Multiscale computation on mechanical environment of chondrocytes / 医用生物力学

Objective To compare the mechanical environment of chondrocytes between superficial zone and deep zone by multiscale computation. Methods The chondrocyte biphasic model was set up and made the results of the articular cartilage (AC) biphasic model mapped to the corresponding borders of the chondrocyte model as the boundary condition. The chondrocyte model was computed to obtain the results of the mechanical environment of chondrocytes and analyzed. Results The results showed that the stress of chondrocytes at deep zone was half of that at superficial zone, but both were much smaller than those outside chondrocytes. The pericellular matrix (PCM) sustained the high stress outside chondrocytes and remarkably reduced the stress inside chondrocytes. Interstitial flow directions adjacent to two chondrocytes were totally the opposite.Conclusions The bearing property of AC reduced the stress near chondrocytes at deep zone prominently and protected the chondrocytes at deep zone and subchondral bone. PCM sustained the high stress outside chondrocytes to provide lower stress environment for chondrocytes living. The opposite interstitial flow direction of two chondrocytes supported the theory that synovia seepage from cartilage surface and nutrient pumped out from subchondral bone constitute the bidirectional nutrient supply in AC.

Numerical computation on the scaffolds models with regular square holes using nonlinear fluid-solid-coupling approaches / 医用生物力学

Objective The influencing parameters of solid and fluid computing fields for the scaffolds models with regular square holes were discussed by nonlinear fluid-solid-coupling approaches, the numerical computational results of which the models were regarded as both rigid body and non-linear elasticity were compared as well. Method one direct fluid-solid-coupling approach and two indirect fluid-solid-coupling approaches were adopted, and the calculating reliability of three kinds of fluid-solid coupling methods were verified. Results The solid-fluid-coupling computational results are obtained in light of 12 kinds of scaffolds which were constructed by 3 groups of square side length (50,100 and 150μm) and 4 groups of porosity (61%,65%,77% and 84%). The field parameters of those solid models including stress, strain and displacement and those fluid models including static pressure, velocity, wall shear stress and strain rate are achieved and compared.Conclusions A quiet difference between the results of porous scaffold models as a rigid body and that of non-linear elasticity. The different porosity with the same pore radius or the different pore radius with the same porosity effected the field parameters of solid models and fluid models in varying degrees.

Numerical computation on the scaffolds models with regular square holes using nonlinear fluid-solid-coupling approaches / 医用生物力学

Objective The influencing parameters of solid and fluid computing fields for the scaffolds models with regular square holes were discussed by nonlinear fluid-solid-coupling approaches.The numerical computational resuits of which the models were regarded as both rigid body and non-linear elasticity were compared as well.Method One direct fluid-solid-coupling approach and two indirect fluid-solid-coupling approaches were adopted,and the calculating reliability of three kinds of fluid-solid coupling methods was verified.Rasults The solid-fluidcoupling computational results are obtained in light of 12 kinds of scaffolds models which are constructed by 3 groups of square side length(50,100 and 150 μm)and 4 groups of porosity(61%,65%,77%and 84%).The field parameters of those solid models including stress,strain and displacement and those fluid models including static pressure,velocity,wall shear stress and strain rate are achieved and compared.Conclusion There appear some difference between the results of porous scaffold models as a rigid body and as non-linear elasticity.The different porosity with the same pore radius or the different pore radius with the same porosity would affect the field parameters of solid models and fluid models in varying degrees.

Numerical computation on the scaffolds models with regular square holes using nonlinear fluid-solid-coupling approaches / 医用生物力学

Objective The influencing parameters of solid and fluid computing fields for the scaffolds models with regular square holes were discussed by nonlinear fluid-solid-coupling approaches.The numerical computational resuits of which the models were regarded as both rigid body and non-linear elasticity were compared as well.Method One direct fluid-solid-coupling approach and two indirect fluid-solid-coupling approaches were adopted,and the calculating reliability of three kinds of fluid-solid coupling methods was verified.Rasults The solid-fluidcoupling computational results are obtained in light of 12 kinds of scaffolds models which are constructed by 3 groups of square side length(50,100 and 150 μm)and 4 groups of porosity(61%,65%,77%and 84%).The field parameters of those solid models including stress,strain and displacement and those fluid models including static pressure,velocity,wall shear stress and strain rate are achieved and compared.Conclusion There appear some difference between the results of porous scaffold models as a rigid body and as non-linear elasticity.The different porosity with the same pore radius or the different pore radius with the same porosity would affect the field parameters of solid models and fluid models in varying degrees.

Numerical computation on the scaffolds models with regular square holes using nonlinear fluid-solid-coupling approaches / 医用生物力学

Objective The influencing parameters of solid and fluid computing fields for the scaffolds models with regular square holes were discussed by nonlinear fluid-solid-coupling approaches.The numerical computational resuits of which the models were regarded as both rigid body and non-linear elasticity were compared as well.Method One direct fluid-solid-coupling approach and two indirect fluid-solid-coupling approaches were adopted,and the calculating reliability of three kinds of fluid-solid coupling methods was verified.Rasults The solid-fluidcoupling computational results are obtained in light of 12 kinds of scaffolds models which are constructed by 3 groups of square side length(50,100 and 150 μm)and 4 groups of porosity(61%,65%,77%and 84%).The field parameters of those solid models including stress,strain and displacement and those fluid models including static pressure,velocity,wall shear stress and strain rate are achieved and compared.Conclusion There appear some difference between the results of porous scaffold models as a rigid body and as non-linear elasticity.The different porosity with the same pore radius or the different pore radius with the same porosity would affect the field parameters of solid models and fluid models in varying degrees.