Title: Beyond Homogeneity: Fiber Architecture Effects on the Structural Performance of Pultruded Thermoset Composites

Authors: Luohaoran Wang, Jacob Harris, Ali Zolali, Elias Shakour, Mihaela Banu

DOI:

Abstract: State-of-the-art composite modeling often assumes homogeneous fiber distributions, limiting the ability to capture local stress transfer and defect-driven performance variations. While recent studies have advanced fiber-resolved simulations, few incorporate realistic architectures under crash-relevant conditions. This work evaluated homogeneous, quadratic, hexagonal, and random fiber distributions using a targeted subscale framework, where individual fibers serve as proxies for fiber bundle arrangements to assess mechanical response and impregnation behavior. To understand the fiber interactions effect, models with a 60 % fiber volume fraction were developed and studied in actual situations such as battery separator beams in a side-pole crash loading. While homogeneous models predict lower apparent stress concentrations, fiber-resolved models reveal pronounced local stress amplification. Among the patterns studied, the quadratic arrangement exhibited lower stress concentrations than the hexagonal pattern due to reduced edge effect in resin rich region. Impregnation was evaluated using Computational Fluid Dynamics simulations of resin flow through different fiber architectures, with prescribed inlet flow conditions and resin viscosity as input parameters, and pressure drop, velocity fields, and effective permeability extracted as output metrics to assess impregnation capability. Among the patterns studied, the hexagonal arrangement exhibited the highest permeability (~1.4 × 10⁻¹⁴), while the random pattern showed restricted flow due to narrow inter-fiber gaps, resulting in limited preferential flow pathways. These findings highlight the role of fiber architecture in informing fiber guidance card design for lightweight pultruded composites, such as electrical vehicle (EV) battery separator beams. The proposed microstructure-driven framework will be validated in future work and lays the foundation for process-aware decision-making and digital twin development.

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Conference: SAMPE 2026

Publication Date: 2026/04/27

SKU: 32

Pages: 14

Price: $28.00