<POTENTIAL> associated

Description

This potential takes the same form as the gen_evp potential described above, but alters the criterion to be associated with the hardening mechanisms input. The criterion form can be written:

(454)\[f = f_{cr}({{\bf p}},\ \ten \sigma-\Sigma{{\ten X}}_i) + \Omega_i(R) + \Sigma\Omega_i({{\ten X}}_i)\]

where \(f_{cr}\) is the criterion as calculated by the <CRITERION> object entered after *criterion. There are some additional restrictions with this potential type due to numerical or physical restrictions.

The resulting behavior includes a nonlinear yield zone radius dependence on the \(R\) isotropic variable. A dependence also is introduced with the kinematic hardening variables on the isotropic radius. As the kinematic back stress is increased (through monotonic straining) the yield radius is decreased thereby increasing the Bauschinger type effect (reduced yield on reversal).

Syntax

The syntax understood by this potential is summarized below:

**potential associated [ name ] [ *flow <FLOW> ] [ *flow <RATE_VAR_FLOW> ] [ *criterion <CRITERION> ] [ *kinematic <KINEMATIC> [name] ] [ *kinematic <DIRECT_KINEMATIC> [name] ] [ *isotropic <ISOTROPIC> ] [ *var_coefs ] [ *store_all ]

Example

The example given for the gen_evp potential may be run with this potential by only changing the potential name to associated.

***behavior gen_evp
  **elasticity isotropic
     young 260000.
     poisson 0.3
  **potential associated
   *criterion mises
   *flow norton_k_variable
        n  7.0
   *kinematic nonlinear
        A1  15000.0
        Bp     30.0
   *isotropic constant
        R0 130.0
   *K non_linear_recovery
        R0  200.
        A     0.0
        Rp    1.0
   *parameters
        A       7.8125e-3
        N       1.0
        vdot0   1.0e-11
        sig0    1.0
        m       1.0
        B01     1.0
        B02     1.0
 ***return