Please see the ATENA Theory Manual for detailed descriptions of the two material models - Chapters
2.1 Constitutive Model SBETA (CCSbetaMaterial)
and
2.2 Fracture–Plastic Constitutive Model (CC3DCementitious, CC3DNonLinCementitious, CC3DNonLinCementitious2, CC3DNonLinCementitious2User, CC3DNonLinCementitious2Variable, CC3DNonLinCementitious2SHCC, CC3DNonLinCementitious3).
Normally, we recommend to prefer the NLCem2 model, however, there are situations where SBETA is better.
A few differences that come first into my mind:
- SBETA is only Plane Stress, NLCem2 can be used for Plane Stress and Plane Strain
- multiple tensile softening functions choice in SBETA (usefull e.g., for simplified FRC modelling), including the Hordijk law used in NLCem2 (use NLCem2 User to define your own softening function(s))
- more options to define tensile-compressive and compression-cracking interactions and shear behaviour in NLCem2
- differences in compressive response (e.g., more advanced confinement modelling in NLCem2)