Using finite element model in calculation of stress concentration factor around an elliptical hole in composite hybrid lamina

The hybrid composites have exceptional properties such as strength to weight and hardness ratios. These characteristics make their application in the aerospace industry. In composite materials, there are various fittings, such as a bolt and a rivet, which are the focus of stress concentration in the joints because the fibers are damaged. In this research in hybrid composite materials, a high elastic modulus fiber (HM) and a low elastic modulus fiber (LM) are used. It is assumed that the length of the sheet is infinite. The force on the lamina is tensile force which is applied on matrix and fibers while the fibers in the layers are in the same direction. The effects of different parameters such as number of broken fibers and the ratio of (LM) to (HM) fiber extensional stiffness are examined. By using finite element method (FEM) and investigation geometrical and crack modeling, stress concentration factor (SCF) around an elliptical hole is calculated and compared with those reported in the literature. The results indicate the correctness of the code written for the analysis.