scholarly journals FURTHER RESULTS ON THE INITIATION AND GROWTH OF ADIABATIC SHEAR BANDS AT HIGH STRAIN RATES

1985 ◽  
Vol 46 (C5) ◽  
pp. C5-323-C5-330 ◽  
Author(s):  
T. W. Wright ◽  
R. C. Batra
Keyword(s):  
High Strain ◽  
Shear Bands ◽  
Adiabatic Shear ◽  
Strain Rates ◽  
Adiabatic Shear Bands ◽  
High Strain Rates

Inspection of Adiabatic Shear Bands in High Manganese TRIP Steels

2013 ◽  
Vol 753 ◽  
pp. 72-75 ◽  
Author(s):  
Hui Zhen Wang ◽  
Xiu Rong Sun ◽  
Ping Yang ◽  
Wei Min Mao
Keyword(s):  
Shear Failure ◽  
High Strain ◽  
Shear Bands ◽  
Adiabatic Shear ◽  
Strain Rates ◽  
Trip Effect ◽  
Adiabatic Shear Bands ◽  
High Manganese ◽  
High Strain Rates ◽  
Trip Steels

Adiabatic shear bands (ASBs) develop generally during high strain rates. This paper investigates the transformation induced plasticity (TRIP) effect during ASBs formation at high strain rates in high manganese TRIP steels containing initial austenite and ferrite by EBSD technique. Results show that TRIP effect takes place mainly before the formation of ASBs. After ASBs formation, TRIP effect is strongly restricted by the size effect, the increase of stacking fault energy (SFE) and even inverse martensitic transformation due to the rise of temperature. The TRIP effect before ASBs formation contributes to the resistance of adiabatic shear failure. Dynamic recrystallization driven by subgrains rotation occurs within ASBs, and ultrafine grains often show strong shear textures with twin relationship owing to slip mechanism.

Deformation Behavior of Ti-6Al-4V-0.1B Alloy Loaded under High Strain Rates

2016 ◽  
Vol 849 ◽  
pp. 266-270 ◽  
Author(s):  
Yang Yu ◽  
Qi Gao ◽  
Xun Jun Mi ◽  
Song Xiao Hui ◽  
Wen Jun Ye
Keyword(s):  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Shear Bands ◽  
Adiabatic Shear ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
High Strain Rates ◽  
The Matrix ◽  
Split Hopkinson ◽  
Pressure Bar

Deformation and fracture behaviors of Ti-6Al-4V-0.1B alloy with Widmanstätten, equiaxed and bimodal microstructures were investigated by Split Hopkinson Pressure Bar (SHPB) under high strain rates of 2100-3200 s-1. The results showed that the equiaxed and bimodal structures had a higher bearing capacity at high strain rates than that of the Widmanstätten structure. With the same microstructure, the increase of strain rate gave rise to an improved uniform plastic deformation. According to an observation on the deformed microstructure, it was found that adiabatic shear behavior was the main reason for failure and fracture of the alloy. The formation and propagation of adiabatic shear bands (ASBs) was the precursor for the failure and fracture of the material. Cavities at the interface between TiB phase and the matrix readily formed due to the uncoordinated deformation, which are not the dominate reason for the failure and fracture.

Modelling of Formation of Adiabatic Shear Bands

2014 ◽  
Vol 566 ◽  
pp. 92-96
Author(s):  
Nabil Bassim ◽  
Jeffrey Delorme
Keyword(s):  
Strain Hardening ◽  
Dimensional Analysis ◽  
Shear Bands ◽  
Hopkinson Bar ◽  
Thermal Softening ◽  
Adiabatic Shear ◽  
Large Strains ◽  
Strain Rates ◽  
Adiabatic Shear Bands ◽  
Impact Compression

Adiabatic shear bands are microstructural features that appear when metals, and some non-metals are subjected to impact loading at strain rates in excess of 103 s-1 and large strains. The formation of these bands is generally attributed to several competing mechanisms, among them is an initial strain hardening followed by adiabatic thermal softening that may lead to crack initiation within the bands. The authors have developed a model for formation of adiabatic shear bands in metallic materials as they are formed during testing using a torsional Hopkinson Bar. The model relies on a one dimensional analysis which predicts accurately the two steps of forming adiabatic shear bands in terms of strain hardening followed by thermal softening. In this current research, the model is extended to a two-dimensional analysis which would be suitable for application in either a two bar compression Split Hopkinson Bar or in a direct impact compression system developed by the author (Nabil Bassim) to produce high strain rates and large strains. The algorithm relies on applying the concept of dynamic recrystallization in order to determine the onset or initiation of the adiabatic shear bands.

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