COMPRESSIVE FATIGUE OF FIBER COMPOSITES

FIBRE COMPOSITES may fail under compression-compression fatigue loadin g by microbuckling. A detailed analysis of fatigue failure is presente d, based on two alternative constitutive laws: the Mroz plasticity law and the Armstrong and Frederick ratchetting law. Failure is anticipat ed to occur by a low cycle fatigue process in materials which obey the Mroz law, and by plastic instability in materials which exhibit prono unced cyclic ratchetting. Predictions of the two theories are compared with available experimental data.