high specific strength and rigidity but at a minimal weight. The inserts are co-cured with the composite structure sandwich panels that typically are used in aerospace structures. The inserts transfer the load to the panel through an adhesive.
Classical inserts are commonly constructed in aluminum or titanium in a brick-like shape, as they are manufactured by machining. They are completely solid filled, which makes them high in mass and costs. In addition to the material costs, heavy components also raise the operational costs for the spacecraft on each launch.
Metal 3D Printing, however, can address those concerns — while still allowing for the use of the same materials, aluminum and titanium.
Design Optimization with Additive Manufacturing
The engineers faced the challenge to improve by far traditional concepts. The design was addressed to cover all space requirements, from conception phase to manufacturing. Atos’ expertise in aerospace engineering and structural simulation, helped to design this new component both in the outside and in its interior, enhancing its overall performance.
With Additive Manufacturing, the interior space of objects can be hollowed out or designed with lightweight structures, using material only where necessary. Engineers at Materialise and Atos first got to work with reducing material usage in the interior of the part. Using the advanced techniques of topology optimization and lattice structured design, the team reduced the insert’s mass from 1454 grams to 500 grams.
Besides weight reduction, the team also resolved thermo-elastic stress issues with the original design. As these inserts are installed during the curing process of carbon fiber-reinforced polymers, they are subject to thermo-elastic stresses. The optimized design has reduced vulnerability to these stresses and improved load distribution, resulting in an increased lifetime for the inserts.
What would 66% mass reduction mean for cost control in your industry?
When you machine away material from a block to produce complex parts, much of the metal you paid for is going to scrap. There’s a costly imbalance between the weight of the metal you purchased and the metal that constitutes your final “flying” component. That’s what we call the Buy-to-Fly Ratio. Read the free whitepaper “Buy-to-Fly Ratio: Cutting Costs with Metal 3D Printing”, and discover how Metal 3D Printing can help with the production of complex parts.