Squeak in hip endoprosthesis systems: An experimental study and a numerical technique to analyze design variants

Weiss, Cornelius; Gdaniec, Przemyslaw; Hoffmann, Norbert P.; Hothan, Arne; Huber, Gerd; Morlock, Michael M.

doi:10.1016/j.medengphy.2010.02.006

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Volume 32, Issue 6 , Pages 604-609, July 2010

Squeak in hip endoprosthesis systems: An experimental study and a numerical technique to analyze design variants

Cornelius Weiss
- Institute of Mechanics and Ocean Engineering, Hamburg University of Technology, Eissendorfer Str. 42, 21073 Hamburg, Germany
- Corresponding author. Tel.: +49 40 42878 2280.
Przemyslaw Gdaniec
- Institute of Mechanics and Ocean Engineering, Hamburg University of Technology, Eissendorfer Str. 42, 21073 Hamburg, Germany
Norbert P. Hoffmann
- Institute of Mechanics and Ocean Engineering, Hamburg University of Technology, Eissendorfer Str. 42, 21073 Hamburg, Germany
Arne Hothan
- Biomechanics Section, Hamburg University of Technology, Denickestr. 15, 21073 Hamburg, Germany
Gerd Huber
- Biomechanics Section, Hamburg University of Technology, Denickestr. 15, 21073 Hamburg, Germany
Michael M. Morlock
- Biomechanics Section, Hamburg University of Technology, Denickestr. 15, 21073 Hamburg, Germany

Received 2 March 2009; received in revised form 23 December 2009; accepted 11 February 2010. published online 17 March 2010.

Abstract

Hip endoprosthesis systems are analyzed with respect to their susceptibility to self-excited vibrations and sound or noise generation. Experimental studies reveal that certain configurations can become unstable causing exponentially growing regular high-frequency oscillations that asymptotically approach a limit-cycle with considerable amplitude. Ultimately the vibrations do also lead to the emission of sound that is perceived as squeaking or squeal. To identify dominant influence factors and critical parameters, stability analyses were conducted on the basis of finite-element modeling. The resulting numerical approach, based on the determination of complex eigenvalues and eigenvectors, is shown to be an effective tool to analyze and show differences between endoprosthesis designs with respect to their susceptibility to develop squeaking phenomenons.

Keywords: Squeaking, Hip endoprosthesis, Complex eigenvalue, Sliding instability