Ultimate concrete strain in M-N diagram

SOFiSTiK Teddy
1

Hello,

I’m creating some normal force / moment interaction diagrams with AQB, but I find that the maximum strain reached by the concrete in pure compresion is 1.6 o/oo instead 2 o/oo:

Design Forces and Moments

  •      SNo     N[kN]    Vy[kN]    Vz[kN]  Mtp[kNm]  Mts[kNm]   My[kNm]   Mz[kNm]  Mb[kNm2] e1,e2[o/oo]*

  •      1    -78071.8      0.00      0.00      0.00      0.00      0.00      0.00      0.00   **-1.60   -1.60***

  •      1    -77650.8      0.00      0.00      0.00      0.00   1073.37      0.00      0.00   -1.78   -1.39*

I’ve written the following code:

+PROG TEMPLATE urs:3
HEAD Variables of circular section

STO#F_CK 28
STO#D 2

END

+PROG AQUA urs:1
HEAD Cross section designed

ECHO FULL NO
ECHO MAT NO
ECHO SECT YES

NORM DC US NDC AASHTO-2014 COUN US unit 0

CONC NO 1 TYPE ACI FCN #F_CK GAM 0.0 FC 0.85*#F_CK TITL ‘Concrete’ $$
EC ((4700)*#F_CK^(1/2))
STEE NO 10 TYPE SACI 60 TITL ‘Reinforcing steel’ $ Fy = 420 MPa FU = 620 MPa

SECT 1 MNO 1 MRF 10 TITL ‘Section’
CIRC NO 1 R #D1000/2[mm]
LAY NO 1 TID M TYPE MIN MRF 10
CRF NO 1 R #D1000/2-70[mm] d 32.3[mm] A 24[-] DIST full

END

+PROG AQB URS:2
HEAD Normal force / moment interaction
ECHO FULL
CAPA NCS 1 TASK NM STAT UL

END

How can I change this ultimate strain?

Thanks and regards,
Gonzalo