Gurit is present throughout the advanced composite value chain, from upstream structural engineering, to materials, processes, and testing, and downstream, delivering prototypes and fully finished manufactured parts.
Overcoming Environmental Challenges with Advanced Engineering
The Te Ahi Tupua sculpture measures about 12 meters tall with a diameter around 6 meters. The inner and outer spirals are made up of groups of tubes with interconnected chevron plates. Four panels featuring traditional carvings are inlaid into the gaps within the sculpture. Initially, this was designed using steel, however concerns at the manufacturing stage lead to a reassessment of the materials to be used. The highly corrosive environment of Rotorua due to the geothermal activity presented potential issues with the longevity of the piece.
“It was interesting to see traditional Maori carving features represented using the modern technologies of 3D printing and composite materials,” said James Ledingham, Composite Structural Design Engineer at Gurit. “This created some unique challenges at the connections between parts which required careful analysis and verification via physical testing to produce a design that was both structurally sound and true to the artistic intent of the sculpture.”
The organic nature and complex curvature of the structure suits the layered nature and drapability of composites materials. Traditionally, costs associated with the molds and tooling needed to construct composite structures would be prohibitive, but the advent of additive manufacturing has enabled their use in many more architectural applications.
Around a thousand interlocking pieces were 3D printed and assembled, then wrapped in woven carbon fiber to form the curved tube structure. Gurit joined the project to confirm material quantities and verify that the required composite strength was achievable in order to withstand applied structural loads including the effects of high wind and earthquakes.
Leveraging Simulation to Validate Structural Integrity and Minimize Cost
A simulation-based solution was imperative since much of the stiffness is generated by the sculpture’s interconnected nature, resulting in very complex load paths. Using Altair HyperWorks software, Gurit was able to model and accurately interpret the bending stresses to derive the stiffness of the structure. A laminate optimization was then run with the objective to minimize mass. The Altair software weighed cost criteria and maximum deflection factors to help Gurit arrive at the optimal project result; a laminate structure that meets strength requirements, minimizes mass and cost, and maintains a simple, easy to build design.
Features like the auto-meshing and composite fiber orientation mapping in Altair HyperMesh™ allowed Gurit to quickly and accurately model the geometry and simulate the loads and stresses on the structure.
Now in the final stages of manufacturing, all involved in the project are excited for the Te Ahi Tupua sculpture to take its place at the gateway of the town. Incorporating New Zealand’s cultural history, unique geography, and technical innovation, the sculpture stands to embody the absolute best of Rotorua, past, present, and future.