The topic of the presentation covers the area of the experimental vibration analysis. Also numerical simulation in SolidWorks can be used as an accessment tool.

1. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Student: Richard Fankhänel
Group/Institution: Dresden University of Technology (Germany)
Superviser: Dr.-Ing. mult. Mikhail A. Petrov
Department «Material forming and additive technologies»
Investigation of the vibrations propagated in the
mechanical press with C-frame applied for cold
working of metal sheets
Moscow, 05/10/2016

2. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Structure of the presentation
1. Dresden and TU Dresden
2. Motivation
3. The task of the internship
4. Theoretical background of vibrations
5. The eccentric press
6. Our results
7. Conclusions
8. Literature/references
2/42

3. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
1. Dresden and TU Dresden
flag
coat of arms 3/42

4. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
1. Dresden and TU Dresden
4/42
Terrassen view on downtown (Altstadt)

5. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
1. Dresden and TU Dresden
Semperoper
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6. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
1. Dresden and TU Dresden
The city was fully destroyed during the 2nd World War (1945).
6/42

7. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Church of Our Lady (Frauenkirche)
1945 nowadays
1. Dresden and TU Dresden
7/42

8. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
1. Dresden and TU Dresden
Georg-Schumann-BuildingBeyer-Building
Lecture-hall
8/42

9. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
• Founded in 1828
• 36.800 students
• 7.800 employees
• 124 study facilities
• One of the 11 elite universities in Germany
• Place 164th in Times University Ranking (state on 2016)
1. Dresden and TU Dresden
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10. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
2. Motivation
Even small vibrations can damage expensive products (e.g. solar panels)
during its production.
10/42

11. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
2. Motivation
Examples of press foundations with installed isolation units
against vibrations for large presses.
11/42

12. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
3.The main task of the internship
• Major subject of interest:
“Development of a bed for a press above 630 MN
with sufficient stiffness and increased vibration
resistance where damping of vibrations occur only
due to proper material and bed structure”
12/42

13. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
eccentric press with nominal force of 0,63 MN its 3D-model
13/42
3.The main task of the internship

14. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
4.Theoretical background of vibrations
14/42

15. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
• Natural frequency
4.Theoretical background of vibrations
15/42

16. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
• Fourier transformation:
1. System is exited to oscillate
2. Measurements of the
system response
3. Using Fourier
transformation to separate
and identify the associated
natural frequencies
4.Theoretical background of vibrations
16/42

17. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
4.Theoretical background of vibrations
The vibration curve can be represented as a sum of the curves, captured
for different frequencies at a certain period of time (Fourier transformation).
17/42

18. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Measuring of the vibrations
• Piezoelectric sensor
- piezo-effect was discovered by Pierre Curie in 1880;
- a sensor converts applied stress into an electrical current (signal).
18/42

19. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Size and weight of the press:
• Height: 2.650 mm
• Width: 750 mm
• Depth: 1.470 mm
• Weight: 5.300 kg
5. The eccentric press
19/42

20. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
5. The eccentric press
connecting rod
eccentric (main) shaft
press table
spur gear
ram
primary
drive shaft
flywheel
20/42

21. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
21/42
shafts are coupled through
spur gear
shafts are coupled through
friction point
5. The eccentric press

22. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Using SW Simulation tool
22/42
general view

23. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Using SW Simulation tool
23/42
constraints of the C-frame

24. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Using SW Simulation tool
24/42
torque moment for the flywheel

25. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Using SW Simulation tool
25/42
triangulation with the tetrahedral elements for FEA

26. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Using SW Simulation tool
26/42
post-processing, showing the calculation results

27. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Using SW Simulation tool
27/42
table with
results,
obtained in the
frequency
analysis study

28. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
28/42
- object for vibration measurements:
eccentric press with nominal force of 0,4 MN
- art of loading: punching operation
Acceleration measurements on the real machine

29. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Acceleration measurements
during machine working.
Sensor placement: press table,
side surface of the frame.
29/42
Two investigated cases:
- no ram/punch movement
- ram/punch movement
axes/planes orientation:
Acceleration measurements on the real machine
XOY – vertical plane
XOZ – horizontal plane
YOZ – front plane

30. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
A vibrating tuning fork makes a typical
sinus movement with known natural
frequencies (440 Hz for the A-note).
Provide a reference value!
measuring of the acceleration
connecting with frequencies
Experiment: tuning fork
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31. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
tuning folk, for
A-note
(440 Hz)
pad with the
software for
acoustic
measurements
tuning device with the
A-note of 440Hz
(tuning range: 0A(27,5)
– 8C(4186,01Hz))
vibration
sensor
31/42
Experiment: tuning fork

32. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
6. Results
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I. Acceleration measurements:
1) obtained from the simulation in SW;
2) obtained from the reference measurements (tuning folk);
3) obtained from the real measurements during press idle run and
working run.
II. Data verification

33. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Experiment: tuning fork
33/42

34. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
• Punch Movement
Experiment: eccentric press
34/42

35. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
• No punch movement
35/42
Experiment: eccentric press

36. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
press is switched OFF,
environmental level of
vibrations
press is switched ON,
idle run
press is switched ON,
work running,
punching
acceleration changes are shown only for Z-direction (in dB)
36/42
Experiment: eccentric press

37. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Computing with Matlab
37/42describing the measured values by the spline-function

38. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Upscaling of the press
38/42
non-linear dependencies of
the geometric sizes of the
press equipment depends
on the nominal forces
F – force scale factor = F2/F1
G – geometry scale factor = H1/H2
G = F
-0,5

39. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Upscaling the press
F1 = 0,63 MN
F2 = 200 MN
H1 = 2.500 mm
H2 = 44.720 mm
39/42
H = press height, mm
F = nominal force, MN

40. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
7. Conclusions and outlooks
40/42
1) Vibrations can be simulated in SolidWorks Simulation package in two studies:
frequency analysis and linear dynamic.
2) The numerically obtained natural frequencies for the press should be filtered,
whereby the acceleration measurements have to be differentiated on
frequencies.
3) After capturing the reference values of the accelerations (tuning folk method),
the measuring principle of the measurement device (vibrometer) was realized.
4) Maximum acceleration values were obtained in the direction of ram/punch
displacement (Y-axis) and the direction of material feeding (Z-axis), which lay in
the vertical plane. This fact means the strong dependency of the accelerations
from the inertial forces of the rotated flywheel.
5) Measured acceleration values can be approximated through the function as an
art of the spline-function used in Matlab.
6) Upscaled machines does not have the linear dependency of the geometry from
the nominal force. It is expected, that the non-linear dependency will occur also
for the accelerations, measured in three directions.

41. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
8. Literature/references
• M. Geradin, D. J. Rixen, Mechanical vibrations. Theory and application to
structural dynamic, 3rd edition, John Wiley & Sons, 2015.
• P. Petrov, M. Petrov, V. Voronkov, D. Grishin, Numerical investigation of the hot
isothermal process and force size-effect of a clutch-half forming, Key
Engineering Materials, Vol. 611-612, 2014, pp. 1608-1616.
• K. Tanaka, K. Hayakawa, I. Nakaya, Characteristic and propagation of the
environmental ground vibration caused by two kinds of large power press
machines, Proceedings of the 40th International congress and exposition on
noise control engineering, Osaka, Japan, 2011, Vol. 1, pp. 2148 – 2153.
• www.en.wikipedia.org/wiki/Piezoelectric_sensor
• www.helix.gatech.edu/Classes/ME2202/2000S3/Projects/Swarner/definition.html
• www.gerb.com
• www.vibrodynamics.com/english/bulletin/ml711-mrm-technical.pdf
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42. “Investigation of the vibrations propagated in
the mechanical press with C-frame applied for
cold working of metal sheets”
Thank you for attention!