Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : October 07, 2017 - October 09, 2017
In fluid machinery operation, besides cavitation impact load, other external loads such as centrifugal force and hydraulic pressure do exist. These loads could generate not only cavitation erosion but also cracks on the machine components. To repair these damages, coating technology utilizing epoxy resin materials is often applied. However, the damage behavior of epoxy resin under a mixed condition of cavitation and external loads has not been understood comprehensively. In the present work, evaluation on the crack growth mechanism in epoxy resin specimen under both tensile load and cavitation impact was conducted. An experimental apparatus for conducting the test was specially manufactured so that a tensile load can be applied at the same time with a cavitation load to the specimen. An initial crack was firstly made in the specimen. Them, the tensile-cavitation tests were done inside a tank filled with distilled water with fixed temperature. When only cavitation was applied to the specimen, the initiated crack did not propagate while erosion damages were generated on the surface. When only tensile load was applied, the initiated crack propagated slowly. Moreover, the growth rate increased as the load was increased. However, when both tensile load and cavitation impact were applied, the crack growth rate was significantly accelerated. The crack growth rates at this condition were then quantified and compared.
