Damage2p - OpenSeesWiki

# Damage2p

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.

 nDMaterial Damage2p \$matTag \$fcc <-fct \$fct> <-E \$E> <-ni \$ni> <-Gt \$Gt> <-Gc \$Gc> <-rho_bar \$rho_bar> <-H \$H> <-theta \$theta> <-tangent \$tangent>
 \$matTag integer tag identifying material \$fcc concrete compressive strength \$fct optional concrete tensile strength \$E optional Young modulus \$ni optional Poisson coefficient \$Gt optional tension fracture energy density \$Gc optional compression fracture energy density \$rho_bar ptional parameter of plastic volume change \$H optional linear hardening parameter for plasticity \$theta optional ratio between isotropic and kinematic hardening \$tangent optional integer to choose the computational stiffness matrix

The material formulations for the Damage2p object are "ThreeDimensional" and "PlaneStrain"

## NOTES

1. Admissible values: The input parameters vary as follows:

 \$fcc negative real value (positive input is changed in sign automatically) \$fct positive real value (for concrete like materials is less than \$fcc) \$Gt positive real value (integral of the stress-strain envelope in tension) \$Gc positive real value (integral of the stress-strain envelope after the peak in compression) \$rhoBar positive real value 0=rhoBar

2. Default values: The Damage2p object hve the following defualt parameters:

 \$fct = 0.1*abs(fcc) \$E = 4750*sqrt(abs(fcc)) if abs(fcc)<2000 because fcc is assumed in MPa (see ACI 318) = 57000*sqrt(abs(fcc)) if abs(fcc)>2000 because fcc is assumed in psi (see ACI 318) \$ni' = 0.15 (from comparison with tests by Kupfer Hilsdorf Rusch 1969) '\$Gt = 1840*fct*fct/E (from comparison with tests by Gopalaratnam and Shah 1985) \$Gc = 6250*fcc*fcc/E (from comparison with tests by Karsan and Jirsa 1969) \$rhoBar = 0.2 (from comparison with tests by Kupfer Hilsdorf Rusch 1969) \$H = 0.25*E (from comparison with tests by Karsan and Jirsa 1969 and Gopalaratnam and Shah 1985) '\$theta = 0.5 (from comparison with tests by Karsan and Jirsa 1969 and Gopalaratnam and Shah 1985) \$tangent = 0

## Development Team

This code has been Developed by: Leopoldo Tesser - Dept. DICEA - Univeristy of Padua - Italy,

contact: leopoldo.tesser AT dicea.unipd.it

## References

Tesser L.,"Efficient 3-D plastic damage model for cyclic inelastic analysis of concrete structures", Report of the University of Padua, Italy, 2012. (soon available at paduareserach.cab.unipd.it)

Petek K.A., "Development and application of mixed beam-solid models for analysis of soil-pile interaction problems", Ph.D. dissertation, Univerisity of Washington, USA, 2006