Napjatostní a spolehlivostní analýza destruovaných keramikých hlavic

Stress and reliability analyses of damaged ceramic femoral heads

článek ve sborníku ve WoS nebo Scopus

en

Today, the problem of reliability of the hip joint ceramic heads becomes important, since world-wide the destruction of the ceramic head has generally been stated in a non-negligible number of patients. Therefore stress and reliability analyses of the ceramic heads were made using experimental and computational modelling aimed at finding the causes of the head destruction. The deformation and stresses are obtained by computational methods (finite elements) under testing conditions, in accordance with ISO 7206-5. Head reliability is based on the Weibull weakest link theory. The head's stress and reliability are significantly influenced by manufacturing inaccuracies of the cone contact areas. The considered manufacturing inaccuracies are modelled as axisymmetric or 3D. The effects of manufacturing inaccuracies on the head's hoop stress and the head's contact pressure along the contact taper are analysed in detail, because the maximum tensile stress acts in this region. Finally, the effect of the mentioned manufacturing inaccuracies on the head's failure probability during the loading is shown. The results obtained are used in clinical practice and in the technological processes of stem and ceramic head manufacturing.

Příspěvek se zabývá destruovanými keramickými hlavice kyčelní endoprotézy.

Today, the problem of reliability of the hip joint ceramic heads becomes important, since world-wide the destruction of the ceramic head has generally been stated in a non-negligible number of patients. Therefore stress and reliability analyses of the ceramic heads were made using experimental and computational modelling aimed at finding the causes of the head destruction. The deformation and stresses are obtained by computational methods (finite elements) under testing conditions, in accordance with ISO 7206-5. Head reliability is based on the Weibull weakest link theory. The head's stress and reliability are significantly influenced by manufacturing inaccuracies of the cone contact areas. The considered manufacturing inaccuracies are modelled as axisymmetric or 3D. The effects of manufacturing inaccuracies on the head's hoop stress and the head's contact pressure along the contact taper are analysed in detail, because the maximum tensile stress acts in this region. Finally, the effect of the mentioned manufacturing inaccuracies on the head's failure probability during the loading is shown. The results obtained are used in clinical practice and in the technological processes of stem and ceramic head manufacturing.

Damages femoral heads, computaional modelling, Production inaccuracies

2002

15.10.2002

WIT Press, UK

Southampton

1-85312-926-7

Damage and Fracture Mechanics VII

11