Tailored flax-reinforced composites : properties and sustainable applications

Bencze, Andrei (author), Bergant, Zoran (author), Arnăutu, Irina (author), Šturm, Roman (author), Chlada, Milan (author), Steigmann, Rozina (author), Stanciu, Mariana Domnica (author), Savin, Adriana (author)

Tailored flax-reinforced composites (TFRC) are being investigated as a sustainable alternative to conventional glass- and carbon-fiber-reinforced composites, having a lower fiber volume than these and the structure of the laminate with two plies (two identical layers of alkali-treated flax yarns) is unidirectional, weakly twisted, oriented at ±45°, and reinforced by stitching; it is also impregnated with bio-resin and has robust reinforcement through controlled lamination. TFRC has shear-dominated behavior under both tensile and compressive loading, due to the off-axis orientation of the fibers, but the damage evolution differs significantly. Under tensile loading, the material exhibits a lower strength (55.2 MPa), whereas under compression loading, the composite achieves a higher apparent strength (99.1 MPa). The paper provides a comprehensive analysis for structural and mechanical characterization using the following: nondestructive evaluation using ultrasound to detect internal discontinuities and assess homogeneity; optical microscopy to evaluate fiber–matrix integration and porosity reduction; and Dynamic Mechanical Analysis to assess thermomechanical transitions and storage modulus stability. Finite element simulations have been used to determine elastic properties and validate the matrix-dominated shear response. The results confirm that the [±45°]4S sequences of TFRC optimize mechanical response and interfacial adhesion, promoting TFRC as an ecological solution for structural systems where progressive energy dissipation is preferred.

• Language: English
• Keywords: biocomposites, flax fibers, flax-reinforced composites, sustainability, mechanical properties, dynamic mechanical analysis
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 28 str.
• Numbering: Vol. 18, issue 17, art. 2069
• PID: 20.500.12556/RUL-186063
• UDC: 66.02
• ISSN on article: 2073-4360
• DOI: 10.3390/polym18172069
• COBISS.SI-ID: 288947971
• Publication date in RUL: 26.08.2026

Record is a part of a journal

• Title: Polymers
• Shortened title: Polymers
• Publisher: MDPI
• ISSN: 2073-4360
• COBISS.SI-ID: 517951257

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: biokompoziti, lanena vlakna, kompoziti, trajnost, dinamična mehanska analiza