 Emilio Alfaro-Bou

Emilio Alfaro-Bou contributed experimental crashworthiness research at NASA Langley, including the use of measured aircraft crash pulses to test energy-absorbing seat structures. The publisher names him in full as the first author of the 1981 paper whose citation abbreviates the name to E. Alfaro-Bou.^[ref]

The study analyzed acceleration histories from twelve light-aircraft crash tests. It then used two vertical drop tests at $12.8\mathrm{m}{\mathrm{s}}^{-1}$ to assess an energy-absorbing seat prototype under a specified impact pulse, comparing instrumented dummy and structural response with a finite element method model.^[ref] The physical question is how a load path changes the acceleration-time history; a static strength measurement alone does not answer it.

For an original ideal pulse comparison, take a rigid test mass initially moving at $12\mathrm{m}{\mathrm{s}}^{-1}$. A constant opposing acceleration of $200\mathrm{m}{\mathrm{s}}^{-2}$ stops it in $0.060\mathrm{s}$ over $0.36\mathrm{m}$. Halving that acceleration to $100\mathrm{m}{\mathrm{s}}^{-2}$ doubles the time to $0.120\mathrm{s}$ and the stopping distance to $0.72\mathrm{m}$:Both pulses remove the same momentum per unit mass, $\int adt=12\mathrm{m}{\mathrm{s}}^{-1}$, but require different deformation strokes. These stipulated constant pulses illustrate the tradeoff; they are not measured histories from the paper.