"Jim Wilkins" writes:

http://physics.wm.edu/~labs/110/110_pdf/ch4.pdf
If the metal permanently deforms some of the kinetic energy converts
to heat.

Resilient design - make sure that in an extreme event, there's
not-a-lot / no abrupt breaking (low energy and structure is lost) and
a lot of distributed bending and deformation (high energy, and the
structure is still there)... :-)

Job as a welder - repair a height-restriction barrier at a supermarket
http://www.weldsmith.co.uk/dropbox/m...tS_htbarr.html
"Insert plates" so knocking it over again would be a long energy
consuming process.