Influence of irregular fibre surface and debonding on the elastic properties of jute/epoxy composites: Micromechanics and finite element approaches

This study examines how irregular surfaces and debonding affect jute/epoxy composites. The study used micromechanics and finite element (FE) analysis to investigate properties such as elastic modulus in the longitudinal (E₁) and transverse (E₂) directions, major (ν₁₂) and minor (ν₂₁) Poisson’s ratios, and interfacial stresses (σ₁, σ₂, and τ₁₂, τ₂₃, τ₁₃). The FE models were validated using experimental and analytical results, which showed good agreement. Then, the FE model was extended to analyse the influence of different fibre volume fractions (V_f) on jute/epoxy composites with varied irregular surfaces (IRS%) and debonding (DBS%). The interfacial stress was compared across these variables. DBS% caused significant variation in E₂ and σ₂, while IRS% led to out-of-shear stresses that crossed the threshold. An increase in IRS% and DBS% at a constant fibre volume fraction did not significantly affect E₁. However, increasing V_f from 10–70% increased E₁ by 168%. E₂, on the other hand, decreased with V_f by 63–68%. Both IRS% and DBS% had a significant influence on interfacial stresses.