Half-sine waveform generator, commonly known as PU pad, is made of polyurethane material and it can be divided into three types: yellow half-sine wave generator, red half-sine wave generator and green half-sine wave generator. The color is used to indicate the intensity and stiffness, so different colors of the generator have different elastic rates which control impulse duration. Yellow wave pad is the hardest which is suitable for large acceleration and small pulse width waveform, green wave pad is the softest which is suitable for small acceleration and large pulse width and the performance of red wave pad is between the two.
Compared with half-sine pulse and trapezoidal pulse, postpeak sawtooth pulse is a kind of uniform response spectrum and its waveform generator is usually lead.
The trapezoidal pulse can produce a higher response than the half-sine pulse on a wide spectrum. Trapezoidal waveform is suitable for the testings designed to simulate the effect of the shock environment caused by the explosive bolt in the space probe or the satellite launching stage.