Abstract: The fracture of composite eutectic is accumulated by micro-damage started from dangerous point. The damage feature is connected with distribution of fibers in composite eutectic. The longitudinal, transverse and shear damage variables are defined by the damage complementary free energy. Based on the microstructure characteristics of composite eutectic with parallel fibers, the expressions of damage variables is determined and damage flexibility tensor is calculated. Considering such tensor and the local stress field of composite eutectic, the damage strain field of composite eutectic is obtained and the maximum damage strain is determined. On account of the maximum strain theory, the loading function is defined, and the micro-damage strength model of composite eutectic with parallel fibers is built. According to the fracture strength expression of composite ceramic with no damage eutectic, the fracture strength of composite ceramic with damage eutectics is gotten. The size dependence of the fracture strength is analyzed. The result showed that as the numerical value of damage variables increases, the fracture strength of composite ceramics may lessens, and the size dependence range of the fracture strength may smaller.

Key words: composite eutectic;damage variable;damage flexibility tensor;damage strain field;maximum strain theory;damage strength model, Feature size, Girth of Last, Laplacian deformation, Parametric design, Shoe last