abaqus stability limit - reinforced concrete

[Batzo]

Hi,
in order to calculate stability limit (of reinforced concrete):

Δt≈min⁡(Le/C_d )
C_d=√(E/ρ)

I have also steel rebars,
so what do you recommend in selecting E and ρ? to use only the concrete metirial properties?

I want to understand becuase i have two different materials

thank you!!!

 

[FEA way]

How do you want to model the reinforcement ? As discrete rebar (beam elements) ? Abaqus will calculate the stable time increment for each element separately and use the lowest value. In case of linear elastic material the formulas from your post apply.

 

[Batzo]

I want to model two models:
1. 3d solid elements for concrete with beam elements for rebar
2. Shell composite with rebars inside

And how does abaqus calculate the stable time in explicit calcution beyond the linear elastic point?

 

[FEA way]

Check the documentation chapter "Explicit dynamic analysis" (paragraph "Dilatational wave speed"). It explains how Abaqus calculates C_d.