Analysis of contact characteristics and dynamic response of joint interface with surface micro-grooved texture based on fractal theory

The surface texture has effectively mitigated stick–slip vibrations, but the underlying regulatory mechanisms remain fully elucidated. In response, this study sought to clarify the impact of surface texture on stick–slip vibrations by developing a fractal theory-based estimation model for joint interface contact stiffness and damping. The investigation began with experimental observations to assess stick–slip vibration effects induced by surface textures, followed by a theoretical analysis of the microscopic contact behavior associated with different texture densities, and then investigated the modulation of stick–slip vibrations by micro-grooved textures through a two-degree-of-freedom dynamic model. The results reveal that increasing surface texture density leads to a progressive decrease in stick–slip vibration intensity, transitioning to more regular, low-frequency vibrations. This effect is primarily due to changes in joint interface contact characteristics driven by surface texture, affecting contact stiffness and damping. As the texture area density increases, the effective contact area on the rough surface expands, influencing the deformation behavior of asperities, increasing contact stiffness, and reducing contact damping, thereby diminishing system stick–slip vibrations. The findings underscore the importance of joint interface contact characteristics—induced by surface texture—in influencing the dynamic response of mechanical systems. The developed model for estimating joint interface contact stiffness and damping offers a practical method for examining contact behavior and dynamic response on multiscale rough surfaces, and it provides valuable insights for designing surfaces to mitigate stick–slip vibrations effectively.