Finite Element Simulation And Experimental Research On The Unconfined Compression Of Cartilage Tissue

With the society population aging and the increasing of injury caused by accident, the incidence of osteoarthritis and articular cartilage injury becomes increasing, and does serious harm to human health and life quality, bringing heavy burden to family and society. Once articular cartilage injury occurs, it is hard to recover by itself. The research on the the relationship between material structure and its mechanical properties is of great significance to the arthropathy prevention, clinical diagnosis and pathological study. Meanwhile, it also has instructive significance to articular cartilage repair(mainly refers to artificial joint replacement and cartilage tissue engineering).This paper first does finite element simulation of the unconfined compression of articular cartilage. According to the special physiological structure of articular cartilage, the author comprehensively considered its solid phase, liquid phase and fibril reinforced phase, its layered structure and its dilatation-dependent permeability, built a fibril reinforced poroelastic model. Based on the proposed model, and by utilizing ABAQUS software and FORTRAN language, the geometric model, the physical model and the solving algorithm were extended and coupiled, and the model were verified by unconfined ramp compression. This paper reveals articular cartilage load-bearing mechanism and stress-relaxation properties, and studied the effects of different composing material parameters on its mechanical properties.In the experimental aspect, the author improved and debugged the biomechanical-property measuring system, measured different strain and strain-rate-dependent response of porcine cartilage tissue in unconfined compression combined with data acquisition system. Utilizing MATLAB and PSI-PLOT data processing software, the relationship between stress-strain and equilibrium modulus under different strain and strain-rate are investigated. At last, comparative analysis is implementing between the articular cartilage fibril reinforced poroelastic model and experiment in unconfined ramp compression. The author also compared and analysed the mechanical properties between the prepared PVA-HA composite hydrogel, chitosan tissue engineering scaffold and the porcine cartilage tissue.