which are more complex than flexural or out-of-plane waves because of the coupling of P-
and SV-waves. First, refracted generalized Snell's law (GSL) for a mixed in-plane wave is
deduced, which is also testified by the numerical results. Then, according to the GSL, elastic
metasurfaces are designed to realize multifunctions such as directional refraction and wave
focusing for different working frequencies. Critical refraction is discussed for the directional …