Numerical Simulation on Thermal Curing Behavior and Defect Formation Mechanism Analysis of Basalt Fiber-Reinforced Polymer Core Rods for Composite Cross-Arms

The production of basalt fiber-reinforced polymer (BFRP) core rods for composite cross-arms in power transmission lines currently suffers from high defect rates—including internal porosity, surface cracking, under-curing, and thermal yellowing. Although BFRP exhibits superior mechanical strength, thermal stability, and corrosion resistance compared with conventional glass-fiber-reinforced polymers, industrial-scale manufacturing of BFRP core rods remains immature; critically, the spatial–temporal evolution of thermal curing behavior inside the mold has not been systematically characterized. This knowledge gap relies on costly, time-consuming trial-and-error process tuning. This study develops a validated numerical simulation method grounded in an autocatalytic curing kinetics model, calibrated using differential scanning calorimetry (DSC) experiments, to quantitatively predict the spatiotemporal distribution of temperature and degree of cure during pultrusion-based BFRP core rod fabrication. Four key curing metrics—final surface degree of cure, pre-cure degree, peak core temperature, and through-thickness cure gradient—are identified and rigorously evaluated against critical process parameters (pultrusion speed, pre-cure and cure zone temperatures, and axial temperature gradient) via an L9 orthogonal experimental design. The model elucidates four distinct defect formation mechanisms, thereby reducing empirical dependence and accelerating the reliable industrial deployment of BFRP core rods in composite cross-arm systems.