Notch plasticity and fatigue modelling of AZ31B-H24 magnesium alloy sheet 2019-01-0530
Vehicle weight reduction through the use of components made of magnesium alloys is an effective way to reduce carbon dioxide emission and improve fuel economy. In the design of these components, which are mostly under cyclic loading, notches are inevitably present. In this study, surface strain distribution and crack initiation sites in the notch region of AZ31B-H24 Mg alloy specimens under uniaxial load are recorded via digital image correlation. Predicted strains from finite-element analysis using LS-DYNA material types 124 (MAT_PLASTICITY_COMPRESSION_TENSION) and 233 (MAT_CAZACU_BARLAT) are compared against experimental measurements during quasi-static and cyclic loadings. It is concluded that MAT_233, when calibrated using cyclic tensile and compressive stress-strain curves, is capable of predicting strain at the notch root. Differences in strain distribution and crack initiation sites are also found between the predicted and measured values, and some possible reasons are discussed.
Lin Feng Victor Qian, Ali A. Roostaei, Yibing Shi, Umesh Dighrasker, Mohammed Malik, Marie Mills, Yung-Li Lee, Grzegorz Glinka, Hamid Jahed
University of Waterloo, FCA US LLC, FCA Canada Inc