Beam deflection stresses

Hey.

I am trying to calculate the bending moment and stresses when deforming a simple beam element. I am trying to use Kangaroo and Karamba3d together, but I cannot seem to make it work. Know that the Large Deflections module resets the results each time, so I am not sure how to use this.

Basically I want to see the stresses from bending/moving a controlpoints of a simple element.

I have attached a screen shot, the definition file and a .3dm test file.

I hope that somebody have an answer.

Best regards Rasmus

Attachments:

Capture.JPG, 214 KB
test.3dm, 45 KB
test.gh, 20 KB

Replies to This Discussion

Permalink Reply by Rasmus Holst on November 27, 2012 at 1:55am

Finally I want both. In order to validate my structure I want to check the strength (stresses from bending moment) and the deformation of the structure. By adding the bending moment from the large deformations(M=-EI/R) to the ones by small deflections (Karamba3d), I can not use the deformation calculation from Karamba3d.

I mean, the pre-stressing should result in a higher stiffness and thereby a smaller deformation.

Permalink Reply by Karamba3D on November 27, 2012 at 7:17am

Hi Rasmus,
pre-stressing or post-tensioning is used to introduce a self-equilibrating force distribution in a structure. By doing this you can e.g. avoid that ropes get flaccid or concrete cracks under working loads. In those cases pre- or post-tensioning results in a stiffer structure because it postpones non-linear effects.
In the case of the arch above pre-stressing does not change the stiffness of the system.

Best,

Clemens

Permalink Reply by Rasmus Holst on November 25, 2012 at 3:22am

Hi Daniel.

That would be nice, the thing about combining the two engines (Kangaroo and Karamba) for me is to look at the effect of the pre-stressing from bending, I can easily calculate the stresses from the curvature afterwards and then add them to output from Karamba, but then I do not get the true displacement output. So I will try and calculate the strain instead and at that as pretension in Karamba.

Also I read one of your posts about getting the reaction forces out as well from Kangaroo, that would be nice. :)

Thanks.

Rasmus

Permalink Reply by Rasmus Holst on November 29, 2012 at 3:10am

Okay that makes sense. Thanks a lot Clemens. You have been very helpful.

Best regards Rasmus