ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Effect of stacking sequence on mechanical, fatigue and impact behavior of kender-N/Cycasrevoluta hybrid fibreand waste grape stalk lignin toughened epoxy composites

Jeevanantham Subramanian, Kaliappan Seeniappan, Santhosh Mozhuguan Sekar, and Elango Natarajan

Department of Mechanical Engineering, Nehru institute of Engineering and Technology, Coimbatore, India

E-mail: jeevanantham694@gmail.com

Received: 22 April 2026  Accepted: 9 June 2026

Abstract:

This study evaluates the mechanical, fatigue, and impact behaviour of epoxy composites reinforced with hybrid Kender-N (blend of hemp and areca fibers in a 60:40 ratio)/midrib fronds of Cycasrevolutabiofibers and lignin particles, focusing on the influence of stacking sequence and filler content. Two laminate architectures were investigated: K/B/B/K (EF11–EF13), where Kender-N fiber mats formed the outer layers and Cycasrevolutabiofiber mats occupied the core layers, and B/K/K/B (EF21–EF23), where the stacking sequence was reversed. The numerical suffixes 1, 2, and 3 correspond to lignin contents of 1, 3, and 5 vol%, respectively. Mechanical testing and SEM analysis showed substantial performance improvements over neat epoxy.EF12 (K/B/B/K with 3 vol% lignin) exhibited the best overall mechanical performance, achieving tensile strength of 145 MPa, flexural strength of 162 MPa, and superior fatigue life, attributed to effective load-bearing by outer Kender-N layers, bio-fiber contribution to stiffness, and optimal lignin dispersion enhancing interfacial bonding. EF22 (B/K/K/B with 3 vol% lignin) demonstrated the highest impact resistance with 28.6 J energy absorption due to greater laminate compliance and efficient energy dissipation. SEM confirmed improved bonding at optimal filler loading, while agglomeration reduced performance at higher contents. These results highlight the importance of stacking design and optimal filler concentration for developing durable, high-performance sustainable hybrid composites suitable for structural and protective applications.

Keywords: Composites; Natural fibre; Particle; Mechanical properties; Fatigue behaviour; Damage analysis

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-05189-3

Chemical Papers 80 (11) 13421–13434 (2026)