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 the application of these materials in the aerospace industry. In composite materials, there are various fittings, such as a bolt and a rivet, which is 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 also assumed that the length of the sheet is infinite. The force on the lamina is tensile force which applies on matrix and fibers while the fibers in the layers are one directed. In this paper the effects of different parameters such as ,number of broken fibers and the ratio of (LM) to (HM) fiber extensional stiffness.By using finite element method (FEM) modeling and investigation geometrical and crack modeling, stress concentration factor (SCF) around a elliptical hole is calculated and compared with the results obtained from reference.The results of the validation showed that compared to the reference data are close to each other, indicating the correctness of the code written for the analysis.