The elastic strain energies of circular inclusions with a sliding and bonde
d interfaces are compared. It is shown that the energy in the inclusion wit
h sliding interface due to uniform eigenstrain is greater than the energy i
n the inclusion with a bonded interface if the Poisson ratio of the materia
l is less than 1/6, and smaller if it is greater than 1/6. The total energy
in the inclusion and the matrix due to uniform eigenstrain is always small
er in the case of a sliding inclusion. The opposite is true for the inclusi
on under remote uniform loading at infinity. The relationships between the
energies of sliding and bonded inhomogeneities are also derived.