Non linear hinge-section EP

[Tuctas]

  When defining a non linear hinge in a steel member and choosing the option the parameters of the hinge model (diagram) to be calculated automatically by the program (by checking in the window of “parameters” the limit rotation and limit moment, see screen capture “limit rotation”), then the calculated values of the diagram are different when the section is set to be with elasto-plastic analysis comparing to the same standard section (see attached screen capture “rotationHEA200” and “rotationHEA200EP”. This concerns only the yielding rotation and not the yelding moment, as the later is calculated identically

  Thank you    

[Tuctas]

  Anyone that can tell why is there such a difference between the automatically calculated yielding rotation when the EP section is used?

[Pawel.Pulak · Accepted solution]

It is related to dividing the element with hinge into smaller calculation elements. In such case the calculation of hinge properties is not based on the length of whole bar but on the single calculation element. It is an unjustified effect analyzed by developers.

You have noticed it on EP section because members with elasto-plastic sections are by default divided into smaller calculation elements - see the additional calculation node numbers visible on your first screen capture.

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Regards,

[Tuctas]

  Thank you for the answer. You are absolutely right, It didn't come to my mind directly.

  Actually there is no much meaning to use EP sections together with non-linear hinges isn't it? The EP sestions are used for distributed plasticity and non-linear hinges for concetrated plasticity.

[Pawel.Pulak]

Yes, defining non-linear hinge on the member with EP section corresponds to defining concentrated plasticity and distributed plasticity simultaneously on the same member.

Regards,