Water diffusion behavior and transient internal stress analysis of steel/rubber composites

Abstract

This paper focuses on modeling the water absorption and the resulting internal stress behavior of steel/rubber composites. A three-dimensional finite element model, which includes the internal microstructure of bundled long steel wire reinforced composite, is established to accurately simulate water diffusion behavior. The water diffusion coefficient and rubber matrix's hygroscopic expansion parameter are estimated by experiments. The outcomes demonstrated that the earliest stages of water diffusion of steel/rubber composites conformed to the Fickian model. Then the weight gain continued to increase and followed the Langmuir model instead of Fickian model owing to the presence of bound water. Both the free water and bound water in steel/rubber composites were modeled by FE software. The internal stress caused by the differential swelling between steel and rubber was revealed and quantitatively analyzed through finite element simulation. The internal stress is the main cause of damage initiation in the steel/rubber composites, which was in good agreement with experimental measurements.