摘要
目的采用有限元仿真和实验对比分析关节软骨的承载机理和应力松弛效应。方法考虑关节软骨基质固相、孔隙液相和胶原纤维增强相,并综合考虑软骨分层结构以及关节软骨渗透率随固体基质膨胀率变化特性,建立关节软骨纤维增强多孔弹性有限元模型。基于该模型,应用ABAQUS软件和FORTRAN语言编程嵌套,对关节软骨无约束阶梯压缩进行有限元仿真。应用自行研制的生物力学性能测试系统,通过阶梯加载实验对生猪软骨有限元分析结果进行了实测对比。结果试件以0.45%/s应变速率阶梯加载时,在试件中心,液相可维持承载80 s左右,最大可承担近90%的总应力。结论基于纤维增强多孔弹性有限元模型的无约束阶梯压缩有限元分析可定量评价关节软骨的固、液两相承载能力随应变和时间的变化特性。结合软骨无约束压缩实验的仿真分析有助于更准确地评价软骨的力学性能。
Objective To analyze the load-bearing mechanism and stress-relaxation properties of the articular car- tilage （AC） through finite element simulation and experimental validation. Methods By comprehensively consid- ering the solid phase of the matrix, the liquid phase of the pore and the reinforced phase of the collagen fibrils in AC, as well as the dilatation dependent permeability of AC, a fibril reinforced poroelastic （FRPE） model was built including changes of void ratio with subsurface depth of the AC. Based on the proposed model, and by utilizing ABAQUS software and FORTRAN language, the finite element analysis （FEA） on unconfined ramp compression of AC was conducted. The equilibrium modulus of porcine cartilage tissues under unconfined compression was measured by a self-designed biomechanical property measuring system, and the results between the FEA and the unconfined ramp compression test of the AC were compared. Results The liquid pore pressurization could last about 80 seconds and contributed up to 90 % of the total stress at the middle point of the test specimen when it was compressed at a strain rate of 0.45%/s. Conclusions The FEA on the unconfined ramp compression of AC based on the FRPE model can quantitatively evaluate the load bearing capacity of the solid and liquid phase, respectively, changed with different strain and loading time. Simulation analysis combined with the unconfined ramp compression test results facilitates the evaluation on mechanics properties of the cartilage with more accura- cy.
出处
《医用生物力学》
EI
CAS
CSCD
北大核心
2012年第6期630-635,共6页
Journal of Medical Biomechanics
关键词
关节软骨
无约束压缩
有限元分析
力学特性
应变
应力
Articular cartilage
Unconfined compression
Finite element analysis
Mechanical properties
Strain
Stress
