#Façades | @Petersen_Museum @aZahner @3DSAEC
Zahner is an internationally acclaimed engineering and fabrication company best known for its highly crafted architectural metalwork.
One of Zahner’s recent projects, the Petersen Automotive Museum in Los Angeles, designed by Kohn Pedersen Fox (KPF), demonstrates how supply chain integration can help move complex buildings quickly to completion.
KPF principal Trent Tesch brought Zahner onto the project during its early stages to prove to the owner that the proposed façade — a complex swirling structure of stainless steel ribbons—would indeed be possible to fabricate.
The fabrication team began and lived in a 3D world from the beginning.
“We took the architect’s surface information and built out all of the parts based on their original 3D model,” says Mr. Shannon Cole, Zahner Senior Project Engineer.
The project called for the design of 26-foot long unitized pieces that spanned from one anchorage point to another.
“For the structural design, we laid out a wire frame and provided this to our structural engineer for analysis,” Cole explains. “This wire frame was then used to fabricate not only our scope, but the structural steel as well. Because [the architects] did their detailing in separate software, the next step towards actually building this was to bring it into our CATIA model as a cross-check to verify that they were providing the required geometry.”
Cross-checking geometry enabled Zahner engineers to accurately verify that each of the more than 300 unique ribbons were correct.
The team relied on CATIA to create knowledge patterns that could be adapted for each element. The CATIA software also enabled Zahner engineers to export and manufacture the parts.
As Cole explains, “From CATIA we had basic scripts that would export all the files to our shop in .dxf format. That’s what gets cut on our factory floor.”
While the process of designing each ribbon was fairly complex and required some design expertise, the fabrication and installation process was much simpler.
“Essentially, we’re building it twice,” explains Cole. “We build it once using CATIA, and then we build it again on our shop floor. So it’s important to get everything right when we build the design in the model, so that the fabrication and installation processes flow smoothly.”
This process of “building it twice” is executed in a managed structured engineering practice, similar to what you might find in the the construction field.
“We had a limited number of senior engineers who worked on this at the conceptual phase, and when production began we were able to bring in additional junior engineers who could smoothly transition into producing the additional system design work.
The model allowed them to quickly release a lot of parts to production based on the rules and knowledge patterns that were used,” Cole says.
The model kept installation simple as well.
“One of the most fantastic things about this is that there were a hundred parts unique to each and every one of these panels, but the way everything fit together for these elements, the parts checked each other,” Cole says.
The installation team used jigs to ensure the location of critical points on the product.
From there, the finish skins simply had to have their corners come together correctly to demonstrate accuracy.
“Everything went up in the field fantastically well,” Cole says.
He attributes the accuracy to reliance on and trust in a 3D model.
“Even when there were problems, the model allowed us to identify them early, we knew exactly what we were getting into at every step.”