  Giant planets are believed to host central dense rocky/icy cores that are key
actors in the core-accretion scenario for their formation. In the same time,
some of their components are unstable in the temperature and pressure regimes
of central regions of giant planets and only ab-initio EOS computations can
address the question of the state of matter. In this framework, several works
demonstrated that erosion and redistribution of core materials in the envelope
must be taken into account. These complex mechanisms thus may deeply modify
giant planet interiors for which signatures of strong tidal dissipation have
been obtained for Jupiter and Saturn. The best candidates to explain this
dissipation are the viscoelastic dissipation in the central dense core and
turbulent friction acting on tidal inertial waves in their fluid convective
envelope. In this work, we study the consequences of the possible melting of
central regions for the efficiency of each of these mechanisms.
