Mechanical shock is distinguished from impact in that all the parameters of the event (pulse shape, peak acceleration, duration, etc.) are controlled. An impact, on the other hand, is characterized as an uncontrolled mechanical meeting of two surfaces.
The purpose of shock testing is to determine the sensitivity of a product to impact. This is normally referred to as product fragility analysis.
Impacts of a harmful nature are very common during product transportation and distribution. In fact, transportation represents the most severe mechanical environment of most products entire lifecycle. Some products are also subjected to high levels of impact in the in-use environment based on their function. Handheld calculators, children’s toys, cellular telephones, and much military equipment are examples.
The reliability of most electromechanical products can be greatly enhanced by a carefully applied series of mechanical shock tests designed to identify the weakest elements of a product and fixing those weaknesses by judicious use of recognized design principles.
MIL STD 810 G
Mechanical shock tests are carefully designed to control parameters such as pulse shape, peak acceleration and duration.
(8) Programmable Shock Machines