The figure shows two different transients with more realistic exponential acceleration laws, in which again the maximum amplitude is more than halved when a high acceleration is applied. Also the characteristic fluctuations of the deflection amplitude which arise as soon as the maximum deflection has been passed, a kind of beating phenomenon, is clearly recognizable. So we can go fastly trough a critical speed in order to avoid high vibration levels. This is true only for small machines in which the run up transient can be kept very short with a high acceleration and it is not true for real big machines in which the run up transient and the run down transient are very long.

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