Electrical and Photographic Techniques for Measuring Microcracking in Some Fiber Reinforced Plastics
In an effort to find new techniques for detecting and measuring the microcracking process in fiber reinforced plastic composites, detectable electrical effects and, in some cases, luminescence have been observed. The nature of these effects at present is not fully known. However, knowledge of their existence makes possible the use of electrical and photographic techniques for investigating microcracking in fiber/plastic composites. This paper describes several experimental techniques that have been utilized and presents quantitative results for several composite materials of current interest. Determination of the potential usefulness of these techniques will require additional knowledge of the nature of the effects and detailed correlation with the composite microcracking process. Further work should be directed toward these ends.