【摘要】 基于对松质骨结构特征的观察 ,应用建立在连续介质力学框架内的混合物理论基础上的两相多孔介质模型来描述人体胫骨端松质骨在撞击载荷作用下 ,固体骨质的应力场、变形场与孔间骨髓压力分布随时间变化的规律 ,研究流固之间的耦合关系。考虑固体骨质为各向同性线弹性介质 ,流体为理想流体 ,结合相应的初、边值条件 ,建立了描述松质骨撞击动力问题的一组完整的控制方程。然后 ,采用Galerkin加权残值法 ,通过在连续方程中引入压力 ρ与罚参数 β之比项 ,消去控制方程中的压力项 ,导出了松质骨在撞击载荷作用下的动力响应的罚有限元公式。用编制的有限元程序计算了松质骨平面问题的撞击动力响应。结果表明 :由于松质骨中液体组分的扩散和流动 ,引起固体骨质和液态骨髓间的相互作用 ,使得松质骨呈现着一种强烈的表观粘弹性行为以及能量耗散性质。更多还原

【Abstract】 Biphasic porous medium model,based on the mixture theory in continuum mechanics frame,is used to depict the distribution disciplinarian of solid phase’s stress field,distortion field and fluid phase’s pore pressure when the cancellous bone tissue is subjected to impact loading via experimental observations for the cancellous bone structure.The coupling relationship among the distortion and fluid flow is studied.Together with corresponding initial and boundary conditions,the solid osseous is considered as isotropic elastic medium,and the marrow in the cavity as ideal fluid,the dynamic governing equations are working out.The finite element formulation is attained for the dynamical response of cancellous bone by using Galerkin weighted residual method.Penalty finite element formulation,which is obtained via introducing ratio term of pressure p and peralty parameter β in the continuity equation and,in turn,the pressure in governing equations is eliminated.As a exapmle,the coupling effect between the solid phase and the fluid phase in cancellous bone is calculated about the plane problem when the tissue is subjected to impact loading.The computational results show that the reciprocity between the solid osseous and the marrow in the cavity is resulted in because of coupling effcts between the solid and the fluid.The concellous bone is provided with certain features similar to those occuring in viscoelastic solids and in energy dissipation.更多还原