Basic definition：

● Acceleration of gravity

the accelerated velocity in the surface of earth caused by gravity.

● Pulse duration：

Shock pulse rises from the reference value to the maximun value, the time it taks to decrease to the reference value.

● Severity of shock test

It's the combination of peak acceleration and nominal pulse duration.

● Velocity variation

The absolute value of sudden velocity variation caused by the implementation of specified acceleration.

● Basic pulse waveform

a. Half-sine pulse: Ideal pulse with the time course curve which is half period of half-sine wave.

b. Postpeak sawtooth pulse: Ideal shock pulse with the time course curve which has asymmetric triangle with short falling time.

c. Trapezoidal pulse: Time course curve is the symmetric quadrangle with short rising and falling time.