  We investigate and experimentally demonstrate the elastic wave filtering
properties of graded undulated lattices. Square reticulates composed of curved
beams are characterized by graded mechanical properties which result from the
spatial modulation of the curvature parameter. Among such properties, the
progressive formation of frequency bandgaps leads to strong wave attenuation
over a broad frequency range. The experimental investigation of wave
transmission, and the detection of full wavefields effectively illustrate this
behavior. Transmission measurements are conducted using a scanning Laser
vibrometer, while a dedicated digital image correlation procedure is
implemented to capture in-plane wave motion at selected frequencies. The
presented results illustrate the broadband attenuation characteristics
resulting from spatial grading of the lattice curvature, whose in-depth
investigation is enabled by the presented experimental procedures.
