Reducing design weight by 53 percent and resolving casting design problems easily before creating patterns or molds

About the customer

Etteplan Oyj is a global technology service company specializing in software, embedded systems, engineering solutions and technical communication. With extensive experience from successful additive manufacturing (AM) projects, Etteplan’s AM experts embrace virtual design validation, enabling them to explore and optimize part
geometry, performance, manufacturability and process development.

Their challenge

Tasked by one of its clients, a renowned manufacturer of agricultural plants and equipment looking to enhance its products and improve the harvesting process, Etteplan revisited the design of a cast steel extension boom end of a tree harvester. This large, heavy part is designed to resist static and dynamic forces throughout its arduous working environment.

Working with its customer, Etteplan specialists chose Simcenter™ software simulation-driven design for manufacturing (DFM) tools to initially demonstrate the design development, manufacturing and physical testing of the optimized AM part’s durability. Then, the company reexamined the design so it could be manufactured via casting – a more affordable mass production process.

Simcenter is part of the Siemens Xcelerator business platform of software, hardware and services.

Left - Cast Option - final design.
Right - AM Option - final design. (Photo: Teemu Leinonen – LUT)

Our solution

Siemens Digital Industries Software tools were successfully applied in almost every step of the design development process from optimization to finalization. This workflow included a combination of implicit modeling and PolyNURBS for innovative geometry creation, producing organic shapes supported by lattice cores. Simcenter Inspire™ software and Simcenter Optistruct® software were used for finite element method (FEM) validation.

For the cast version, Etteplan reused the optimization runs but changed the manufacturing constraints used for the topology optimization. Leveraging the Simcenter Inspire Python application programming interface (API) scripting capability, the team developed a script that combined implicit modeling and PolyNURBS generation to import optimization results and resolve challenging geometry, enhancing the part’s castability. A quick solidification analysis using Simcenter Inspire Cast software was then performed to identify and correct potential issues such as areas of high porosity, ensuring the overall manufacturability of the final design.

AM option – TOP: Process simulation
BOTTOM: FEM validation

Results

With confidence in the simulations from using Simcenter tools, Etteplan successfully presented to its customer how the original part could be redesigned and redeveloped for additive manufacturing and casting. The AM option was a technology demonstrator for a customer new to the process. Although it was an expensive option for serial manufacturing, it clearly showed the power of AM to reduce weight by 66 percent, coupled with an exceptional fatigue performance (failing at six times original peak loads after 3.5 million cycles). Such exceptional durability achieved by the organic part geometry was due to a lack of any stress raisers acting as crack initiation points.

Although the optimized cast design revealed features known to be challenging during casting, such as wall thickness variations and corners, leveraging Siemens tools enabled engineers to easily resolve these problems early by adding material or making local adjustments as needed, long before patterns or molds were created. Even with adjustments made for manufacturability, the design achieved a weight reduction of 53 percent, demonstrating how tailoring the design optimization workflow to the chosen manufacturing method, enabled by Siemens solutions, delivers efficiency and performance.

“With Etteplan’s experience of real-world engineering with additive manufacturing, we are genuinely impressed by how the Simcenter simulation-driven design tools streamline the entire process,” says Erin Komi, additive manufacturing specialist at Etteplan. “The intuitive modeling features, extensive implicit toolbox, simulation and optimization capabilities and seamless workflow automation with Simcenter Inspire Python API have equipped us with everything we need to tackle challenging AM design cases.”

Cast option – TOP: Quick manufacturability check (casting solidification)
BOTTOM: Final FEM and fatigue analysis