Indication of cracking during pressing of advanced thin plates using an AE-based monitoring system
(2010) Tools and Technologies for the processing of ultra high strength steels: IDDRG 2010 International Conference p.925-934- Abstract
- The acoustic emission that is detectable in the forming of complex thin part
plates contains information about the quality of the pressed plates. The information can
be used as process control and to filter out advanced thin plates with defects such as
cracks.
The article describes the results obtained in a try-out pressing process in special
developed punch-die pairs with different pressing depths in a press at Alfa Laval in
Lund. At the trials two module testing tools called SE30 and SE25 were used to create a
different degree of formability by different surface enlargement in the same complex
original design. Used sheet materials were stainless steel and two... (More) - The acoustic emission that is detectable in the forming of complex thin part
plates contains information about the quality of the pressed plates. The information can
be used as process control and to filter out advanced thin plates with defects such as
cracks.
The article describes the results obtained in a try-out pressing process in special
developed punch-die pairs with different pressing depths in a press at Alfa Laval in
Lund. At the trials two module testing tools called SE30 and SE25 were used to create a
different degree of formability by different surface enlargement in the same complex
original design. Used sheet materials were stainless steel and two qualities of titanium.
The used measuring system was based on a PC with AE-sensor of model 8152 from
Kistler.
The results of experiments show that it is possible to detect and distinguish the
plates that fracture during the forming operation. For a large number of plates detectable
signals from areas close to cracks with only local necking were also obtained. This local
necking cannot or can hardly be detected by light-test or light detecting equipment.
The left figure shows a metal sheet
with fractures and the right figure
describes measured acoustic
emission as a function of time and
the number of the details. In this
example the first four plates are
fractured and the last five plates are
without any fractures. There are several differences between the two types of signals of
acoustic emission. The signal that indicates cracking of the plate differs by a sudden
high acoustic emission and also a slightly lower level before the crack formation is
started. Before the fracture occurs the sheet metal is stretched out and the lower level of
acoustic emission also indicates less movement of the sheet metal just before the time of
fracture. The purpose of the conducted experiment was to find out whether the selected approach
was appropriate. The obtained result shows unambiguously that the chosen approach is
pertinent and that an AE-based monitoring system can be used as a process control
system to ensure the quality of production of advanced thin plates in stainless steel and
titanium. Information can be saved from the main forming operation and can be used to
see trends both long and short term. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4378551
- author
- Gabrielson, Per LU ; Skåre, Thomas LU and Ståhl, Jan-Eric LU
- organization
- publishing date
- 2010
- type
- Chapter in Book/Report/Conference proceeding
- publication status
- published
- subject
- keywords
- complex, process control, acoustic emission, stainless steel, forming, titanium
- host publication
- Tools and Technologies for the Processing of Ultra High Strength Steels: IDDRG Conference Proceedings ; 50th Anniversary Conference, 2010 May 31 - Juni 02, Graz, Austria
- editor
- Kolleck, Rolf
- pages
- 925 - 934
- publisher
- Verlag der Technischen Univiversität Graz
- conference name
- Tools and Technologies for the processing of ultra high strength steels: IDDRG 2010 International Conference
- conference location
- Graz, Austria
- conference dates
- 2010-05-31 - 2010-06-02
- ISBN
- 9783851251081
- language
- English
- LU publication?
- yes
- additional info
- IDDRG International Conference IDDRG Conference International Deep Drawing Research Group Anniversary Conference IDDRG 50th Anniversary Conference
- id
- e46e2f41-a794-4326-be2a-4cab48f71388 (old id 4378551)
- date added to LUP
- 2016-04-04 10:42:22
- date last changed
- 2018-11-21 21:00:19
@inproceedings{e46e2f41-a794-4326-be2a-4cab48f71388, abstract = {{The acoustic emission that is detectable in the forming of complex thin part <br/><br> plates contains information about the quality of the pressed plates. The information can <br/><br> be used as process control and to filter out advanced thin plates with defects such as <br/><br> cracks. <br/><br> The article describes the results obtained in a try-out pressing process in special <br/><br> developed punch-die pairs with different pressing depths in a press at Alfa Laval in <br/><br> Lund. At the trials two module testing tools called SE30 and SE25 were used to create a <br/><br> different degree of formability by different surface enlargement in the same complex <br/><br> original design. Used sheet materials were stainless steel and two qualities of titanium. <br/><br> The used measuring system was based on a PC with AE-sensor of model 8152 from <br/><br> Kistler. <br/><br> The results of experiments show that it is possible to detect and distinguish the <br/><br> plates that fracture during the forming operation. For a large number of plates detectable <br/><br> signals from areas close to cracks with only local necking were also obtained. This local <br/><br> necking cannot or can hardly be detected by light-test or light detecting equipment. <br/><br> The left figure shows a metal sheet <br/><br> with fractures and the right figure <br/><br> describes measured acoustic <br/><br> emission as a function of time and <br/><br> the number of the details. In this <br/><br> example the first four plates are <br/><br> fractured and the last five plates are <br/><br> without any fractures. There are several differences between the two types of signals of <br/><br> acoustic emission. The signal that indicates cracking of the plate differs by a sudden <br/><br> high acoustic emission and also a slightly lower level before the crack formation is <br/><br> started. Before the fracture occurs the sheet metal is stretched out and the lower level of <br/><br> acoustic emission also indicates less movement of the sheet metal just before the time of <br/><br> fracture. The purpose of the conducted experiment was to find out whether the selected approach <br/><br> was appropriate. The obtained result shows unambiguously that the chosen approach is <br/><br> pertinent and that an AE-based monitoring system can be used as a process control <br/><br> system to ensure the quality of production of advanced thin plates in stainless steel and <br/><br> titanium. Information can be saved from the main forming operation and can be used to <br/><br> see trends both long and short term.}}, author = {{Gabrielson, Per and Skåre, Thomas and Ståhl, Jan-Eric}}, booktitle = {{Tools and Technologies for the Processing of Ultra High Strength Steels: IDDRG Conference Proceedings ; 50th Anniversary Conference, 2010 May 31 - Juni 02, Graz, Austria}}, editor = {{Kolleck, Rolf}}, isbn = {{9783851251081}}, keywords = {{complex; process control; acoustic emission; stainless steel; forming; titanium}}, language = {{eng}}, pages = {{925--934}}, publisher = {{Verlag der Technischen Univiversität Graz}}, title = {{Indication of cracking during pressing of advanced thin plates using an AE-based monitoring system}}, year = {{2010}}, }