Thermomechanical modeling of friction stir blind riveting for CF/PEEK–AA6061 stacks

This study proposes an innovative thermodynamic analysis method for the friction stir blind riveting (FSBR) of carbon fiber-reinforced thermoplastics (CFRTP) and aluminum alloy stacks. The proposed model comprehensively incorporates both the viscoplastic heat generated within the sticking-affected zone of the workpiece and the interfacial frictional heat between the workpiece and the rivet. Building upon these thermal mechanisms, temperature-dependent material yield strength and friction coefficient functions were integrated into the analytical framework, thereby establishing a fully thermo-mechanically coupled model for the FSBR process. Experimental validation demonstrated good agreement between model predictions and measured values of temperature, penetration force, and torque, with maximum relative errors of 6%, 9%, and 15%, respectively. Comparative analysis indicates that accounting for viscoplastic heat primarily influences the temperature field within a localized region approximately 0–6 mm from the rivet. Neglecting viscoplastic heat sources in the numerical model leads to a significant increase in prediction errors for penetration force and torque compared to experimental data.