<ISOTROPIC> isotropic_sum

Description

This object defines the yield radius as \(R = \sum_i R_i~\), where \(~R_i\) are values given by an unlimited number of standard <ISOTROPIC> models (other than isotropic_sum).

Syntax

The syntax is the following:

*isotropic isotropic_sum \(~\,\) *-isotropic <ISOTROPIC> \(~\,\) … \(~\,\) *-isotropic <ISOTROPIC>

Example

The example hereafter is an alternative to the linear_nonlinear standard definition using the more flexible isotropic_sum object:

***behavior gen_evp
 **elasticity isotropic
      young 260000.
      poisson 0.3
 **potential gen_evp ev
  *criterion mises
  *isotropic isotropic_sum
   *-isotropic linear
     R0 100.0
     H  1000.0
   *-isotropic nonlinear
     R0 0.0
     Q  100.0
     b 0.1
***return

giving the following equation for yield radius R function of the cumulative plastic strain \(p\):

\[R(p) = R_0 + Hp + Q(1 - e^{-b p})\]