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The first chapter is dedicated to analysis of the previous works related on a study
of vibrations excited by friction is carried out. It is emphasized that in the literature
two main mechanisms for generating vibration signals, which depend on the contact
conditions are distinguished namely a low level of adhesive interaction (normal
friction) and a high level with elements of local adhesion between surfaces (intense
destruction of surfaces). If the interaction between the surfaces takes place under
normal friction, then the acoustic waves are exciting by the collision of rigid
irregularities and propagate in each of contacting surfaces, generating their own
oscillations that are practically independent of each other. In the case of a high level
of adhesive interaction, frictional forces can change the dynamics of the entire
system, and then the system's response becomes nonlinear. Frictional interaction
finally depends on the specifics of the mechanical system, boundary conditions, and
properties of contact surfaces, normal contact load, environment and a number of
other factors. Each of them, in addition to changing the tribological characteristics
(friction coefficient, wear, temperature), affect the systemʼs response, changing the
overall power and spectral composition of vibration signals. Many researchers chose
a simple friction system with one degree of freedom for the analytical and numerical
analysis of vibrations, excited by friction. The friction force in this case is a non-
linear function of the sliding velocity, represented by a power series. Then nonlinear
terms and the damping component can be combined together and the friction-velocity
characteristics can be considered together as the some form of damping. Due to the
nonlinearity of the friction-velocity characteristic and the influence of external
disturbance, stable solutions of the second-order nonlinear differential equation must
be found in different modes of friction. Procedures for obtaining solutions even in the
first approximation are quite cumbersome.
Basing on the results presented in the literature, it can be concluded that a
number of regularities related to the frictional excitation of vibrations were
established and verified experimentally on the basis of this simplest model of the
friction system. However, because of the multi factorial influence on this
phenomenon, many problems remained outside the attention of researchers. One of
The first chapter is dedicated to analysis of the previous works related on a study
of vibrations excited by friction is carried out. It is emphasized that in the literature
two main mechanisms for generating vibration signals, which depend on the contact
conditions are distinguished namely a low level of adhesive interaction (normal
friction) and a high level with elements of local adhesion between surfaces (intense
destruction of surfaces). If the interaction between the surfaces takes place under
normal friction, then the acoustic waves are exciting by the collision of rigid
irregularities and propagate in each of contacting surfaces, generating their own
oscillations that are practically independent of each other. In the case of a high level
of adhesive interaction, frictional forces can change the dynamics of the entire
system, and then the system's response becomes nonlinear. Frictional interaction
finally depends on the specifics of the mechanical system, boundary conditions, and
properties of contact surfaces, normal contact load, environment and a number of
other factors. Each of them, in addition to changing the tribological characteristics
(friction coefficient, wear, temperature), affect the systemʼs response, changing the
overall power and spectral composition of vibration signals. Many researchers chose
a simple friction system with one degree of freedom for the analytical and numerical
analysis of vibrations, excited by friction. The friction force in this case is a non-
linear function of the sliding velocity, represented by a power series. Then nonlinear
terms and the damping component can be combined together and the friction-velocity
characteristics can be considered together as the some form of damping. Due to the
nonlinearity of the friction-velocity characteristic and the influence of external
disturbance, stable solutions of the second-order nonlinear differential equation must
be found in different modes of friction. Procedures for obtaining solutions even in the
first approximation are quite cumbersome.
Basing on the results presented in the literature, it can be concluded that a
number of regularities related to the frictional excitation of vibrations were
established and verified experimentally on the basis of this simplest model of the
friction system. However, because of the multi factorial influence on this
phenomenon, many problems remained outside the attention of researchers. One of
