Altair Optimizes 3D-Printed Structures for Complex, Lightweight Designs

June 1, 2015

Ryan Gehm

Altair expects to better support the use of additive manufacturing (AM), or 3D printing, by releasing new OptiStruct solver capabilities for topology optimization. The company claims this new technology is the first tool developed specifically for designers of lattice structures.

3D printing is capable of manufacturing hollow shapes with complex external geometry using lattice structures. OptiStruct now extends topology optimization to assist in the efficient blending of solid-lattice structures with smooth transitional material volume, according to Altair. Lattice performance can be studied under tension, compression, shear, flexion, torsion, and fatigue life. The technology provides CAE analyses for optimal and structurally efficient material distribution.

Topology optimization is particularly well-suited for 3D printing, according to Altair, because it tends to create freeform, organic structures that can be difficult or impossible to construct using traditional manufacturing methods.

“3D printing brings new structural freedom to product design, allowing more complexity in shapes and topology and the efficient production of customized products while accelerating the manufacturing process, since no tooling is needed,” said Uwe Schramm, Chief Technical Officer at Altair. “Topology optimization maximizes this design freedom, enabling complex free-form structure development, seamless individual designs, a shorter design process, and optimal 3D-printed structures.”

Altair is working with partners such as Materialise NV, a Belgian provider of AM software and 3D printing services, to enable more efficient data transfer. Lattice structures can contain hundreds of thousands of lattice cells, proving to be a challenge for conventional STL file transfer. Software packages like 3-Matic- STL from Materialise focus on improvements of a given lattice component to accommodate the various requirements of the 3D printing process, creating support structures where necessary.

Instead of simply applying lattice structures to existing geometry, OptiStruct enables the designer to identify the best material placement and lattice structures, according to Altair. Optimization identifies where material is needed in a design—and where it is not required—prior to placing and optimizing lattice.

OptiStruct optimizes lattices in two phases. First, it applies standard topology optimization, allowing more porous materials with intermediate densities to exist. Then, the porous zones are transformed into explicit lattice structures with varying material volume. In the second phase, the dimensions of the lattice cells are optimized. The result is a structure with solid parts plus lattice zones with varying volumes of material.

Lattice zones could enable the successful development of products that require characteristics beyond just stiffness. Some applications, for example, may need to consider buckling behavior, thermal performance, or dynamic characteristics. With OptiStruct, users can manipulate material density based upon the result of an optimization process, comparing stronger vs. weaker, or solid vs. void vs. lattice designs.

“OptiStruct’s lattice capability represents the first step towards integrating smart materials with unique properties in products,” said Ming Zhou, Vice President of Software Development at Altair. “Continuing research and development will explore directional behavior and smooth blending of varying lattice cell layouts to take advantage of exotic material characteristics that could bring innovation to various applications.”

Part of the Altair HyperWorks CAE suite, OptiStruct is used for topology, topography, size, and shape optimization.

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