Impact & Drop

The mistake this exists to prevent: treating a dropped or suddenly released load as a static one. Even from zero height, a suddenly applied load produces exactly twice the static stress — and a real drop is far worse. Counter-intuitively, a stiffer target makes impact worse, not better, because it has nowhere to put the energy.

The average stopping force assumes the force is constant over the stopping distance; a real peak is typically 1.5–2× higher, so treat it as a lower bound. The dynamic amplification factor assumes a linear elastic target with no damping and no plastic deformation — anything that yields or crushes absorbs energy and reduces the peak substantially, which is exactly what a crush zone is for. Restitution is a property of the pair of materials, not either one alone.