From: Charles Greenlaw <cgreenlaw(--nospam--at)speedlink.com>
Date: Thu, 08 Apr 1999 12:40:11 -0700
Nels, there is an analog method that I saw in a fine documentary film on
Spanish architect Antonio Gaudi, who designed irregular dome roofs on
columns of sporadic location and tilt.
As you note, the situation can be turned over and modeled as a real,
physical model, as a tension structure of flexible elements and proportioned
weights, where all these elements find their way into the position of least
energy. The film showed such a model, and I got the idea that Gaudi scaled
the geometry and tensions that resulted and built to it. Here, you may be
working with a different array of what's fixed, and what's variable to
experiment with. But "modeling" is still the essence of it.
In the theater, I kept thinking, "Jack Barrish has got to see this." When
the lights came on, there was Jack and a party of his friends. Jack died
recently, and memorial services are Saturday in Sacramento. He was president
of our local SEAOC Section in 1952, and of the statewide SE Assn in 1970.
Charles O. Greenlaw, SE Sacramento CA
At 10:34 AM 4/8/99 EDT, you wrote:
>I'd like to find a thorough reference on catenaries. Specifically, I need to
>be able to determine the shape of a flexible tension element as a function of
>the load that it supports.
>Actually, I'm working on strengthening an existing unreinforced stone dome
>roof. The profile of the neutral axis of a dome as a compression element,
>regardless of its shape, has the shape, inverted, of a flexible tension
>element supporting the same load.