4.15.1.5. Damage2pΒΆ

nDMaterial('Damage2p', matTag, fcc, '-fct', fct, '-E', E, '-ni', ni, '-Gt', Gt, '-Gc', Gc, '-rho_bar', rho_bar, '-H', H, '-theta', theta, '-tangent', tangent)

This command is used to construct a three-dimensional material object that has a Drucker-Prager plasticity model coupled with a two-parameter damage model.

matTag (int) integer tag identifying material
fcc (float) concrete compressive strength, negative real value (positive input is changed in sign automatically)
fct (float) optional concrete tensile strength, positive real value (for concrete like materials is less than fcc), \(0.1*abs(fcc)\) = \(4750*sqrt(abs(fcc))\text{ }if\text{ }abs(fcc)<2000\) because fcc is assumed in MPa (see ACI 318)
E (float) optional Young modulus, \(57000*sqrt(abs(fcc))\) if \(abs(fcc)>2000\) because fcc is assumed in psi (see ACI 318)
ni (float) optional Poisson coefficient, 0.15 (from comparison with tests by Kupfer Hilsdorf Rusch 1969)
Gt (float) optional tension fracture energy density, positive real value (integral of the stress-strain envelope in tension), \(1840*fct*fct/E\) (from comparison with tests by Gopalaratnam and Shah 1985)
Gc (float) optional compression fracture energy density, positive real value (integral of the stress-strain envelope after the peak in compression), :math:6250*fcc*fcc/E` (from comparison with tests by Karsan and Jirsa 1969)
rho_bar (float) optional parameter of plastic volume change, positive real value \(0=rhoBar< sqrt(2/3)\), 0.2 (from comparison with tests by Kupfer Hilsdorf Rusch 1969)
H (float) optional linear hardening parameter for plasticity, positive real value (usually less than E), \(0.25*E\) (from comparison with tests by Karsan and Jirsa 1969 and Gopalaratnam and Shah 1985)
theta (float) optional ratio between isotropic and kinematic hardening, positive real value \(0=theta=1\) (with: 0 hardening kinematic only and 1 hardening isotropic only, 0.5 (from comparison with tests by Karsan and Jirsa 1969 and Gopalaratnam and Shah 1985)
tangent (float) optional integer to choose the computational stiffness matrix, 0: computational tangent; 1: damaged secant stiffness (hint: in case of strong nonlinearities use it with Krylov-Newton algorithm)

The material formulations for the Damage2p object are:

  • 'ThreeDimensional'
  • 'PlaneStrain'
  • 'Plane Stress'
  • 'AxiSymmetric'
  • 'PlateFiber'

See also here