Poromechanics of freezing materials
Poromechanics of freezing materials
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DOI：
10.1016/j.jmps.2005.04.001
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发表时间：
2005-08-01
影响因子：
5.3
通讯作者：
Coussy, O
中科院分区：
文献类型：
--
作者：
Coussy, O
当在冰点以下均匀冷却时，水渗透的多孔材料经历由各种组合作用引起的低温变形：（i）液态水和冰晶之间的密度差，这导致在结晶开始时孔内压力的初始建立;（ii）不同组分之间产生的界面效应，其最终控制与孔进入半径分布有关的结晶过程;（iii）从冷冻部位排出的液态水向空气空隙的排出;（iv）低温抽吸过程，随着温度进一步降低，该过程将液态水向已经冷冻的孔隙驱动;（v）固体基质、液态水和冰晶之间的热机械耦合。我们制定了一个能够涵盖这整套行动的全面理论。宏观方法首先提供冻结多孔弹性材料的本构方程，包括界面能的影响。这种方法揭示了热力学状态函数的存在，即液体饱和度仅作为温度的函数。宏观冰依赖的孔隙弹性性能，然后升级的固体基质的弹性性能的知识，孔隙的访问半径分布，和毛细管曲线。最后，定量分析了冷却速度和孔径分布对渗水多孔材料低温变形的影响。该理论成功地解释了实验观察到的嵌入空气空隙的收缩，同时预测了当冷却突然停止时已经形成的冰的部分融化。(c)2005爱思唯尔有限公司保留所有权利。
When subjected to a uniform cooling below the freezing point a water-infiltrated porous material undergoes a cryo-deformation resulting from various combined actions: (i) the difference of density between the liquid water and the ice crystal, which results in the initial build-up of an in-pore pressure at the onset of crystallization; (ii) the interfacial effects arising between the different constituents, which eventually govern the crystallization process in connection with the pore access radius distribution; (iii) the drainage of the liquid water expelled from the freezing sites towards the air voids; (iv) the cryo-suction process, which drives liquid water towards the already frozen pores as the temperature further decreases; (v) the thermomechanical coupling between the solid matrix, the liquid water and the ice crystal. We work out a comprehensive theory able to encompass this whole set of actions. A macroscopic approach first provides the constitutive equations of freezing poroelastic materials, including the interfacial energy effects. This approach reveals the existence of a thermodynamic state function-namely the liquid saturation degree as a function of the temperature only. The macroscopic ice-dependent poroelastic properties are then upscaled from the knowledge of the elastic properties of the solid matrix, of the pore access radius distribution, and of the capillary curve. The theory is finally illustrated by analysing quantitatively the effects of the cooling rate and of the pore radius distribution upon the cryo-deformation of water-infiltrated porous materials. The theory succeeds in accounting for the experimentally observed shrinkage of embedded air voids, while predicting the partial melting of the ice already formed when the cooling suddenly stops. (c) 2005 Elsevier Ltd. All rights reserved.