comparison with hand calculation of a simple beam

Dear Karamba team,

I am enjoying myself pretty much in using karamba in the daily structural related task. What I have found these days is that the stress value always exceeds than what it should be, therefore I did a small verification by comparing with hand calculation.

As a consequence, stress values appear to be displayed with ca. 100x higher values than those from hand calculation in the specific case as attached, while deformation values be quite close. Would someone give me a helping hand to understand this?

environment:

windows 7, 64bit

Rhinoceros 5.0 (5.1.30129.1756)

Karamba 1.0.3

Regards,

Bunji

Replies to This Discussion

Permalink Reply by Fred Becquelin on June 8, 2013 at 7:36am

from the manual p 46 :

The utilization of cross sections as displayed by the BeamView (see section 6.6.8) is the ratio of actual stress and yield stress.

Permalink Reply by Fred Becquelin on June 8, 2013 at 8:43am

Yes sorry I didn't check your files... obviously 1800% seems a little bit high :o

Permalink Reply by Karamba3D on June 8, 2013 at 11:12am

dear bunji,

when I open your definition I get a maximum utilization of 18.0%. Maybe the problem has to do with the windows local settings. In some countries (like e.g. Germany) '.' separates thousands and ',' separates the decimals. The regional settings can be checked in 'ProgramSettings/Region and Language/'; select the tab 'Formats' and then 'further settings'.

The reason why the Karamba result deviates from your hand-calculation is that the fillet radius of the IPE600 is not (yet) included when calculated with the 'I-profile'-component. When you select the IPE600 from the cross section table the results will be identical.

clemens

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