A method for making a ductile and porous shape memory alloy (SMA) using
spark plasma sintering, and an energy absorbing structure including a
ductile and porous SMA are disclosed. In an exemplary structure, an SMA
spring encompasses a generally cylindrical energy absorbing material. The
function of the SMA spring is to resist the bulging of the cylinder under
large compressive loading, thereby increasing a buckling load that the
cylindrical energy absorbing material can accommodate. The SMA spring
also contributes to the resistance of the energy absorbing structure to
an initial compressive loading. Preferably, the cylinder is formed of
ductile, porous and super elastic SMA. A working prototype includes a
NiTi spring, and a porous NiTi cylinder or rod.