Research On Mechanical Properties And Viscoelasticity Of Porcine Patella Articular Cartilage Through Indentation

Articular cartilage is a kind of hyaline cartilage,which is not only very smooth,but also has elasticity.This characteristic makes the articular cartilage can fully play the important role of buffering stress,absorbing shock,lubricating the joint surface and preventing wear during joint movement.The excellent mechanical properties of articular cartilage and the increasing articular cartilage disease make the study of mechanical properties of articular cartilage urgent.Studying the biomechanical properties of articular cartilage can not only help us to understand the prevention and treatment of osteoarthrosis,but also can provide a mechanical reference for the biomimetic articular cartilage materials used for cartilage repair.These research results are of great significance for human treatment of cartilage-related diseases.In addition,due to the more complex loading conditions in the indentation test,including load,compression,shear and other load modes,it can more accurately simulate the loading state of cartilage in actual work.The main research and analysis methods of articular cartilage and the characteristics of biomaterials are reviewed and analyzed.Then the mechanical properties tests of porcine patella articular cartilage using indentation test technology were clarified.The main tasks completed by this paper are as follows:(1)The indentation experiment of porcine patella articular cartilage was carried out.The effect of storage conditions,loading methods,and the parameters of the indenter on its mechanical properties was studied using displacement-controlled loading.The study found that the mechanical properties of the different storage conditions are significantly different;and at the same indentation depth,when the loading rate increases from 5?m / s to 50?m / s,the greater the measured elastic modulus;when the indentation loading rate is consistent,The elastic modulus of the flat-ended indenter with a diameter of ?0.6 mm was measured to be the largest,the flat-ended indenter with a diameter of ?0.8 mm was the next,and the flat-ended indenter with a diameter of ?1.0 mm was the smallest.(2)A data processing method based on strain rate is proposed,and this method is used to compare and collate indentation data under different experimental conditions.It was found that the greater the strain rate,the greater the measured elastic modulus.Based on this,the advantages and disadvantages of three kinds of viscoelastic models of SLS,DMW,and TMW in fitting indentation data were studied.Based on the indentation experimental curve fitting of the Prony series,the viscoelastic mechanical response of the cartilage articular during the indentation experiment were analyzed.