  This paper presents experimental evidence of the existence of acoustic valley
Hall (AVHE) edge states in topological elastic waveguides. The fundamental
lattice is assembled based on a non-resonant unit where space inversion
symmetry (SIS) is broken by simply perturbing the underlying lattice geometry.
This aspect is in net contrast with existing elastic AVHE designs that exploit
locally-resonant units and require the addition of masses in order to break
SIS. The experimental results presented in this study validate findings so far
presented only at theoretical and numerical level. In particular, it is found
that edge modes can effectively propagate along domain walls between
topologically dissimilar domains and that disorder-induced backscattering is
substantially suppressed due to the weak coupling between oppositely
valley-polarized modes. The coupling between valley modes is also further
investigated and linked to an evident chiral flux of the mechanical energy.
Finally, we show that the weak coupling between the valleys can be exploited to
achieve selective mode injection at the domain wall, hence realizing a very
effective excitation strategy of the chiral edge states.
