FE simulation of dieless drawing process for small-size non-circular tubes

摘要

Dieless drawing process was applied to small-size non-circular tubes. Deformation behavior of cross section of the fabricated tubes was investigated using finite element (FE) simulation. The FE simulation with coupled thermomechanical analysis using a commercial code; MSC MARC/Mentat was conducted considering strain rate sensitivity of the material tubes. In the calculation, the material properties were dealt with as a function of temperature in a special subroutine, whose constitutive equation considering strain rate sensitivity and strain hardening was used. Consequently, the effect of drawing condition on the deformation behavior of the tubes was clarified. Additionally, it was found that the geometrical similarity law in cross section was satisfied for small-size non-circular tubes. On the contrary, the geometrical similarity law in cross section is not satisfied in some cases that the length of heating coil is narrow. Therefore it is found that a certain level of deformation zone length on the basis of temperature distribution is necessary to satisfy the geometrical similarity law in cross section.