= Emilio Alfaro-Bou
{c}
= E. Alfaro-Bou
{c}
{synonym}
<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.<Determination of crash test pulses and their application to aircraft seat analysis by E. Alfaro-Bou and others>[Publisher author list and citation, DOI10.4271/810611]{ref}
The study analyzed acceleration histories from twelve light-aircraft crash tests. It then used two vertical drop tests at $12.8\,\mathrm{m\,s^{-1}}$ to assess an energy-absorbing seat prototype under a specified impact pulse, comparing instrumented dummy and structural response with a <finite element method> model.<Determination of crash test pulses and their application to aircraft seat analysis by E. Alfaro-Bou and others>[Author abstract, NASA NTRS19810058363 and publisher abstract]{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 $12\,\mathrm{m\,s^{-1}}$. A constant opposing acceleration of $200\,\mathrm{m\,s^{-2}}$ stops it in $0.060\,\mathrm{s}$ over $0.36\,\mathrm m$. Halving that acceleration to $100\,\mathrm{m\,s^{-2}}$ doubles the time to $0.120\,\mathrm{s}$ and the stopping distance to $0.72\,\mathrm m$:
$$
t=\frac va,\qquad s=\frac{v^2}{2a}.
$$
Both pulses remove the same momentum per unit mass, $\int a\,dt=12\,\mathrm{m\,s^{-1}}$, but require different deformation strokes. These stipulated constant pulses illustrate the tradeoff; they are not measured histories from the paper.
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