One-dimensional transient hygrothermoelastic field in a porous strip considering nonlinear coupling between heat and binary moisture

• Published in: Journal of Thermal Science and Technology Vol. 11; no. 3; p. JTST0035
• Main Authors: ISHIHARA, Masayuki, OGASAWARA, Keita, OOTAO, Yoshihiro, KAMEO, Yoshitaka
• Format: Journal Article
• Language: English
• Published: Tokyo The Japan Society of Mechanical Engineers and The Heat Transfer Society of Japan 01.01.2016; Japan Science and Technology Agency; The Japan Society of Mechanical Engineers
• Subjects: Binary moisture; Coupling; Diffusion; Finite difference method; Hygrothermal stress; Mathematical analysis; Moisture content; Nonlinear coupling; Nonlinearity; Plane stress; Porous media; Porous medium; Residual stress; Strip; Vapors
• ISSN: 1880-5566; 1880-5566
• DOI: 10.1299/jtst.2016jtst0035

This study aims to develop practical tools for the mechanical design of porous media subjected to a broad gap in a hygrothermal environment. The one-dimensional transient hygrothermoelastic field in a porous strip is investigated considering the nonlinear coupling between heat and binary moisture. The derivation of the system of governing equations is summarized first, by considering the nonlinear relation between temperature, dissolved moisture content, and vapor concentration and diffusivities of both dissolved moisture and vapor. The nonlinearity between the temperature, dissolved moisture content, and vapor concentration is investigated qualitatively and quantitatively. Next, the system of governing equations is applied to the infinite strip subjected to broad gaps of temperature and dissolved moisture content and solved by the finite difference method. The distributions of temperature, dissolved moisture content, vapor concentration, and dissolution rate were illustrated numerically, and the moisture distribution was found to be highly nonlinear. Finally, based on hygrothermoelasticity, the distribution of the resulting in-plane stress in a strip free from mechanical constraints is analyzed theoretically. The occurrence of residual stress, which is quite unlike what it is under the linear theory, is confirmed. Finally, the effect of gaps in a hygrothermal environment on the residual stress is investigated qualitatively and quantitatively.