Analysis, finite element simulation and experimental investigation of friction in tube hydroforming

The purpose of this work is to present a new analytical method for determination of the coefficient of friction in hydroforming of tubes, based upon the tube-upsetting test. According to the developed method, the friction coefficient can be calculated by using the geometrical data from the deformed tube and material properties without force measurement. Influence of different process parameters on the tribological phenomena has been observed and analyzed. The proposed method has been verified by comparison with the results obtained by FE-simulation and by experiment.