The general types of boundary models such as *Neumann boundaries*
or *Cauchy boundaries* are managed in the same way as standard
volume models. The difference the model developer has to keep in
mind, is the reduced dimensionality of a boundary element in a higher
order of space. Thus a model developed in the one-dimensional space
can not just be copied for usage as a boundary model for
two-dimensional problems because the points of the extracted boundary
interfaces are defined in the two-dimensional space. Therefore the
discretization of the model differs slightly from the one-dimensional
case. Fortunately, the basic implementation of a boundary model does
not make any difference to the standard volume model. Again, the
residual vector and the Jacobian matrix must be defined by the model
developer. Using the Input & Control Interface the boundary model can
be mapped onto a definite boundary. During the simulation process
AMIGOS evaluates the analytical boundary model and writes the
calculated values to the global stiffness matrix that has to be
solved finally.

1998-12-11