A Refined Analytical Model Incorporating Fiber Length, Orientation, and Loading-Angle Effects for Predicting the Young's Modulus of Short Fiber Composites

Liu J, Cai J, Fang R, Cai R, Yang G, Mu C, Nilsson F, Qu M (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Polymer Composites Wiley-Blackwell

DOI: 10.1002/pc.70995

Abstract

Predicting the modulus of short fiber-reinforced composites is complicated by simultaneous variations in fiber length, orientation, and volume fraction during processing. This work refines the classical modified rule of mixtures (MROM) by introducing two concentration-dependent weighting functions, (Formula presented.) and (Formula presented.), which capture the evolution of effective fiber length, fiber-fiber interactions, fiber orientation, and loading-angle effects. A microstructural efficiency coefficient (Formula presented.) is further incorporated to describe reinforcement degradation from dilute to crowded fiber conditions. The model was validated using ethylene-vinyl acetate/short carbon fiber composites with fiber volume fractions of 1.37%–16.80%. Young's modulus measured at loading angles of 0°, 45°, and 90° showed excellent agreement with predictions, with the refined formulation outperforming the classical MROM, particularly at higher loading angles. Overall, the refined framework provides a compact and physically grounded framework for accurately predicting stiffness and supports the design and optimization of short fiber-reinforced polymer systems.

Authors with CRIS profile

Guanda Yang Lehrstuhl für Werkstoffwissenschaften (Polymerwerkstoffe) (LSP)

Involved external institutions

Beijing Oriental Yuhong Waterproof Technology Co., Ltd. / 东方雨虹 CN China (CN) Royal Institute of Technology / Kungliga Tekniska Högskolan (KTH) SE Sweden (SE) Guangdong Polytechnic Normal University CN China (CN)

How to cite

APA:

Liu, J., Cai, J., Fang, R., Cai, R., Yang, G., Mu, C.,... Qu, M. (2026). A Refined Analytical Model Incorporating Fiber Length, Orientation, and Loading-Angle Effects for Predicting the Young's Modulus of Short Fiber Composites. Polymer Composites. https://doi.org/10.1002/pc.70995

MLA:

Liu, Jinchuan, et al. "A Refined Analytical Model Incorporating Fiber Length, Orientation, and Loading-Angle Effects for Predicting the Young's Modulus of Short Fiber Composites." Polymer Composites (2026).

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