The influence of tool geometry on damping during machining: A theoretical and fundamental study
(2022) MMTM05 20221Production and Materials Engineering
- Abstract
- The growing importance of achieving high productivity in the manufacturing industry leads to the necessity for applying high machining parameters and cutting speeds. However, the presence of self-excited vibrations of the tool shaft and workpiece under these conditions would result in undesirable surface roughness and surface integrity of the product. Thus, it is vital to study the damping mechanisms in metal cutting processes and the influencing factors so as to attenuate the oscillation amplitudes.
The present study aims to investigate tool flank interaction with the workpiece as one of the damping mechanisms in machining. Three different approaches have been employed to measure the damping in low cutting velocities:
1. Signal... (More) - The growing importance of achieving high productivity in the manufacturing industry leads to the necessity for applying high machining parameters and cutting speeds. However, the presence of self-excited vibrations of the tool shaft and workpiece under these conditions would result in undesirable surface roughness and surface integrity of the product. Thus, it is vital to study the damping mechanisms in metal cutting processes and the influencing factors so as to attenuate the oscillation amplitudes.
The present study aims to investigate tool flank interaction with the workpiece as one of the damping mechanisms in machining. Three different approaches have been employed to measure the damping in low cutting velocities:
1. Signal Processing
2. Surface topography
3. Chip segmentation analysis
It has been shown that the damping coefficient in the feed direction would increase by increasing the amount of synthetic tool wear while low cutting speeds (< 100 m/min) while at higher speeds, no increasing trend can be found as the temperature rise on flexural strength of chips would be noticeable and the energy loss in force transferring through chips would be non-linearly increase. The results obtained from signal processing have been compared to ones achieved from surface topography measurements and chip segmentation analysis so as to examine their reliability.
Last but not least, the conventional theories of chip formation have been studied as they were over-simplified considering only geometrical relationships and not the effect of velocity and corresponding shear strain rate and temperature rise in chip formation.
By and large, the study investigates the framework introduced by JE Ståhl for studying chatter in metal cutting processes. (Less) - Popular Abstract
- Self-induced vibration in metal cutting processes is a phenomenon bringing about higher roughness of the generated surface. However, the mechanism of chip formation and insert/workpiece interaction would result in damping effects which attenuates the oscillation of the vibrations. In the past 70 years, it has been focusing on explaining what is happening during a process that causes damping and trying to derive mathematical models for the tool holder vibrations. The study aims to investigate conventional mathematical models in chip formation theories and vibrations of the tool holder.
By utilizing signal processing methods and surface topography measurements, this project highlighted the complexity of vibrations of the tool holder and... (More) - Self-induced vibration in metal cutting processes is a phenomenon bringing about higher roughness of the generated surface. However, the mechanism of chip formation and insert/workpiece interaction would result in damping effects which attenuates the oscillation of the vibrations. In the past 70 years, it has been focusing on explaining what is happening during a process that causes damping and trying to derive mathematical models for the tool holder vibrations. The study aims to investigate conventional mathematical models in chip formation theories and vibrations of the tool holder.
By utilizing signal processing methods and surface topography measurements, this project highlighted the complexity of vibrations of the tool holder and the extent to which the conventional models are valid. Moreover, the effect of flank wear and cutting velocity has been examined on process damping by conducting face turning of a gery cast-iron brake disc. Moreover, the impact of cutting velocity on the shear strain and the parameter chip compression ratio has been answered.
With the increasing need for a high production rate and corresponding cutting velocity along with lower desired tolerances and better surface integrity and predictive tool wear, this study has verified the previous framework developed by Jan-Eric Ståhl to investigate the effect of tool wear and cutting velocity on the vibrations of the tool holder during critical and sub-critical machining. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9087381
- author
- Rostami, Parsa LU
- supervisor
- organization
- course
- MMTM05 20221
- year
- 2022
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Self-induced vibrations, damping, metal cutting
- report number
- LUTMDN/(TMMV-5340)/1-69/2022
- language
- English
- id
- 9087381
- date added to LUP
- 2022-06-13 08:41:23
- date last changed
- 2022-06-13 08:41:23
@misc{9087381,
abstract = {{The growing importance of achieving high productivity in the manufacturing industry leads to the necessity for applying high machining parameters and cutting speeds. However, the presence of self-excited vibrations of the tool shaft and workpiece under these conditions would result in undesirable surface roughness and surface integrity of the product. Thus, it is vital to study the damping mechanisms in metal cutting processes and the influencing factors so as to attenuate the oscillation amplitudes.
The present study aims to investigate tool flank interaction with the workpiece as one of the damping mechanisms in machining. Three different approaches have been employed to measure the damping in low cutting velocities:
1. Signal Processing
2. Surface topography
3. Chip segmentation analysis
It has been shown that the damping coefficient in the feed direction would increase by increasing the amount of synthetic tool wear while low cutting speeds (< 100 m/min) while at higher speeds, no increasing trend can be found as the temperature rise on flexural strength of chips would be noticeable and the energy loss in force transferring through chips would be non-linearly increase. The results obtained from signal processing have been compared to ones achieved from surface topography measurements and chip segmentation analysis so as to examine their reliability.
Last but not least, the conventional theories of chip formation have been studied as they were over-simplified considering only geometrical relationships and not the effect of velocity and corresponding shear strain rate and temperature rise in chip formation.
By and large, the study investigates the framework introduced by JE Ståhl for studying chatter in metal cutting processes.}},
author = {{Rostami, Parsa}},
language = {{eng}},
note = {{Student Paper}},
title = {{The influence of tool geometry on damping during machining: A theoretical and fundamental study}},
year = {{2022}},
}