Statistics of Stress Drop and Multifractal Analysis of Portevin-Le Chatelier Effect in Al5052

Through the Al5052 uniaxial tensile test, serrated yield effect (PLC effect) was observed at the selected different strain rates. In this paper, the PLC effect of Al5052 was analyzed though stress drop statistics and multifractal analysis. The results of PLC effect under different strain rates were analyzed and discussed. With the increase of the strain rate, the distribution of stress drop statistical transits from peak shape to monotonically decreasing distribution, and the broadband of multifractal spectrum increases. This shows that the type of dynamics has changed from chaos model to the self-organized critical mode. With strain rate increasing, the uniformity of stress burst rate is worsen, whose reason can be illustrated through the relationship between re-loading time and the characteristics release time of internal stress. In addition, an asymmetric index has been introduced to illustrate the enrichment or loss on the intensity of stress burst rate under different strain rates.