Raman spectroscopy - a technique to assess the residual stress in fiber-reinforced polymeric insulation materials

Fiber reinforced polymeric insulation materials are composite insulating materials that are made from high-performance polymeric insulation material and high-performance fibers. This makes reinforcement of fiber-reinforced polymeric insulation material of interest in many structural insulation applications subject to high voltage or ultra high voltage environment. In this paper, the effect of residual stresses on the electrical insulation integrity is first summarized followed by the description of the laser Raman spectroscopy technique for the assessment of the residual stress in high-performance fiber reinforced polymeric insulation. The present investigation is concerned with the use of the laser Raman spectroscopy to analyze the residual stresses in a Twaron®-type aromatic polyamide (aramid) fibers/Araldite® epoxy resin system.