Measurement of Variation in Fracture Strength and Calculation of Stress Concentration Factor in Composite Laminates with Circular Hole

In this research, residual strength and stress concentration factor of laminated composites with a circular open hole are studied analytically, numerically and experimentally. the numerical study was carried out using the finite element method. moreover an analytical study was carried out with developing of point stress criterion. mechanical testing was performed to determine the un-notched tensile properties and notched strength of composite laminates and characteristic length to reinforcement of the notched strength of composite laminates are determined. results show that the influence of specimen dimension, notch size, lay ups and material properties are important on residual strength and stress concentration factor of laminated composite materials.