engineer

How obtain tension strain concrete(σt0) in damaged plasticity model in ABAQUS?

hello engineers

i need help about concrete damaged plasticity

fo example :

if Compressive stress (Fu)= 51.2 MPa

and tension stress (σ t)=0.3 x 51.2^(2/3)=4.136

1)why (σ t) is 2.36 in picture(uploaded)?

2)what is tension strain ? and how? i cant understand.

i cant obtain εt = total tensile strain.

how obtain εcr ?

please help