Back in the "Good Old Days" the DC8 50 series (and maybe other DC8s) had a thin Al strip attached to the lower edge of the MLG oleos, pointing up. Part of the T/R check for the LAME (me) was to check the strip was not bent. Strip bent = hard landing, inspection required - strip not bent landing OK, well structurally at least.
I am at a complete loss as to why modern types do not use such a simply system to help monitor hard landing. BTW we nicknamed the strips "lie detectors".
