  A new class of strongly nonlinear metamaterials based on tensegrity concepts
is proposed and the solitary wave dynamics under impact loading is
investigated. Such systems can be tuned into elastic hardening or elastic
softening regimes by adjusting local and global prestress. In the softening
regime these metamaterials are able to transform initially compression pulse
into a solitary rarefaction wave followed by oscillatory tail with
progressively decreasing amplitude. Interaction of a compression solitary pulse
with an interface between elastically hardening and softening materials having
correspondingly low-high acoustic impedances demonstrates anomalous behavior: a
train of reflected compression solitary waves in the low impedance material;
and a transmitted solitary rarefaction wave with oscillatory tail in high
impedance material. The interaction of a rarefaction solitary wave with an
interface between elastically softening and elastically hardening materials
with high-low impedances also demonstrates anomalous behavior: a reflected
solitary rarefaction wave with oscillatory tail in the high impedance branch;
and a delayed train of transmitted compression solitary pulses in the low
impedance branch. These anomalous impact transformation properties may allow
for the design of ultimate impact mitigation devices without relying on energy
dissipation.
