%0 Journal Article %A Das, Shuvrangsu %A Castaneda, Pedro Ponte %D 2019 %I Begell House %K polycrystal, brine-air inclusions, texture, compressibility %N 2 %P 121-150 %R 10.1615/IntJMultCompEng.2019029125 %T A MULTIPHASE HOMOGENIZATION MODEL FOR THE VISCOPLASTIC RESPONSE OF INTACT SEA ICE: THE EFFECT OF POROSITY AND CRYSTALLOGRAPHIC TEXTURE %U https://www.dl.begellhouse.com/journals/61fd1b191cf7e96f,1c64c2e535b20529,6753007b7c434784.html %V 17 %X Sea ice is a multiphase composite material with complex microstructure and viscoplastic rheology. At length scales much smaller than the size of a typical floe, sea ice consists of aggregates of hexagonal closed packed (HCP) ice crystals with embedded inclusions of brine and air. Although there can be significant variations depending on the age and depth of the ice, the dominant structure at this scale consists of columnar grains displaying a pronounced texture where the (c)-symmetry axes of the single crystal grains lie in the horizontal plane, but with random orientations in this plane. Because the HCP ice crystals exhibit highly anisotropic viscoplastic behavior, with "easy" glide on basal planes orthogonal to the (c)-axis and "hard" slip on nonbasal systems, this strong texture has significant implications for the anisotropy of the macroscopic response of intact sea ice. On the other hand, the brine-air inclusions, which are modeled as voids with elongated shapes in the vertical direction, are also expected to have significant implications for the rheological response of sea ice, most importantly, by endowing sea ice with overall compressibility. In this work, use is made of the iterated fully optimized second-order homogenization method to develop a constitutive model for the macroscopic viscoplastic response of sea ice accounting for the abovementioned microstructural variables. Comparisons to experimental results from the literature demonstrate the capabilities of the model, especially in terms of capturing the dilatational response of intact sea ice under combined hydrostatic and deviatoric mechanical loading. %8 2019-07-05