Influence of Nitric Acid and Water on GFRP under Flexural-Tensile Combined Stress

Abstract

Glass fiber reinforced plastic (GFRP) is widely used for various products even in the railway field because it has superior physical performance of electrical insulation. GFRP is used as the core parts of the circulating current prevention type pull-off arms and there were some examples of GFRP-breaking accidents. Most of the surface of the broken GFRP exhibited a smooth brittle fracture. In actual field, acid and water are considered to be the factors affecting the core conditions of pull-off arms. Therefore, in order to reproduce the actual condition, the authors developed and carried out the tests in which the solution (nitric acid and water) and mechanical stress were combined. As a result, the influence of nitric acid and water on GFRP was little when no mechanical stress was applied. However, when mechanical stress is applied, the influence of nitric acid is more significant. The mechanical strength of GFRP decreased dramatically and the surface of the broken GFRP exhibited a smooth brittle fracture.