Micro-pleating in carbon-carbon composites under a cyclic load

The mechanical behavior of three-dimensional integral braided carbon-carbon composites (C/C) has been explored under unconventional fatigue loading, and a series of special experimental phenomena were observed. In this present paper, one of these phenomena, the micro silk-like pleating of the pyrocarbon matrix, is discussed. With thermodynamic analysis, it is shown that small areas of high-temperature contribute to the micro-pleating formation. Moreover, slight friction between pyrocarbon laminates has been proven to produce the small high-temperature areas during cyclic tensile loading.