Contact Mechanics And Lubrication Analysis Of Artificial Hip Joints With Different Material Combinations

The joint material is widely available in the clinical surgery of the hip joint replacement：metal, ceramics, as well as polyethylene. The different materials group with the appropriatecontact mechanics is particularly important in the joint bio-manufacturing project, a reasonableselection of materials group is contribute to the improvement of the artificial joint bio-frictionproperties. This article will select typical materials of metal cobalt chromium molybdenum alloy(CoCrMo), typical of ceramic materials, alumina (Al2O3) and polyethylene (UHMWPE) materialas the object of study, take the metal-on-metal(MOM), metal-on-ceramic (MOC),ceramic-on-ceramic(COC), ceramic-on-polyethylene(COP), metal-on-polyethylene (MOP) fivedifferent material groups to the appropriate contact mechanics performance analysis andcomparison to understand the different material groups with total hip contact characteristics ofmanufacturing engineering for joint biological and understanding their friction and wearperformance reference. Mainly through the following three analysis process in order to achieve:(1) Impose a static shock to the hip joint with different materials matching. Equivalentsimulation contact effect of the artificial hip joint under load. Analysis the contact mechanicalproperties and wear prediction of artificial hip joints with different materials matching under thesame load. Experiments show that choosing too large and too small elastic modulus of thematerial used in artificial hip joint is not ideal. By experiments selected materials of artificial hipjoint to anslyze contact stress. The choice of metal-on-metal (MOM) and metal-on-ceramics(MOC) can get a better contact mechanical performance.(2) According to the normal human gait, the human hip joints bear load curve in normalwalking gait. Analyze the artificial hip joints contact pressure by finite element method and drawthe contact pressure curve. Predicting the most prone to wear gait phase by the contact pressurecurve. Numerical simulations show that the single foot support body in walking gait is the mostprone to wear.(3) According to the human hip joints bear load curve, sliding velocity between femoralhead’s contact surface and certabular’s contact surface and the formula of hemrock andDowson’s minimum film thickness, assessment the lubrication state of artificial hip joints.Predict the wear state of artificial hip joints by the lubrication effect. Similar such as metal-on-metal, ceramic-on-ceramic, Metal-on-ceramic and so on, lubrication state of hard materialsartificial hip joints is mixed lubrication and boundary lubrication. Polythene material as theacetabular of artificial hip joints, the lubrication state is boundary lubrication.