Finite Element Simulation for Material Wear of the Cover-Ball Contact Structures

• Main Authors: HSU CHIH HSIANG, 許志祥
• Other Authors: J.S.S.Wu
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/45377533939095975234

碩士 === 國立中興大學 === 機械工程學系 === 87 === Measurements are usually used to study the wear problems occurred in the mechanical contact components. However, such measurements are rather expensive in either time or the instrumental investment. Besides, results of the measured wear data are mostly disputable. Here, in the study of the wear problems occurred in the discontinu-ous, contact structures using the finite element strategy, two points are considered: (1) Problem of solving the energy transfer difficulties be-tween the discontinuous, contact structures; This is solved by proper fi-nite element formulations on basis of the contact normal and shear stresses, and (2) Problem of deriving the wear quantities; This is solved by using the Archard wear law. In this study, numerical simulations for the analysis of the wear in three-dimensional contact structures during long-time, reciprocal sliding motion may thus be developed and signifi-cant results are provided and discussed. The most severe problems in total hip arthroplasty are components loosening and the wear of polyethylene acetabular components, which may cause the arthroplasty to fail. Such wear problems in the process of the replacement of the artificial hip joints (AHJ) is quite often and popu-lar after surgery. The friction of the contact region between the polyeth-ylene cup and prostal bone-head in the AHJ mainly causes these wear phenomena which is most like a cover-ball bearing structure. Finite ele-ment models for such bearing-like structure in AHJ are developed and related results, e.g., the amount of wear, the depth of wear, the wear stresses, etc.. In general, the wear data obtained after arthroplasty in most of the published papers, either from clinical collection or experimental results, distributes too wide to be used as the designing criteria of the AHJ. How-ever, optimum and reliable designing criteria to avoid loosening along with the wear happened in the AHJs provided here are quite significant. The data provided here may thus give longer life for the replacement of AHJs. The current results compared to some available physical properties of wear, come out the singnificance of the algorithms and models devel-oped. Similar wear problems of any other machine elements can also be refereed use the formulations and solving procedures discussed in this paper.