  Zero-temperature field-induced polarization, supercurrent density, and the
related electrostriction (ES) of a granular superconductor are calculated
within a model of 3D Josephson junction arrays. Both the "bulk-modulus-driven
ES" (the change of the sample's volume in the free energy upon the applied
stress) and the "change-of-phase ES" (due to the stress dependence of the
weak-links-induced polarization) are considered. In contrast to
magnetostriction of a granular superconductor, its electroelastic behavior is
predicted to be dominated by the former contribution for all applied fields.
