Dynamic Investigation of Interface Stress on Below-Knee Residual Limb in a Prosthetic Socket

The dynamic effects of inertial loads on the interface stresses between a residual limb and the trans-tibial prosthetic socket were investigated. A 3-D nonlinear finite element model, based on the actual geometry of the residual limb, including internal bones and socket liner, was developed to study the mechanical interaction between the socket and the residual limb during walking. To simulate the friction/slip boundary conditions between the skin and liner, automated surface-to-surface contact was used. The results show that interface pressure and shear stress have a similar double-peaked waveform shape in the stance phase. The average difference in interface stresses between the cases with and without consideration of inertial forces is 8.4% in the stance phase and 20.1% in the swing phase. The results suggest that the dynamic effects of inertial loads on interface stress distribution during walking must be considered in prosthetic socket design.

水凝胶在多相离子溶液中的力电化学行为

为分析多相离子溶液中智能材料水凝胶的力电化学耦合行为,提出了一种简单耦合分析方法。该方法将多相混合介质理论的基本方程分解为具有简单耦合关系的两个问题:电化学平衡问题和两相流动问题。以稳态压差下的渗透问题为算例,对生物软组织材料和水凝胶的力电化学响应进行了数值分析。计算结果表明,该方法能有效地分析生物软组织材料的响应并对水凝胶的响应提出预测。