The value
=
k
t
defines the time interval where the average velocity of the
instrument left shank end is calculated (more precisely the displacement of the shank
end over a period of time
=
k
t
).
Figure 9. The fluctuation of the average velocity (a) and the displacement of the
left shank end (b) at
; 1) – the Fourier method, 2) – the difference method
The real device limits the negative displacement of the left shank end. A possible
modeling method of this limitation is the change of characteristic of the working
medium resistance at
0
U
, for example, the value
N
/m.
The oscillations in limiting negative movements are shown in Fig.10. The
oscillation amplitude falls to a certain level with a damping decrement on the average
4
,
1
/
2
1
=
A
A
, which is determined by the value of the technological stiffness с
0
(Fig.
5).
Figure 10. The oscillation suppression of the left shank end under conditions:
P=305 Ns,
20
=
t
,
N/m
We consider the magnitude of error question as a result of a simplified transition
to the lower part of the power characteristic (7) as the sign of the shank end velocity
changes. The power characteristic will be determined depending on the coordinate x
2
.
30
=
t
7
0
10
5
=
c
7
0
10
5
=
c
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