ABSTRACT
A fast-moving object, capable of impacting structures on its way, is sometimes referred to as a kinetic energy threat. Such an object can be a round of ammunition, purposely shot to inict damage, but it can also result from an accidental event; e.g., a roong sheet hurled by strong wind. At least some of the effects of those objects on structural elements belong to terminal ballistics, a branch of military engineering. While the terms like penetration and perforation are qualitatively understood by the readers, the exact denition of the latter depends on the area of application.
