A new friction model for the ultrasonic vibration assisted deep drawing of the copper-nickel alloy sheet

This work aims to address the friction issue between copper-nickel alloy sheets and contact tools (vibrating at 20 kHz) in ultrasonic vibration (UV)-assisted deep drawing. A new friction model, dependent on sliding velocity (SV) and vibration amplitude (VA), is proposed: it revises the contributions of SV and VA to the friction coefficient (with VA reducing the coefficient drastically then flattening, and SV first increasing then decreasing it before flattening) and considers micro-scale interactions between the workpiece and tool surface. To study the friction characteristics and verify the model, experiments and numerical simulations were conducted to evaluate the effects of VA and SV on the friction coefficient; a finite element model using the new friction model was developed in ABAQUS to simulate UV-assisted deep drawing of cylindrical parts. The conclusion is that the predicted thickness distributions of the parts are in good agreement with experimental results, validating the accuracy of the proposed model.