ETABS 15 Enhancements
A new modified Darwin-Pecknold concrete model has been added to the nonlinear layered shell. This model represents concrete compression, cracking, and shear behavior under both monotonic and cyclic loading, and accounts for crack rotation.
Time-dependent creep, shrinkage, and stiffness behavior has been added for the CEB FIP-2010 and ACI 209R-92 codes and for user-defined curves.
Notional size for time-dependent creep and shrinkage behavior is now specified on the section properties rather than at the material level, and can be automatically computed or user-defined.