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@PHDTHESIS{Stebner:995044,
author = {Stebner, Sophie Charlotte},
othercontributors = {Münstermann, Sebastian and Volk, Wolfram},
title = {{D}evelopment of a soft sensor system for the
property-controlled process design of freeform bending with
moveable die},
school = {Rheinisch-Westfälische Technische Hochschule Aachen},
type = {Dissertation},
address = {Aachen},
publisher = {RWTH Aachen University},
reportid = {RWTH-2024-09686},
pages = {1 Online-Ressource : Illustrationen},
year = {2024},
note = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen
University; Dissertation, Rheinisch-Westfälische Technische
Hochschule Aachen, 2024},
abstract = {The freeform bending process with movable die is an
innovative bending process that allows the manufacture of
complex three-dimensional geometries without a change in the
bending tool. Thus, it offers a high degree of design
freedom and customization. The initial situation of this
scientific work was the ability of bending complex
geometries, however without any knowledge on relevant
mechanical properties, that were set in the bent component.
This led to high amounts of scrap material, time consuming
adjustment procedures during the process as well as unknown
reliability regarding the component’s performance. Hence,
there is a need to implement a closed-loop property-control
into the freeform bending process, that can adjust the
degrees of freedom on offer during the bending procedure
according to the needed mechanical properties of the tube.
Mechanical properties that are especially of interest for
bent round tubes are the strength, ductility as well as the
residual stresses in axial and hoop direction, as they
predominantly determine the components application. However,
these mechanical properties are time-consuming or even
impossible to determine during the bending process, where it
is necessary to know them, in order to be able to manipulate
the actuators according to the needed properties. Hence,
there needs to be a fast, reliable and efficient solution
for the derivation of the strength, ductility and residual
stresses in the tubes. Thus, the focus of this work lies on
the conception of a so-called soft sensor based on
state-space models that can quickly derive the relevant
mechanical properties during the bending process. The soft
sensor relies on Ultrasonic Contact Impedance hardness and
Barkhausen Noise measurements that are susceptible to a
change in macroscopical/microscopical properties in the
investigated material and can, furthermore, be implemented
into the bending machine. Strength, ductility, hoop, and
residual axial stress measurements are taken partly
experimentally as well as numerically and are correlated to
the Ultrasonic Contact Impedance hardness and Barkhausen
Noise respectively such that a fast and reliable derivation
of the relevant mechanical properties is enabled. Hence,
this work lies the foundation for a closed-loop
property-control of the bending process in introducing a
methodology for the quick and reliable determination of
immeasurable parameters in a component allowing a more
resource and economically efficient design of the process.},
cin = {522520 ; 522510 / 520000 / 080018},
ddc = {620},
cid = {$I:(DE-82)522520_20140620$ / $I:(DE-82)520000_20140620$ /
$I:(DE-82)080018_20160203$},
pnm = {DFG project G:(GEPRIS)424334318 - Eigenschaftsgeregelte
Prozessgestaltung des Freiformbiegens unter
Berücksichtigung der Halbzeugeigenschaften (424334318) /
SPP 2183: Eigenschaftsgeregelte Umformprozesse (402694744)},
pid = {G:(GEPRIS)424334318 / G:(GEPRIS)402694744},
typ = {PUB:(DE-HGF)11},
doi = {10.18154/RWTH-2024-09686},
url = {https://publications.rwth-aachen.de/record/995044},
}
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