Neuber's rule accounting for the material nonlinearity influence on the stress concentration of the laminated composites

Since holes comprise the necessary features of many structural components, a comprehensive understanding of the behavior of composite plates containing an open hole is a crucial step in their design process. In the present manuscript, an extensive numerical study has been conducted in order to investigate the effects of material nonlinearity on the stress distribution and stress concentration factors in unidirectional and laminated composite materials. To attain this objective, various models with different configurations were studied. In unidirectional composites, the maximum deviation of stress distribution around the hole (from the linear solution) happens in 45 degrees lamina in which includes a high level of shear stress. However, the maximum difference in the stress concentration factor occurs in 15 degrees lamina and is 15.1% at the onset of failure. In composite laminates, the maximum deviation of nonlinear stress concentration factor from the linear solution is reported 24.3% and it occurs in [+45/-45](s) laminate. In the last section, Neuber's rule is employed to find the stress concentration factors of the laminated composites, with a reasonable accuracy.