“shock” refers to a physical action in which a high-magnitude external force pulse is applied to a product in an extremely short time (instantaneously), including mechanical shocks such as free fall, flipping, throwing, slapping, and collision during transportation and use, as well as various environmental phenomena such as ballistic shock and explosion shock. The duration of the impact is called “pulse width” or “pulse period”, and the unit is milliseconds (ms). The degree of the magnitude of the external force applied is measured by “peak acceleration”, and the unit is (m/s’). The industry often uses gravity acceleration (g) to represent it.
Since the duration of the shock is very short, such as the duration of mechanical shock does not exceed 1.0s, usually in the range of a few milliseconds to tens of milliseconds, the duration of ballistic shock and explosion shock is even shorter. However, the force generated by the impact is very large, and the peak acceleration of the impact is very high. For example, the peak acceleration of general mechanical shock is tens of g to hundreds of g, and the peak acceleration of ballistic shock and explosion shock may be as high as tens of thousands to hundreds of thousands of g.
The time domain function of the impact is a pulse function with a very high amplitude and extremely fast decay. The upper frequency limit of the spectrum of most mechanical impact sources in environmental tests does not exceed (2~5)x103Hz. The time domain response characteristics of a general product subjected to impact can be enveloped by an exponential function that decreases with time, and the upper frequency limit of its impact response spectrum usually does not exceed 105 Hz.