It should be read or edited using a copy of Mathematica or MathReader. The line below identifies what version of Mathematica created this file, but it can be opened using any other version as well. This module returns the stress matrix of a 4-node stress hybrid quadrilateral. Argument na is the number of independent stress parameters.
Argument scoor holds the stress point coordinates.
These may be variable or numeric. For convenience in the evaluation of the boundary integral to get G, it is computed only for a specific side identified by index 1,2,3,4 for 12,23,34,41, respectively. Argument sxi is the isoparametric side coordinate, which may be symbolic or numeric.