Error in Modelica Mechanics

[modelica-trac-importer]

Modified by dietmarw on 1 Jun 2010 08:51 UTC
There seems to be a problem in Modelica.Mechanics.MultiBody.Parts.BodyCylinder

The error is in the calculation of r_CM which is set to

r_CM[3]=Modelica.Math.Vectors.normalize(r)*length/2 

but must be

r_CM[3] = (r + r_shape) / 2;

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Reported by erik.aberg on 1 Jun 2010 08:38 UTC
One of our customers suspects that there is a bug in Modelica Mechanics.

Best regards,
Erik Åberg

Original message:

The problem is in Modelica.Mechanics.MultiBody.Parts.BodyCylinder

The error is in the calculation or r_CM which is set to
r_CM[3]=Modelica.Math.Vectors.normalize(r)*length/2

but must be

r_CM[3] = (r + r_shape) / 2;

---

Migrated-From: https://trac.modelica.org/Modelica/ticket/373

[modelica-trac-importer]

Modified by dietmarw on 1 Jun 2010 08:51 UTC

[modelica-trac-importer]

Comment by otter on 26 Jul 2010 19:35 UTC
Fixed in c1a246c.

The correct formula is:
rCM = r_shape + Modelica.Math.Vectors.normalize(lengthDirection)*length/2

The same error was present in BodyBox and was also corrected.