Vibration Analysis of a Boring Bar

Document type: Researchreports
Full text:
Author(s): Linus Pettersson
Title: Vibration Analysis of a Boring Bar
Series: Research Report
Year: 2002
Issue: 1
ISSN: 1103-1581
Organization: Blekinge Institute of Technology
Department: Department of Telecommunications and Signal Processing (Institutionen för telekommunikation och signalbehandling)
Department of Telecommunications and Signal Processing S-372 25 Ronneby
+46 455 38 50 00
Authors e-mail: linus.pettersson@bth.se
Language: English
Abstract: In boring operations the vibrations are a cumbersome part of the
manufacturing process. This report puts the vibrations under
scrutiny and the vibrations were measured both in the cutting
speed direction and the cutting depth direction. The cutting
process seems to be a time varying process and
contains nonstationary as well as nonlinear parameters that are not
under control. The experiments showed that the
vibrations were usually dominated by the first resonance frequency
in either of the two directions of the boring bar.
Sample probability density estimates of the
vibration records points to that the probability densities are varying
from sinusiodal probability shape to gaussian shape. They
also indicate that shape of the two directions could be of
different probability density function from the same vibration record.
Stationarity tests show, besides that the processes usually are
nonstationary, that it is possible to extract short time
stationary segments within a vibration record. The problem with
force modulation in rotary machinery, which appears as side band
terms is the spectrum, is also addressed. Furthermore, the
resonance frequencies of the boring bar are correlated to an
approximate theoretical beam model. The theoretical calculation
of the boring bar deflection corresponds well with the
experimental results from the modal analysis and the
operating deflection shape analysis.
Subject: Signal Processing\Active Noise and Vibration Control
Signal Processing\General
Keywords: Lathe, Vibration, Boring, Turning
URN: urn:nbn:se:bth-00201
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