For the simulation of the material degradation process of 3D textile-reinforced composites during multi-axial fatigue loading a new physically based damage model is developed based on the fracture mode concept (FMC) of CUNTZE and the continuum damage mechanics. The determination of the model parameters and the model verification is done in cyclic tests of glass/epoxy tube specimens, with multi-layered weft knitted fabric reinforcement, under superposed tension/compression-torsion loading.