Seismosoft | Earthquake Engineering Solutions

Good morning,
I am trying to model a simple column element (0.1m x 0.1m x 1.2m) with a single bar (d16) to perform a Static time-history analysis.
I'm simply imposing a vertical displacement (0.01m, in tension and then return to zero). The base node is fixed and x,y and rz are restrained on the top. I'm using three elements (FB) to discretize the column.
My problem is: when the reinforcement is perfectly centered I can complete the load cycle without issues, but if I move the reinforcement of 0.001m in any direction the analysis stops almost immediately. Do you have an explanation for this behaviour?
Thanks in advance,
Angelica

We would guess that the concrete tensile strength is zero, right? The problem with the rebar eccentricity is that in the case of tension the eccentric rebar causes a moment around the element axis that cannnot be equilibrated by any other monitoring point of the section, since they have zero tensile strength.

Seismosoft Support

Many thanks, I had not thought about this issue.
Angelica