The Marchetti-Vicenzi’s nail is an intramedullary device that allows inserting into a long bone six flexible nails that elastically expand and stabilize the fracture. In this numerical work an MBS flexible model of the device has been developed, with the dual purpose of evaluating forces between the bone and the system’s components during its progressive opening and verifying the loaded behaviour of the stabilized bone. The complexity of the analysis arises from the large deformations which mechanical elements undergo throughout ring sliding phases and from the displacement and variability of the contact points, not known a priori, between the elements. Different solutions, for flexible body modelling, have been analysed (discretization with lumped parameters, ‘flexible body’, ‘FE Part’) and compared in terms of accuracy of achievable results and required computational resources. Contact parameters calibration and the use of simplified geometries have allowed simulating all the process within a reasonable time. From results analysis, some critical issues of the designed nail and information for new prototypes development have emerged.
DESIGN OF AN INTRAMEDULLARY NAIL WITH ELASTIC DISTAL ANCHORAGE
PASCOLETTI, GIULIA
;F. Cianetti;E. M. Zanetti
2018
Abstract
The Marchetti-Vicenzi’s nail is an intramedullary device that allows inserting into a long bone six flexible nails that elastically expand and stabilize the fracture. In this numerical work an MBS flexible model of the device has been developed, with the dual purpose of evaluating forces between the bone and the system’s components during its progressive opening and verifying the loaded behaviour of the stabilized bone. The complexity of the analysis arises from the large deformations which mechanical elements undergo throughout ring sliding phases and from the displacement and variability of the contact points, not known a priori, between the elements. Different solutions, for flexible body modelling, have been analysed (discretization with lumped parameters, ‘flexible body’, ‘FE Part’) and compared in terms of accuracy of achievable results and required computational resources. Contact parameters calibration and the use of simplified geometries have allowed simulating all the process within a reasonable time. From results analysis, some critical issues of the designed nail and information for new prototypes development have emerged.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
