Light-Gauge Framing

Innovations in Curved Framing: From the computer screen to the job site

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Recent innovations to the light-gauge steel framing industry have followed a pattern of integrating design with production/fabrication. The creativity being exhibited by today’s designers has challenged the industry to find new solutions that are more efficient and affordable, while structurally accommodating these new, bold forms. This increased demand for curved and warped surfaces of all description has driven the metal fabrication industry to move to more automated processes that utilize 3-D computer modeling tools, CAD/CAM integration, building information modeling, and a full reliance on virtual modeling techniques to resolve conflicts and geometric irregularities before material reaches the job site. In addition, contractors/fabricators are invited into the process earlier to lend framing and material expertise as the designs are being developed rather than coming in after the design is finalized. This change will likely have the most lasting impact.

Integrating Design with Production/Fabrication
It is no longer unusual in this technology climate for designers to hand-off the 3-D computer models they have been developing directly to the fabricator for further refinement and development. This breakthrough in team integration is streamlining the transfer of information without the knowledge loss that often follows the translation of 3-D elements into 2-D documents. With a rectangular solid building design this wasn’t such an issue, but as the complexity of surface design has ratcheted up, clear communication has taken on new importance.

The 3-D computer model has become the conduit of this information/communication flow.Over the last eight to 10 years huge strides have been made in the convenient interface between design concept and modeling. No longer confined to the aerospace industry, 3-D computer models are taking the virtual construction“mock-up” to new heights. Systems that need to interface and fit together are test fit in the model. BIM processes utilize the 3-D computer model to resolve conflicts, called clashes, early in the process to save material, labor miscues and ultimately construction dollars.

Transition to New Processes
This idea of the transition that team integration has experienced was exhibited to full effect for the Walt Disney Concert Hall in Los Angeles,designed by Frank Gehry Partners. The Disney project was conceived during an era (the late 1990’s—seems like so long ago) when the primary way to curve structural framing elements was through the “stretch forming” process. This process, while effective, was not very affordable. In stretch forming, members are literally stretched and bent around a specific sized, custom-built form. The stretch forming process was used for the exterior framing for the concert hall. In order to make it affordable,the designers had to settle on a limited number of radii, to limit the number of custom forms needed to be built, and adjust the design to utilize only those radii.

With the bending innovations brought into the industry by companies like Radius Track Corp., Minneapolis, stud and track bending has become a more affordable option while retaining predictability and accuracy. Radius Track developed a new way of accomplishing on-site bending and shop-fabricated, pre-curved members. This approach uses calibrated crimps, or bends, in the web and/or flange of tracks and studs to precisely curve members to match any design intent. This innovation replaced the stretch form method with a more affordable and versatile approach. The interior framing utilized in the concert hall was no longer limited by pre-built forms, so a much broader range of radius options was now available to the designers with dramatic results!

Today, Radius Track’s bending technology—in just those last 10 years—has advanced to such a degree that the majority of surface framing systems including heavier structural stud and track elements can now be efficiently produced with larger pneumatic benders. These machines when coupled with the data extracted directly from 3-D computer models can bend (web) or crimp (flange) much heavier gauge material and much deeper sections. The ability to roll track(stretch it’s flanges, leg out) or crimp (compress it’s flanges, leg in) added the capability for compound bend/crimp or roll/bend configurations.This removed the final limitations on designers for all manner of compound-curved surfaces.

What You See is What You Get
With this full set of manipulation skills in hand, expertise and equipment now exist to produce complex, curved framing solutions limited only by the creativity of designers. But that’s not all. Add to this capability the ability to analyze and fine tune all manner of curved surfaces using software tools like Rhinoceros 3-D and Solid- Works, fabricators have emerged as leaders in multi-dimensional framing solutions.

This digital capability has provided the added value of making sure that what you see on the computer screen is what will end up on the job site. Tools that are integrating the computer model with the production process make this precision and consistency possible. Companies that have integrated design and fabrication data achieve the best results. One set of data makes for reliably consistent product.

The next step in automation and process refinement was the integration of the 3-D modeling software with the fabrication process. Radius fabricators at the forefront of technology have developed Computer Numerical Controlled systems which couple geometric algorithms with mechanical design technology to create abstract shaped steel studs and track. In simpler terms this is a method of transferring the data, extracted directly from their computer model, into an automated production process. This process integration ensures reliable and precise curved members that perform to the exacting standards of the 21st century marketplace for both structural and non-structural applications.

Data Extraction
Data extraction was probably not a term you often heard in a metal fabrication shop 10years ago. The Digital Age has led to new service offerings including BIM design and 3-D computer modeling. In the walls and ceilings marketplace, some fabricators have set them- Innovations in Curved Framing From the computer screen to the job site By John Klockeman, FAIA, LEED AP selves apart with the ability to be a bridge for contractors currently without BIM or other 3-D modeling capability. As an outsourced team member, these BIM-enabled fabricators bring the unusual combination of light-gauge steel framing expertise and 3-D modeling savvy— gift-wrapped with a BIM bow. In today’s climate, this agility finds an eager audience.

A Demanding Marketplace
The demands of the market and innovative design challenges have driven today’s leading metal fabricators to recognize market needs and respond to them with innovation and creativity.As in any industry this is the hallmark of success. The well-publicized Rensselaer Polytechnic Institute-Curtis R. Priem Experimental Media and Performing Arts Center project (pictured above)in Troy, N.Y., is an excellent example of the innovation required by challenging design solutions. This project, designed by New York City-bases Nicholas Grimshaw & Partners, required the prefabrication of light-gauge steel framed panels to construct a dramatic inner, wood-clad cocoon.

It was accomplished with the complex curvature of the finished surfaces and the panelization structure. Building panels like these off site, to be later erected into position would not be feasible without 3-D computer modeling and the precision it can deliver when skillfully engaged. RPI-EMPAC required a timeline an methodology that challenged the team to be creative and innovative. Once the procedures were finalized and the panels built, it was the modern advancements and reliable quality assurance that delivered.

Finally, it is critically important to remember that machines do not produce the quality these projects and customers seek—people do. Innovators that are unafraid to explore new technologies and techniques make the difference. The people and companies that are undeterred by challenges have pushed the metal fabrication industry to new value in the marketplace. In this economic arena, value is the bottom line.

John Klockeman, FAIA, LEED AP, is design manager at Radius Track Corp., Minneapolis.