Influence of low-frequency vibration on friction coefficient of contact interface in bend-stretch forming

Abstract

Low-frequency vibration assisted bend-stretch forming has a good friction reduction effect due to the “surface effect” and enhances the forming ability of materials compared to traditional bend-stretch forming. In order to further improve the friction state of the forming contact interface, the contact interface friction between AL6005A aluminum alloy and Q345B steel under low-frequency vibration was analyzed by using the elastic-plastic contact theory. The formula for calculating the sliding friction coefficient of contact pressure and low-frequency vibration parameters was established. The influence of forming contact pressure and vibration frequency on the contact stress, friction force, and friction coefficient of asperity at the contact interface is obtained through the simulation analysis of low-frequency vibration sliding friction of double rough contact surface. The results show that the application of low-frequency vibration can weaken the influence of contact pressure on the friction coefficient and reduce the friction coefficient between AL6005A aluminum alloy and Q345B steel. Within a specific range of contact force, the sliding friction coefficient decreases first and then increases with the increase of vibration frequency. There is a critical vibration frequency to minimize the sliding friction coefficient of the contact interface.

Keywords

• Low-frequency vibration
• Friction coefficient
• Bend-stretch forming
• Aluminum alloy profiles
• Fractal theory