Besides, the amplitude and the phase of vibration are less influenced by the fluctuation of the actuation frequency.
Besides, the large amplitude and the phase of vibration are maintained when the actuation frequency fluctuates.
It is necessary to take into account, that statistically proved data on surface of contact differs within certain tolerance and phase of vibration
from touching roughness profile is also unknown.
The impact of weld pressure and vibration amplitude and frequency on these variables, therefore, needs to be investigated using mathematical models for each phase of vibration welding.
The final phase of vibration welding, phase IV, in which the vibratory motion is stopped and the melt-film cools under pressure, is the most difficult to study experimentally because of its short and transient nature.
In this case, integral limits at the hologram exposure will be from [delta][T.sub.2] - [[tau].sub.i]/2 up to [delta][T.sub.2] + [[tau].sub.i]/2 and taking into account that the midpoint of strobo pulse in case of the component [A.sub.2]sin([[omega].sub.2]t+[theta]) will correspond the random phase of vibration
[[omega].sub.2][delta][T.sub.2] and assuming the strobo pulse duration equivalent to the hologram exposure duration during a single period [[tau].sub.i] = [T.sub.e] the following expression is obtained: