Description of anisotropy and chemo-mechanical interaction in porous materials

本研究涉及一类多孔材料的非弹性变形描述。重点放在两个基本问题上，即力学性能的各向异性和与化学-力学相互作用有关的降解现象。主要应用领域包括结构力学和地质力学。 固有各向异性的主题将在宏观上异质的材料的背景下，特别是结构砌体和钢筋混凝土。本文首先对砖砌体的非弹性变形进行描述。一个连续的配方将开发和材料功能将通过微观力学分析确定。宏观框架将被应用于评估的关键砌体组件的水力发电设施在北方魁北克的地震稳定性。将进行额外的研究，在该地区的混凝土与嵌入式套钢筋的机械响应建模。这里，再次，将追求耦合的微观/宏观机械方法。该研究将特别相关的核工业，特别是对核安全壳结构的结构完整性的评估受到极端的机械/热负荷。 许多天然和人工制造的材料由于化学相互作用而经历机械性能的显著退化。研究将主要集中在化学-机械耦合存在下的白垩变形特性的建模。降解现象归因于晶间压溶。这是一个发生在颗粒接触处的非平衡过程，包括固体材料通过间隙流体的扩散输送而溶解和去除。将制定一个总体宏观框架。将采用均质化程序来描述潜在的物理化学过程。这里的主要应用领域是石油工程。

This research is related to description of inelastic deformation in a class of porous materials. The emphasis is placed on two fundamental issues, i.e. that of anisotropy of mechanical properties and the degradation phenomena that are linked to chemo-mechanical interaction. The primary areas of application involve structural mechanics and geomechanics.    The topic of inherent anisotropy will be addressed in the context of materials that are heterogeneous on the macroscale; in particular, structural masonry and reinforced concrete. The research will focus first on the description of inelastic deformation of brick masonry. A continuum formulation will be developed and the material functions involved will be identified through a micromechanical analysis. The macroscopic framework will be applied to assess the seismic stability of critical masonry components of hydroelectric power generation facilities in Northern Quebec. Additional research will be conducted in the area of modeling of mechanical response of concrete with embedded sets of reinforcement. Here, again, a coupled micro/macro-mechanical approach will be pursued. The research will be particularly relevant to the nuclear industry, especially to the assessment of structural integrity of nuclear containment structures subjected to extreme mechanical/thermal loads.    A number of natural and manufactured materials undergo a significant degradation of mechanical properties as a result of chemical interaction. The research will focus mainly on modeling of deformation characteristics of chalk in the presence of chemo-mechanical coupling. The degradation phenomenon will be attributed to intergranular pressure solution. This is a non-equilibrium process that occurs at the grain contacts and consists of dissolution and removal of solid material by diffusive transport through the interstitial fluid. A general macroscopic framework will be developed. A homogenization procedure will be employed to describe the underlying physico-chemical processes. The primary area of application here is the petroleum engineering.