Today, The FabricArchitect looks at Fabric Structures and the letter D. I could have mentioned the Denver Airport (that’s me on the right walking on the roof) or dealing with dirt but I thought I would focus on the fun part:
The first step in designing a fabric structure is to create a form with sufficient pre-stress or tension to prevent it from fluttering like a flag or sail.
How do you do that?
Understand the forms.
The three basic forms associated with tensioned fabric structures are the hypar (hyperbolic paraboloid), the cone, and the barrel vault.
The hypar, or simple saddle, is often a square or rectangular form in plan that in elevation is a series of high and low points in which the columns are located along the perimeter.
Mast- and Point-supported structures is where internal columns are used to support the membrane are cone or conical forms.
Arch- and Frame-supported structures, in which the membrane is supported by a rolled compression member are barrel vaults.
The second step of the design process is to determine the boundaries of the tensioned fabric. The fabric is either continuously clamped to frames, walls, or beams or attached to columns and anchor points with membrane plates with adjustable tensioning hardware.
Once the primary points have been determined, the next step is form-finding (you will learn more on form finding when we get to the “F’s”).
Today, Fabric Structures are primarily done on the computer using sophisticated softeware in combination with with programs like Autocad and SketchUP.
Designing fabric structure on the computer is only as good as the people working the computer. My favorites are Chris Griffin and Andrea Zamora at FabriTec. They got their drawing templates set up so you can take a basic sketch and get REAL revised plan and 3 d drawing rather quickly.
Don’t believe me?
The last step in the design process is analysis of the structure’s response to loads, including dead loads and live loads such as snow, wind, people, and equipment. Sould have told you about “analysis” in chapter A but I will talk some more about when I get to “E”.
It wasn’t that long ago when one use to hear about a “circus in town” .The circus was a traveling business. One would drive around the country and rent a space and set up a tent. You would charge admission and hopefully make more than what you paid for rent and then move on. Today, these nomadic structures are much smaller and are part of short term villages as popup tents for flea markets, farmers markets and tail gate parties. Their are fewer moving large temporary structures around but one can still see them for Fashion Shows ans Special Events. The lost art of the Circus in Town is left to Big Apple Circus and Cirque du Soleil.
What’s the future?
Three quick suggestion to my Venture capitalist.
A Tent for Teens. Teens like to go to Malls to see and be seen but they have nothing to do. What if you leased a space in the parking lot of a mall and created a place for teens to go that isn’t a club or a movie and charge a fee. If you build light, they will come.
A Tent for Gamers. Traveling tournamet for Video Gamers in a unique tent. They will see the tent and know “the tournament is in town”. To enter the tournament, there is a fee. Have game? They will pay to play.
A Tent for Seniors. Wouldnt it be great if Seniors could find a place to meet and get some special treatments. Music, food and medical services could be made available by sponsors.
Got an idea for using a pre-engineered tent or custom fabric structure to make money? Let’s talk.
All this design and development requires great details. Mies van der Rohe is acknowledge for saying “God is in the Details” and that can certainly be said about fabric structures. It’s just steel, fabric and cables but everything is exposed and working out the details is your key to success. We will talk about membrane plates in “M” but when it comes to details, start at the base. The base plates are the “feet” of your fabric structures. Moment or pin connected, they can be easily forgotten. If you are making pin connected bases, a beautiful pin will be a give a great impression. Anchor bolts at bases can be exposed , covered or below grade and covered. Its all part of the architecture.
You want to see some thing real cool?
Check out this link on details.
Its from the School of Architecture of Barcelona.
Lets talk about “E” next time.