An anisotropic damage constitutive model for needled ceramic matrix composites was proposed based on continuum damage mechanics. The effects of both tensile damage and shear damage were considered in the model. The stress-strain curves of the material were obtained by tensile and shear tests and the parameters of the constitutive model obtained by curving-fitting. Then the model was written into commercial finite element software by user subroutine. Both calculated tensile and shear curves agreed with the test curves

and the maximum errors were 5.62% and 1.47% respectively. With both damage constitutive model and elastic model

an adjustment sheet of an aero-engine exhaust nozzle was calculated to analyze the mechanical response under complex aerodynamic load and temperature load. The stress distributions calculated by the two models were similar

but the value of damage constitutive model was obviously lower than that of the elastic model.