Simplified semi-analytical method to calculate N-SIF of anisotropic composite plate with single edge notch

•A simple notch stress assessment formula was presented for orthotropic composite materials.•The relationship between singular intensity factor and N-SIF is constructed to calculate N-SIF.•The evaluation accuracy of N-SIF by the simplified formula is systematically verified. In order to simplify the assessment method of notch stress and N-SIF for single edge V-notched orthotropic composite plate, a semi-analytical formula based on equivalent intensity factor was presented based on linear elastic fracture mechanics. By equating geometric parameters, opening angle and material parameters as equivalent intensity factors of anisotropic composite materials, the theoretical formulas of notch stress field and N-SIF are simplified. On the basis of theoretical simplified formula, the equivalent intensity factor formula can be obtained by fitting a large number of numerical models for rapid evaluation of notch stress field. Furthermore, the relationship between equivalent intensity factor and N-SIF is constructed to quickly calculate the N-SIF of anisotropic composite materials. The error statistical results show that the dimensionless N-SIF obtained by the simple formula in this paper has high accuracy for anisotropic materials and can be applied to composite plates with different material parameters.