Sensitivity Analysis of the Material Parameters Obtained from the Measurements

0535263 - ÚT 2021 RIV CZ eng C - Conference Paper (international conference)
Fuis, Vladimír
Sensitivity Analysis of the Material Parameters Obtained from the Measurements.
PROCEEDINGS OF THE 2018 18TH INTERNATIONAL CONFERENCE ON MECHATRONICS - MECHATRONIKA (ME). Brno: Institute of Electrical and Electronics Engineers Inc., 2018 - (Maga, D.; Stefek, A.; Brezina, T.), s. 505-510, č. článku 8624693. ISBN 978-80-214-5544-3.
[International Conference on Mechatronics - Mechatronika (ME) /18./. Brno (CZ), 05.12.2018-07.12.2018]
Institutional support: RVO:61388998
Keywords : material parameters * measurement * principal stress * sensor – strain gauge * sensitivity analysis * Weibull's weakest link theory
OECD category: Mechanical engineering

The paper deals with sensitivity analysis of the material parameters of the ceramic material on the dispersion of the measured data from the sensors. Material parameters of ceramic material are calculated from a set of destruction tests of ceramic heads of total hip joint replacements. The standard way of calculation of the ceramic material parameters consists in carrying out a set of 3 (or 4) point bending tests of specimens which were cut out from parts of the ceramic material to be analysed. In case of ceramic heads of the prosthesis, it is not possible to cut out specimens of required dimensions because the heads are too small. On that score, a special testing jig was made, in which 40 heads were destructed. From the measured values of circumferential strains of the head’s external spherical surface under destruction (by the sensors – strain gauges), the state of stress in the head under destruction was established using the finite elements method. From the obtained values the material parameters of the ceramic material were calculated using Weibull’s weakest-link theory. The calculated material parameters (Weibull modulus m and normalized volume strength σo, the last material parameter – stress σu is assumed to be equal 0 and corresponds to the conservative approach) has the dispersion and the influence of this dispersion (in our case the dispersion ± 5 % is assumed) is analysed in detail.
Permanent Link: http://hdl.handle.net/11104/0315825