TY - GEN

T1 - Modal excitation of circular rotating structures using an innovative electromagnetic device

AU - Hoffmann, Thomas

AU - Jahn, Martin

AU - Panning-von Scheidt, Lars

AU - Wallaschek, Jörg

N1 - Funding information: The investigations were conducted as part of the joint research programme COOREFlex-turbo in the frame of AG Turbo. The work was supported by the Bundesministerium für Wirtschaft und Technologie (BMWi) as per resolution of the German Federal Parliament under grant number 03ET7041L. The responsibility for the content lies solely with its authors.

PY - 2019/5/15

Y1 - 2019/5/15

N2 - Metallic structures like circular plates or turbine discs feature special mode shapes that can be classified by nodal diameters and nodal circles. It is often desirable to experimentally examine just one mode shape with its distinct nodal diameter and nodal circle. To excite just one mode shape at a certain eigenfrequency the circumferential spectrum of the excitation force must not have other frequency content than the desired frequency and additionally have to resemble the mode shape itself. A device capable of creating such a single mode shape excitation has not existed yet. Here, a patented device is presented which is able to excite a single distinct mode shape of a rotating metallic circular structure. To achieve this the device features a toroidal horseshoe electromagnet with a variable gap geometry. By using the variable gap geometry and variable inductor current any modeshape of a metallic circular rotating structure can be excited. It is also possible to excite a combination of modeshapes by linear superposition of the necessary gap geometries. A brief explanation of the device is given followed by experimental results.

AB - Metallic structures like circular plates or turbine discs feature special mode shapes that can be classified by nodal diameters and nodal circles. It is often desirable to experimentally examine just one mode shape with its distinct nodal diameter and nodal circle. To excite just one mode shape at a certain eigenfrequency the circumferential spectrum of the excitation force must not have other frequency content than the desired frequency and additionally have to resemble the mode shape itself. A device capable of creating such a single mode shape excitation has not existed yet. Here, a patented device is presented which is able to excite a single distinct mode shape of a rotating metallic circular structure. To achieve this the device features a toroidal horseshoe electromagnet with a variable gap geometry. By using the variable gap geometry and variable inductor current any modeshape of a metallic circular rotating structure can be excited. It is also possible to excite a combination of modeshapes by linear superposition of the necessary gap geometries. A brief explanation of the device is given followed by experimental results.

KW - Cyclic symmetry

KW - Electromagnetic excitation

KW - Harmonic excitation

KW - Travelling wave

KW - Turbine disc

UR - http://www.scopus.com/inward/record.url?scp=85065989726&partnerID=8YFLogxK

U2 - 10.1007/978-3-030-12684-1_15

DO - 10.1007/978-3-030-12684-1_15

M3 - Conference contribution

AN - SCOPUS:85065989726

SN - 978-3-030-12686-5

SN - 978-3-030-12683-4

T3 - Conference Proceedings of the Society for Experimental Mechanics Series

SP - 153

EP - 162

BT - Topics in Modal Analysis and Testing, Volume 8

A2 - Mains, Michael L.

A2 - Dilworth, Brandon J.

PB - Springer Verlag

CY - Cham

T2 - 37th IMAC, A Conference and Exposition on Structural Dynamics, 2019

Y2 - 28 January 2019 through 31 January 2019

ER -