A STUDY OF THE INFLUENCE OF MICROSTRUCTURE ON THE MODIFIED EFFECTIVE MODULUS APPROACH FOR COMPOSITE LAMINATES

Although the effective modulus (EM) representation of composite materials is widely used in the stress analysis and design of structural laminates, there is little understanding of the meaning of EM stress distributions in regions of high stress gradients. This study presents a modified effective modulus (MEM) approach to elucidate the comparison between EM stress distributions and exact solutions in such regions. In prior work, the authors demonstrated that the MEM approach effectively compares EM and exact solutions for a laminate with a single fiber size. The objective of this study is to explore the effect of fiber size on the MEM approach. The methodology involves examining how fiber size impacts the interpretations of EM stress fields by applying a comparative analysis with heterogeneous or micromechanics (MM) models. The findings indicate that variations in fiber size influence the performance and reliability of the MEM approach, highlighting its relevance for accurate stress analysis in structural components with complex geometries. This study contributes to a deeper understanding of laminate behavior under non-uniform stress conditions, which is crucial for the design and analysis of composite structures.