Numerical-experimental investigation of the tensile behavior of continuous NiTi wire–reinforced epoxy composites

Purpose The purpose of this study is to investigate hybrid polymer composites reinforced with shape memory alloy (SMA) wires, as they are promising materials for structural applications combining load-bearing capability with adaptive functionality. Design/methodology/approach In this research, multicomponent-reinforced hybrid NiTi–epoxy composites were produced through a hand layup method using Nitinol wires. The authors studied two wire diameters (0.5 and 1 mm) and three reinforcement configurations comprising one, two and three parallel wires. To obtain stress–strain responses and derive elastic properties, quasi-static tensile tests were performed. Statistical validation involved coefficient of variation, analysis of variance (analysis of variance, α = 0.05) and uncertainty analysis. The experiments were simulated using a finite element model in LS-DYNA with a calibrated martensitic SMA constitutive model. Findings The obtained results indicate that tensile strength and stiffness increase with increasing wire diameter as well as the number of reinforcement layers. The best performance was achieved with the three 1-mm wire configuration, which showed increases of 30.47 MPa and 5.15 GPa in tensile strength and Young’s modulus, respectively. Numerical predictions were consistent with experimental results in an average deviation of 5.6%. The results indicate that an increase in reinforcement layers improves orthotropic stiffness, while larger fiber inclination angles decrease load-bearing efficiency, presenting reliable design guidance for advanced NiTi-reinforced smart composite structures. Originality/value Unlike previous studies that primarily focus on short SMA fibers or lack statistical validation, this work systematically quantifies the combined effects of continuous wire diameter and reinforcement count on the mechanical performance.