Magnetic Resonance Imaging Study of Water Absorption of Polymer Composite Materials Subjected to Mechanical and Temperature Impact

The results of a study of water absorption processes by samples of polymer composite materials
(PCMs) based on fiberglass, subjected to low-speed impact with controlled impact energy and alternating
temperature cycling are presented. Using magnetic resonance imaging (MRI), the distribution of absorbed
water in the fiberglass structure is visualized and the dynamics of its accumulation in various areas of the sample
are studied. It is found that mechanical impact leads to a nonuniform distribution of the absorbed water
in the samples and a significant accumulation of free water in the areas of destruction and adjacent layers in
the event of a violation of the integrity of the outer layer of the material. It is shown that cyclic alternating
temperature effects do not lead to a noticeable change in the water absorption processes and are comparable
in effect to mechanical nondestructive effects. The results obtained using MRI are in close agreement with
the data of traditional weight measurements, which shows the effectiveness of the method in diagnosing
defects and mechanical damage to PCMs exposed to the aquatic environment.