Effects of Material Mechanical Properties on Wall Thickness Variation in Numerical Control Rotary Draw Bending Process of Tubes

Based on the platform of ABAQUS/Explicit, a three-dimensional elastic-plastic finite element model of the numerical control (NC) rotary draw bending of 21-6-9 high strength stainless steel tube with the specification of 15.88 mm×0.84 mm was established, and the reliability of the model was validated. Then the effects of mechanical properties of the stainless steel on the wall thickness variation rates during the NC rotary draw bending were investigated by finite element simulation with the established model. The results show that the wall thickness variation rate of the bend tube decreased with the increase of strength coefficient and hardening exponent or with the decrease of yield strength of the stainless steel, while elastic module and Poisson′s ratio had little influences on the wall thickness variation rates. The sensitivity of the wall thickness variation rate to material mechanical properties was from high to low in the order of strength coefficient, hardening exponent, yield strength, elastic module and Poisson′s ratio.