Exploring the Mechanical Behavior of Modern and Ancient Egyptian Yarns through X-ray Microtomography and Finite-Element Methods
Topic(s) : Material and Structural Behavior - Simulation & Testing
Co-authors :
Rajakumaran VASUKI (FRANCE), Johnny BEAUGRAND (FRANCE), Sofiane GUESSASMA (FRANCE), Alessia MELELLI (FRANCE), Alain BOURMAUD (FRANCE)Abstract :
Flax fiber is a natural fiber, known for its high strength, stiffness, and low density, making it a popular choice for use in various industrial and textile applications. Flax fibers, extracted from the flax plant, undergo processes like retting, breaking, scutching, and hackling to separate and refine them. They are twisted together to produce yarns. The investigation of their tensile characteristics is critical for understanding their mechanical behaviour and assisting in improving the quality of flax yarns used in composite and textile products.
This study demonstrates the comprehensive numerical tensile analysis carried out on both Modern Egyptian yarns (MEY) and Ancient Egyptian yarns (AEY) to determine their tensile characteristics. The understanding of mechanical properties of ancient Egyptian flax fibers is very important for modern flax fibers to be foreseen as competitive substitution to synthetic materials in composite industry. The AEY dating back to 2140-1976 BC and the MEY cultivated in Egypt (Malika variety) in the year 2023 were used. Analyzing the strength of AEY provides important information on the materials, manufacturing process, and durability of these materials. In particular, 3D images help us understand the techniques ancient Egyptians used to create them and reveal details like Kink-bands and porosity [1]. Additionally, these images show us how the yarns degraded over time.
A 3D finite element (FE) model was constructed utilizing static 3D images obtained from Synchrotron X-ray microtomography. The primary objective was to discern how stress is distributed in MEY and AEY during tensile loading. The axial stress values reached up to 350 MPa for MEY, while for AEY, the axial stress peaked at 80 MPa. Notably, the considered model is linear and elastic, lacking a damage criterion. The Representative Volume Element (RVE) approach was utilized in the study for managing yarn heterogeneity. The computed apparent modulus of MEY original was 19 GPa, but it varied from 32 GPa to 21 GPa for RVE models. In contrast, the apparent modulus for AEY original was 5 GPa, and for RVE models, it ranged from 2 GPa to 9 GPa. Due to the yarn's non-uniformity, significant stress heterogeneity was observed. By comparing MEY and AEY, it was observed that the inter-fiber airiness was higher in AEY. Furthermore, the contribution of bundles under tensile loading was lower in AEY due to the discontinuity of fiber bundles. This discontinuity is linked to the degradation of fibers and middle lamella in AEY (Figure 1). The findings offer insight on the effects of ancient fiber degradation on tensile strength and stress distribution, leading to a denser knowledge of the mechanical behavior of both MEY and AEY.
This study demonstrates the comprehensive numerical tensile analysis carried out on both Modern Egyptian yarns (MEY) and Ancient Egyptian yarns (AEY) to determine their tensile characteristics. The understanding of mechanical properties of ancient Egyptian flax fibers is very important for modern flax fibers to be foreseen as competitive substitution to synthetic materials in composite industry. The AEY dating back to 2140-1976 BC and the MEY cultivated in Egypt (Malika variety) in the year 2023 were used. Analyzing the strength of AEY provides important information on the materials, manufacturing process, and durability of these materials. In particular, 3D images help us understand the techniques ancient Egyptians used to create them and reveal details like Kink-bands and porosity [1]. Additionally, these images show us how the yarns degraded over time.
A 3D finite element (FE) model was constructed utilizing static 3D images obtained from Synchrotron X-ray microtomography. The primary objective was to discern how stress is distributed in MEY and AEY during tensile loading. The axial stress values reached up to 350 MPa for MEY, while for AEY, the axial stress peaked at 80 MPa. Notably, the considered model is linear and elastic, lacking a damage criterion. The Representative Volume Element (RVE) approach was utilized in the study for managing yarn heterogeneity. The computed apparent modulus of MEY original was 19 GPa, but it varied from 32 GPa to 21 GPa for RVE models. In contrast, the apparent modulus for AEY original was 5 GPa, and for RVE models, it ranged from 2 GPa to 9 GPa. Due to the yarn's non-uniformity, significant stress heterogeneity was observed. By comparing MEY and AEY, it was observed that the inter-fiber airiness was higher in AEY. Furthermore, the contribution of bundles under tensile loading was lower in AEY due to the discontinuity of fiber bundles. This discontinuity is linked to the degradation of fibers and middle lamella in AEY (Figure 1). The findings offer insight on the effects of ancient fiber degradation on tensile strength and stress distribution, leading to a denser knowledge of the mechanical behavior of both MEY and AEY.