Data for: Maximum Likelihood Analysis on Size Effect Weibull-based Models for the Tensile Strength of High-Performance Single Fibers

Efficient use of fibers in composite materials requires a precise understanding of the factors governing their mechanical performance. Among these, the size effect, or the dependence of fiber tensile strength on size, remains not fully characterized. The conventional two-parameter Weibull model often fails to capture this dependence accurately. In this study, Weibull models incorporating fiber length, surface area, and volume were applied to three high-performance fibers: LCP-1, Aramid-1, and Amide-1. The analysis clarifies discrepancies in previous reports that relied on limited datasets or single fiber types without direct model comparisons. Tensile tests were performed according to ASTM C1557 and D3822 standards, and Weibull parameters were estimated via Maximum Likelihood Estimation with bootstrapped confidence intervals (10,000 iterations). Results show that tensile strength decreases with increasing fiber length, confirming a size effect. The length-, surface area-, and volume-based Weibull models exhibited statistically indistinguishable fits, indicating comparable predictive capability. The findings highlight the need for larger sample sizes to obtain stable Weibull parameters and provide a unified framework for comparing fiber size effects in composite design.