Seismosoft | Earthquake Engineering Solutions

Hi everybody and congratulations for this great forum.

I'm using seismostruct 7 for some academical studies and i'm conducting pushover analysis on RC columns.

I'm using mander model for concrete but i see that the unconfined stress-strain curve does not drop to zero at a strain equals to the spalling strain.
I verified this by inserting two stress points: one in the most compressed fiber of core concrete, one in the most compressed fiber of cover concrete.

Can i somewhat model this behaviour correctly?
Do i need to use a previous version of seismostruct to solve this?

Thank you for your help,
Rob

Dear capitanhook,

Due to its Constitutive law, the Mander et al. nonlinear concrete model keeps a residual strength.

Dear Zoi,
thank you for the reply.

Does the criterion for the strength apply to a single fiber or to the entire element?
I already tried to use this method and i think it reduces the strength of the whole section, and this clearly led to unacceptable analysis results.

Dear capitanhook,

The performance criteria apply to all the fibres of the element.

So it is impossible in seismostruct to model the real phenomenon of spalling such that the RC section progressively loses strength (and stiffness),

isn't it?

Thank you again

Hi capitanhook,

The progressive loss of strength and stiffness of the section is effectively modeled by the constitutive stress-strain curve of the concrete material. All the SeismoStruct models for concrete feature a peak capacity, after which the strength reaches the residual strength.For more details see the Materials module and the relevant sections in help system and the users manual.

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