Research on the sensitivity of material parameters to cross-sectional deformation of thin-walled rectangular tube in rotary draw bending process

The fluctuation of material parameters and coupling effects of them have significant effects on cross-sectional deformation of rectangular tube in rotary draw bending process. So, in this research, a global sensitivity analysis (GSA) system was established based on the combination of Morris’ GSA method and 3-D finite element method, and the reliability of the system is validated. Based on the system built, the sensitivity values of different material parameters combinations were analyzed. The results show that (i) the maximum cross-sectional deformation ratio decreases with the increase of Young’s module E and strain hardening exponent n, while the effects of strength coefficient K, initial yield stress σS, and thickness anisotropy exponent γ on cross-sectional deformation are opposite to those of E and n, (ii) the groups which contain E and γ simultaneously show greater sensitivity and the effect of group only including E and γ on cross-sectional deformation is the most remarkable, while the most insensitive group in different combinations contains K, and (iii) mostly, the sensitivity values of coupling groups to cross-sectional deformation are larger than those of one-parameter groups.