03
May
06

### Torsion Beam

Here is an exaggerated example of a beam being twisted. The following code is based on Stephen Timoshenko’s analytical solution. The color represents the equivalent (Von Mises) stress where red is high stress and blue is low stress.
```(* runtime: 12 seconds *) a = b = 2.0; L = 10; T = G = 1; J = 16/3a^3b(1 - 196a/(b Pi^5)Sum[n^-5Tanh[n Pi b/(2a)], {n, 1, 200, 2}]); k = T/(G J); phi = 32G k a/Pi^3Sum[1/n^3(-1)^((n - 1)/2)(1 - Cosh[n Pi y/(2a)]/Cosh[n Pi b/(2a)])Cos[n Pi x/(2a)], {n, 1, 10, 2}]; tauyz = -D[phi, x]; tauxz = D[phi, y]; tauxy = sx = sy = sz = 0; f[x_, y_, z_] := Module[{}, {s1, s2, s3} = Eigenvalues[{{sx, tauxy, tauxz}, {tauxy, sy, tauyz}, {tauxz, tauyz, sz}}]; sv = Sqrt[((s1 - s2)^2 + (s2 - s3)^2 + (s3 - s1)^2)/2]; {x - k z y, y + k z x, z, {EdgeForm[], SurfaceColor[Hue[2(1 - sv/0.029)/3]]}}]; << Graphics`Master`; DisplayTogether[Map[{ParametricPlot3D[f[#a/2, y, z], {y, -b/2, b/2}, {z, 0,L}, Compiled -> False], ParametricPlot3D[f[x, #b/2, z], {x, -a/2, a/2}, {z, 0, L}, Compiled -> False]} &, {-1, 1}], ParametricPlot3D[f[x, y, L], {x, -a/2, a/2}, {y, -b/2, b/2}, Compiled -> False]];```

Advertisements

#### 0 Responses to “Torsion Beam”

1. Leave a Comment

## Welcome !

You will find here some of my favorite hobbies and interests, especially science and art.

I hope you enjoy it!

Subscribe to the RSS feed to stay informed when I publish something new here.

I would love to hear from you! Please feel free to send me an email : bugman123-at-gmail-dot-com

• 555,424 hits
Advertisements