Theoretical and Numerical Investigations of Swelling Phenomena of Hydrated Porous Media

生物材料如硬组织和软组织、人工材料如水凝胶或地质材料如粘土和页岩的宏观行为受微观尺度上的多尺度微观结构、耗散现象和各种电化学-力学耦合的控制。此外，流动无关的（固有的）粘弹性固体基质的强烈耦合与流体相关的粘性效应，从液压和电化学梯度。因此，得到一个完全耦合的电化学力学问题，包括膨胀，反之亦然，收缩现象在绝对有限的变形。基于多孔介质理论（TPM），本项目的目标是提供一个适当的公式来描述固体-流体聚集体的理论和数值，其中负电荷固定在固体骨架上，正离子和负离子包含在孔隙流体中。该项目的创新与我们的荷兰合作伙伴Jacques Huyghe博士的热模拟提案密切相关，该项目的创新在于完全耦合的电化学力学模型在水合固体的绝对有限三维粘弹性变形下的理论公式化和基于FE工具PANDAS的FEM框架中的多相模型的数值处理。

The macroscopic behaviour of biomaterials like hard and soft tissues, artificial materials like hydrogel or geomaterials like clay and shale ist governed by the multiphysic microstructure together with dissipative phenomena and various electrochemomechanical couplings on the microscale. Furhtermore, flowindependent (intrinsic) viscoelastic properties of the solid matrix are strongly coupled with the flow-dependent viscous effects resulting from hydraulic and electrochemical gradients. Thus, one obtains a fully coupled electro-chemomechanical problem including swelling and, vice versa, shrinking phenomena at absolutely finite deformations. Based on the Theory of Porous Media (TPM), it is the goal of this project to deliver a proper formulation of both the theoretical and the numerical description of a solid-fluid aggregate, where negative charges are fixed to the solid skeleton and positive and negative ions are includetd into the pore-fluid. The innovation of the this project which is closely related to a thermatically neighboured proposal by our Dutch partner Dr. Jacques Huyghe lies in both the theoretical formulation of a fully coupled electro-chemomechanical model at absolutely finite 3-dimensional viscoelastic deformations of the hydrated solid and the numerical treatment of the multiphasic model in the framework of the FEM based on the FE tool PANDAS.