LAUSR

Abstract Frictional behaviour under oscillation-assisted forming was studied by the newly designed vibrating T-shape compression test under continuous re-lubrication condition. The friction factor in the oscillating bulk forming was identified from the inverse approach by iteratively calibrating the simulated deformed shape parameters to the experimental values. To increase the prediction accuracy of material response during oscillating motion of material, the elastic-plastic friction law and nonlinear elastic unloading and reloading behaviour in addition to the strain-rate dependent constitutive law were implemented in the finite element simulations for oscillating T-shape compression tests. Comparative sensitivity analyses were provided to study the influences of material model and oscillation parameters such as frequency, amplitude, and velocity of tool motions on the frictional behaviour. The present study shows that the reduction of friction factor in the oscillating forming can be explained by the continuous change of elastic recovery during the plastic deformation of workpiece and by the re-lubricated interface during the vibrational motion. The simulation can provide quantitative analyses for the effects of oscillation frequency, amplitude and punch velocity on the friction factor, which can be utilized for efficient process optimization of oscillation-assisted forming technology.