Cohesive Strength of Materials during Drying Processes

Abstract

This article is a contribution to modeling and analysis of the cohesion strength of saturated porous bodies during drying processes. The dependence of the drying-induced state of stress, the overall (reduced) stress, and the admissible stress on moisture content is discussed. The strength criterion is proposed stating that possible cracking of the material during drying takes place in regions where the reduced stress exceeds the critical admissible value for the given moisture content. Numerical calculations of the drying-induced stresses were carried out for a convectively dried kaolin cylinder, and the regions of possible material cracking within the cylinder were determined. This theoretical prediction of the possible cracking place in the material is consistent with the experimental data previously presented by the authors.

Keywords:

• Convective drying
• Cracking
• Drying-induced stresses
• Modeling
• Numerical calculations

ACKNOWLEDGEMENTS

This work was carried out as a part of the research project NN 208 02 20 434 sponsored by the Ministry of Science and Education of Poland.