Initial conditions, Type=stress

*Initial conditions, Type=stress, <option>`
<element set>, <ic parameter 1>, ..., <ic parameter n>

Specify the initial values of initial stress at the integration points of an element or element set. Use one of the following options:

• Homogeneous

  use this option to prescribe a homogeneous distribution of initial stress for a particular element set. The command line takes the following form:

  *Initial Conditions, Type = stress, Homogeneous

  <element set name>, sigma_{xx,0}, sigma_{yy,0}, sigma_{zz,0}

• Geostatic
  Use this option to assign an elevation-dependent initial stress field to all members of a given element set. When a geostatic stress is prescribed for a particular element set, the stress in the vertical direction \(h\) (assumed to be the \(z\)-direction in 3-D and axisymmetric models and the \(y\)-direction in 2-D models) is assumed to vary piecewise linearly with this vertical coordinate. The command line takes the following form:

  *Initial Conditions, Type = stress, Geostatic

  <element set name>, h_1, sigma_0(h_1), h_2, sigma_0(h_2), K_{x,0}, K_{y,0}

  \(K_{x,0}\) and \(K_{y,0}\) are the lateral stress coefficients.

• User

  Use this option to specify the use of a user defined subroutine to define the initial stress field:

  *Initial Conditions, Type = stress, User

  The required user routine is described here.