Dissertation > Excellent graduate degree dissertation topics show

Effect of Edge Contact of Metal-on-metal Hip Joint Replacements

Author: ChengZuo
Tutor: WangFengCai
School: Wuhan University of Science and Technology
Course: Mechanical Design and Theory
Keywords: Artificial hip Dynamic contact mechanics Edge contact Aspheric Finite Element
CLC: R687.4
Type: Master's thesis
Year: 2011
Downloads: 23
Quote: 0
Read: Download Dissertation

Abstract

The basis of artificial hip joint contact mechanism of lubrication and wear problems. In typical metal-on-metal artificial hip spherical bearings for specific research object, based on the development of the ball-based elastic contact theory and finite element model, equivalent to changing the the acetabular relative femoral head tilted state, applying dynamic displacement of the femoral head loads as well as changing the contact surface of the femoral head geometry simulation analysis of hip contact mechanics behavior of different walking posture, specifically through the following three analysis process in turn achieve: (1) is equivalent to changing the femoral head of inclination of the acetabular Analysis of joint prosthesis in various walking posture contact effect, especially for the acetabulum relative angle is too large may cause the edge of the contact behavior. The results showed that the acetabular inclination increase in the smaller range, its maximum contact pressure was the trend, the contact area has increased; When the acetabulum inclination exceeds a certain limit, the joint contact area close to the edge of the acetabulum, the contact pressure distribution form changed greatly, the maximum contact pressure distribution change, used to meet the balance of pressure distribution together with the external load. Artificial joint acetabular femoral head relative tilt easily cause different edge contact phenomenon; (2) dynamic simulation analysis of the artificial hip joint contact behavior in a given physiological displacement under the operating conditions and may induce the edge of the contact phenomena . Numerical simulations show that the vertical force component of the artificial hip edge dynamic contact process pressure force is smaller than the non-edge contact, but the horizontal component is significantly increased with the dynamic displacement. Dynamic contact with the edge of the case, the relative sliding and additional wear may cause the femoral head to the acetabulum medial; (3) non-ball reconstruction is using the corresponding program code for ball the base grid data model, and simulation analysis of different acetabular relative ellipsoid the femoral head tilted state of femoral head the contact mechanics performance of spherical acetabular this non-ball geometric characteristics hip. The results show that regardless of how the ellipsoidal ball femoral head alignment, in the contact area the center position of the average radius of curvature is increased within a certain range, can effectively reduce the maximum contact pressure of the contact surface, the contact area at the same time increases. Under the same load, acetabular inclined relative to the peak contact pressure of the state of the non-spherical femoral head and a smaller area of ??influence, but the pressure distribution is different. Control the non-ball of the hip joint, you can optimize the matching degree of the contact surface of the hip joint contact pressure distribution will help to improve. The joint contact directly determine performance wear lubricating effect. Study hip joint contact mechanics effect on clinical artificial hip wear assessment provides an analytical basis and joint contact conditions can be improved by adjusting the geometry of the contact surface, edge contact at the same time joint problems caused by the emphasis on clinical surgery and joint manufacturing .

Related Dissertations

CLC: > Medicine, health > Surgery > Orthopaedic Surgery ( movement system diseases,orthopedic surgery ) > Orthopedic surgery and surgery > Joint Surgery
© 2012 www.DissertationTopic.Net Mobile