Ill-conditioned cross section general flexible beam

Hi,

I am modelling a beam in bending using a general flexible beam.

I want to give it a I (or H) cross section using the code below. However it keeps on giving me the same error:

The sectional properties computation is ill-conditioned for the specified cross-section. This might be due to overlapping or very close edges. Resolve this issue in order to simulate the model.

CMat_I = [ 0.1      -0.05   % 1
           0.1     -0.2    % 2
           0.15     -0.2    % 3
           0.15     0.2    % 4
           0.1      0.2    % 5
           0.1      0.05   % 6
          -0.1      0.05   % 7
          -0.1      0.2    % 8
          -0.15     0.2    % 9
          -0.15    -0.2
          -0.1      -0.2
          -0.1      -0.05
          ]

[Star Strider]

What function is throwing the error?

Please post the relevant parts of your code.

[John D'Errico]

Please don't add answers just to make a comment. Moved to a comment, from Rafael:

"Well, its is just the simscape mechanics block general flexible beam that gives the error.

the error message is posted in the original question. So there is no other function involved apart from the general flexible beam. When I use a rectangular cross section it works, but for some reason this H profile gives an error when running the simulation but not when updating the cross-section preview.

The code that is relevant is also nothing more than the code in the original question. The matrix is used to define the cross section of the beam (like specified in the matlab documentation)."

https://nl.mathworks.com/help/physmod/sm/ref/generalflexiblebeam.html

[davide ambrosi]

I have the same problem with Extr_Data_Box function to model the cross section of the flexible beam. I somehow managed to resolve it by modeling a slightly opened profile: it's like the box profile but cutted, so it's an open line.

But I'd prefer to use the right profile, so I hope they'll solve this problem at MathWorks

Answer 1

[Steve Miller]

I just tested this extrusion profile in the General Flexible Beam block and it generated no warnings in R2022b. This may work in previous releases. The extrusion as defined does not look problematic at all, though, so I am surprised warnings were generated.

--Steve