Figure 6: The fundamental solution in two dimensions
with unit force along direction 1
The fundamental solution corresponds to the stress and strain situation generated from placing a unit load at point P along the 1 or 2 direction, as shown in Figure 6. The following two matrices are defined:
are the deformations,
and 
are the tractions, in the case a unit load along the direction 1 is placed
at any point P inside or on the surface of the 2-D body. The rest
of the elements of the two matrices correspond to a unit load along
the direction 2. The elements of the two matrices are given from:
and
where 
is the shear modulus ( 
);
and 
are the projections of 
and the normal
unit vector 
along 
and 
, respectively.
