关键词: 自锁螺母, 收口工艺, 螺母几何特性, 有限元仿真

Abstract: Self-locking nuts,known for their excellent vibration resistance,anti-loosening properties,and reusability,are widely used threaded fasteners in the aerospace industry. However,due to the complex deformation mechanism and numerous influencing parameters in the closure area of self-locking nuts,the impact of closure process and nut geometry on the mechanical performance during installation is not yet clear. In this study,serial finite element models of the closure and tightening processes of self-locking nuts made of three typical materials were established. The effects of closure segment height,closure amount,closure method,and other parameters on the final tightening torque and stress-strain behavior of self-locking nuts after installation were investigated using a single-factor control method. According to the results,during the closure process of self-locking nuts,increasing the closure amount and adopting an elliptical closure method lead to increased plastic deformation of the threads at the bottom of the closure segment,resulting in a corresponding increase in the tightening torque during assembly. When the closure amount is 0.5 mm,the closure height is 4.2 mm,and an elliptical closure method is used,the locking performance of the self-locking nut is optimized.

Key words: self-locking nut, closing process, nut geometric characteristics, finite element simulation