Thermal Residual Stresses in Graded Ceramic Composites: A Microscopic Computational Model Versus Homogenized Models

Thermal residual stresses in ceramic composite laminates are analyzed through both a micromechanical computational model and two macroscopic homogenized models. The microscopic model is based on a purposely developed hybrid finite element able to account for the shape of the Alumina and Zirconia grains. Two different macroscopic models have been used as reference solutions for comparison: a standard displacement-based three-dimensional finite element model and an analytical model. Stress concentration factors, accounting for the microscopic material heterogeneities, have been estimated by means of the Eshelby tensor and applied to the average stress field obtained through the homogenized models.