Mixed mode (I and II) crack tip fields in bulk metallic glasses

On the mechanism and the length scales involved in the ductile fracture of a bulk metallic glass

“…It should be noted that the orientation of the dominant shear band and the crack path is consistent with that reported in the pure mode II experiments of Flores and Dauskardt [34]. It is also close to the location of peak in maximum principal logarithmic plastic strain, ln k p 1 , for the mode II case observed in the work of Tandaiya et al [19]. From Fig.…”

“…The mechanical properties of relevance of this material are [13]: Young's modulus E = 97 GPa, Poisson's ratio m = 0.36, compressive yield strength r c y ¼ 1:82 GPa, tensile yield strength r t y ¼ 1:61 GPa. In the earlier paper [19], we had employed asymmetric and symmetric four-point-bend notched specimens to conduct mixed-mode (I and II) and pure mode I fracture tests, respectively, such that different values of the near-tip plastic mode-mixity parameter, M p , are obtained. M p is defined as [22] M p ¼ lim…”

“…Recently, we have conducted experimental and numerical studies on mixed-mode fracture in a Zr-based BMG with the primary purposes of examining the nature of crack tip fields in the mixed-mode specimens within a plane strain, small scale yielding (SSY) framework and to understand the influence of the internal friction parameter and mode-mixity on the plastic zones and stress and plastic strain distributions near the crack tip [19,20]. Possible trends in fracture toughness versus mode-mixity were investigated and some experimental results were presented to validate the SSY analysis.…”

The ductile to brittle transition behavior in a Zr-based bulk metallic glass

“…Some BMGs exhibit good fracture toughness while some exhibit poor fracture toughness. The former is called ductile BMG and the latter is the brittle one, which has been mentioned by Ramamurty group in their recent papers [56][57][58]. Here, DBT of BMGs was defined as the transition of microscopic fracture feature and macroscopic fracture mode.…”

Dynamic fragmentation induced by network-like shear bands in a Zr-based bulk metallic glass

“…This unique combination may lead to an abnormal mechanism of fragmentation. According to recent studies by Tandaiya et al [18,19], crack initiates and then stably grows inside one dominant shear band in bending tests of BMGs with a notch, which shows that shear bands are precursors of cracks. Fracture of Zr-based BMGs into a few fragments has been discovered in split-Hopkinson pressure bar [20,21] and anvil-onrod impact tests [12,22].…”