Tensile behavior of tailor rolled blanks: mathematical modeling and design optimization

Abstract

In this study, a mathematical model considering geometrical characteristics of thickness transition zone (TTZ) has been developed to predict tensile behavior of tailor rolled blanks (TRBs). To prove the accuracy of the presented model, uniaxial tension tests were carried out using tensile specimens fabricated from TRBs with different TTZ geometries (thickness ratio varies between 0.47 and 0.89 and length of TTZ changes from 58 to 110 mm). The error analysis showed that the predicted results correlate well with the ones obtained from uniaxial tension tests. In addition, utilizing the presented model, a new mathematical relation was proposed to obtain the optimized design for TTZ at each thickness ratio. Accordingly, for thickness ratios below 0.5, it is anticipated that total percent elongation of TRBs increases up to a maximum point with increasing effective length ratio (ELR), characterized by a critical ELR parameter. However, for thickness ratios above 0.5, the elongation-ELR curves may display a full ascending trend with no peak point within 0 < ELR ≤ 0.5. The reasons behind these variations were fully discussed.