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Re: Special case of plotting a 3D function

  • To: mathgroup at smc.vnet.net
  • Subject: [mg50811] Re: [mg50795] Special case of plotting a 3D function
  • From: "David Park" <djmp at earthlink.net>
  • Date: Wed, 22 Sep 2004 00:11:26 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

I made this plot of this by laying a contour plot on a cylindrical surface
using DrawGraphics. Anyone who wants a copy of the notebook that made the
plot may contact me.

David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/

From: Fernando Ronci [mailto:fernandoronci at hotmail.com]
To: mathgroup at smc.vnet.net

Hi,

In Mathematica 5, how can I 3D-plot the diagram of normal forces of a
horizontal semi-cylindrical axisymmetical shell of a given length ?
The cross section of the shell is a semi-circle and the equation that
gives the normal force at every point of the surface is:
N = p . (x / r) . ( l - x) . sin(alfa)
where x and alfa are the two variables as follows:
x goes from zero to the length of the horizontal semi-cylinder (15
meter for example) and alfa goes from zero to PI radians (because it's
a semi-circle). Also, p is the external load, r the radius of the
semi-circle and l the length of the shell, but they're not relevant
because they're constants.
By looking at the above equation, the graph that represents the normal
forces N throughout the semi-cylinder is a 3D-surface that I want to
plot offset (or aligned, better said) to the semi-cylinder along its
length.

Then, I need to plot the same graph for a 15-meter-long horizontal
parabolic shell, instead of a semi-cylindrical one. The equation that
gives the normal forces throughout this new shell is different than
the equation of the semi-cylindrical shell, but it's got two variables
too. Again, my concern is to do the 3D plot "aligned" to the parabolic
shell.

To sum up, I'll highly appreciate if someone can tell me how to plot
these two equations (representing a 3D surface) aligned to a
semi-cylinder and parabol respectively.
Lastly, these two shells are different and so are the plots.

Thank you,

Fernando Ronci
E-mail: fernandoronci at hotmail.com




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