Multi-objective optimization of friction temperature and friction torque for multi-conical friction clutches based on hybrid surrogate model and NSGA-II

The operational performance and service life of multi-conical friction clutches are governed by their transient thermal behavior, which is related to interface contact, frictional heat generation, and convective heat dissipation. To enhance thermal uniformity and torque transmission capacity, this study presents an integrated multi-objective optimization framework that combines transient thermo–fluid coupling analysis, a hybrid surrogate modeling approach, and the NSGA-II evolutionary algorithm. A three-dimensional transient thermal–fluid model is first developed to characterize the temperature distribution on the friction interface. Then, an advanced surrogate model is established by merging Kriging, radial basis function, and polynomial response surface techniques, ensuring predictive accuracy and computational efficiency. Dedendum height, addendum height, face width, and cone angle are selected as the four primary geometric design parameters. The NSGA-II algorithm is utilized to achieve simultaneous optimization of peak temperature, radial temperature difference, and transmitted torque, yielding a set of Pareto-optimal solutions. A weighted preference-based scheme is subsequently applied to select the most balanced configuration. The optimized clutch structure exhibits a 33.31% increase in friction torque, a 29.28% reduction in radial temperature difference, and a 9.82% decrease in peak temperature. Moreover, the optimized design demonstrates robustness under harsh conditions such as high-speed and heavy-load conditions, improving temperature uniformity and operational stability. This method reveals the tribological mechanisms between structural parameters, frictional heat generation, and heat dissipation. It provides an efficient solution for improving the thermal and transmission performance of multi-conical clutches and offers theoretical support and engineering reference for the design of transmission components.