Les vis pédiculaires sont couramment utilisées pour améliorer l’immobilisation de la colonne vertébrale dans le traitement de plusieurs maladies du rachis. Cependant, les taux de fractures de vis sont encore élevés de nos jours. Les efforts visant à assurer la conception et le choix des matériaux doit être encouragés.
A paper published in MECHANIKA. 2015 Volume 21(4): 272–276.
During the testing of the materials’ cavitation erosion resistance on vibratory systems by direct method (ASTM G32), the thread from the ultrasonic horn – test specimen connection, is subjected to fatigue. Operational experience has shown the occurrence of cracks and fractures in this area after a number of stress cycles that was lower than anticipated. The paper presents an analysis applied on four types of ultrasonic horns geometries: the original geometry with an external thread M12 and three modified geometries, with an internal thread M10 and M8. The four geometries were subjected to static analysis in order to determine the stress distribution. Based on static analysis, the behavior of the horns to fatigue was simulated and analyzed, determining the fatigue life, safety factors and optimal geometry.
