A model of mechanical contacts in hearing aids for uncertainty analysis

Ester Creixell Mediante, Jonas Brunskog, Jakob Søndergaard Jensen, Martin Larsen

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

Abstract

Modelling the contact between assembled parts is a key point in the design of complex structures. Uncertainties at the joint parameters arise as a result of randomness in physical properties such as contact surface, load distribution or geometric details. This is a challenge of concern in the hearing aid field, where the small lightweight structures present vibration modes at frequencies within the hearing range. To approach this issue, a model of contacts based on lumped elements is suggested. The joint parameters are the stiffness of a series of spring elements placed along the contact surface, which are obtained by minimizing the least squares distance between experimental and modelled modal frequencies of the complete structure. A key point of the method is the reduction of the size of the system by means of a substructure synthesis method, which reduces the computational cost of the optimization. Another strong point is that an experimental modal analysis of the structure is not required, but only the resonant frequencies and deflection shapes are needed. A case study where the contact between two assembled plastic parts is examined is presented. The variability of the resonant frequencies of the assembly due to changes in the physical properties of the contact is characterised by means of experimental measurements. The distributions of the identified contact model parameters are found to be related to the variability of the resonant frequencies.
Original languageEnglish
Title of host publicationProceedings of Novem 2015
Number of pages14
Publication date2015
Article number48913
Publication statusPublished - 2015
EventNoise and vibration Emerging Technology 2015 - Excelsior Hotel, Dubrovnik, Croatia
Duration: 13 Apr 201515 Apr 2015

Conference

ConferenceNoise and vibration Emerging Technology 2015
LocationExcelsior Hotel
CountryCroatia
CityDubrovnik
Period13/04/201515/04/2015

Cite this

Creixell Mediante, E., Brunskog, J., Jensen, J. S., & Larsen, M. (2015). A model of mechanical contacts in hearing aids for uncertainty analysis. In Proceedings of Novem 2015 [48913]