| Abstract: | Scanning electron microscopy and x-ray diffraction analysis are used to study the morphology of several aramid and polyimide fibers developed in Russia and to determine their strain-strength characteristics. It is shown that the supermolecular structure of the fiber in large part determines the character of its interaction with the matrix and behavior during failure of the fiber composite (FCP). In the case of aramid fibers, composite failure is accompanied by intensive fibrillation leading to lamination on a microscopic scale and a deterioration in the service characteristics of the composite. The stability of the investigated polyimide fibers against fibrillation and microlamination, in combination with good heat resistance, makes them promising as reinforcing materials for FCPs.Submitted for the Tenth International Conference on the Mechanics of Composites (Riga, April 1998).Institute of High-Molecular-Weight Compounds of the Russian Academy of Sciences (St. Petersburg, Russia) and the  Khimvolokno Scientific-Industrial Association (Mytishchi, Russia). Translated from Mekhanika Kompozitnykh Materialov, Vol. 33, No. 5, 656–669, September–October, 1997. |
