An experimental study on spontaneous adiabatic shear band formation in electro-magnetically collapsing cylinders

Shear band patterning and post-critical behavior in AISI 4340 steel with different microstructure

“…Nevertheless, these models describe only qualitative results, and fail to recapture both length and spacing observed in experiments. Although results are in the same order of magnitude, they are off by a factor of 3-4 [21].…”

“…In this model, A , B , c , n , and m are model constants, έ p is the effective plastic strain, and έ ¿ is the normalized effective total strain-rate. The action of the explosive was modeled using a pressure boundary condition similar to [21,30] that collapses the central cavity in about 10 s. To capture damage, we used the approach presented in [54]:…”

“…The explosively-driven method was proposed by Nesterenko et al [4,[10][11][12][13][14][15][16] to investigate spontaneous shear instability, patterns of shear bands in solid and granular materials, and buckling of laminates (inert and reactive). It also was used by other researchers [17,18] and later modifications of this method using electromagnetic drive [19][20][21][22][23], Hopkinson bar [24], and gas gun [25]. Analytical approaches to describe the thickness and spacing of adiabatic shear bands have been developed starting with the paper by Grady and Kipp [26] and detailed explanations can be found in [2,[27][28][29].…”

“…Numerical calculations were used to study formation and evolution of ASB and their emerging self-organized pattern in the geometry corresponding to the TWC test in different materials such as Cu, Ti, and AISI 304L in [19][20][21][30][31][32][33]. The difference in these approaches lies in the failure criteria that give a positive feedback mechanism for the strain localization.…”

“…These authors invoked energy or strain criteria [21][22][23] weakening the material and resulting in nucleation of a shear band. In [22] authors connected rapid development of localization in Ti6Al4V to dynamic recrystallization and delay in shear localization in CP-Titanium and in MgAM50 to a significant twinning absent in Ti6Al4V.…”