scholarly journals Capturing Rate-Dependent Shear Localization Using a Traction Balance Mixed Zone Closure Model and a Shear Band Insertion Mechanism in ALE3D

2018 ◽  
Author(s):  
J D Margraf
Keyword(s):  
Shear Band ◽  
Shear Localization ◽  
Closure Model ◽  
Mixed Zone ◽  
Rate Dependent ◽  
Insertion Mechanism

Quantitative Study of Shear Localization in Chip Formation while Machining Ti-6Al-4V

2009 ◽  
Vol 407-408 ◽  
pp. 412-415
Author(s):  
Dong Liu ◽  
Wu Yi Chen ◽  
Hong Hai Xu ◽  
Xue Ke Luo ◽  
Hui Liang
Keyword(s):  
Shear Band ◽  
Shear Flow ◽  
Quantitative Study ◽  
Cutting Speed ◽  
Optical Microscope ◽  
Shear Localization ◽  
Adiabatic Shear ◽  
Plastic Shear ◽  
Orthogonal Machining ◽  
Cutting Speeds

The formation of shear localized chips in orthogonal machining of Ti-6Al-4V was investigated. The chips in different cutting velocities were collected and the structure of the adiabatic shear localization was examined by optical microscope and SEM after polishing and eroding. The serrated coefficient, serrated frequency and fibred coefficient were proposed in this paper to characterize the degree of serration and plastic shear flow of the chip quantitatively. Experimental results show that the width of the shear band decreased and the fibred coefficient of the shear band increased as cutting speed increased. The serrated and frequency, the serrated coefficient increased with the increase of cutting speed in the experimental range of cutting speeds.

Analytical Modeling of Shear Localization in Orthogonal Cutting Processes

2021 ◽  
pp. 1-45
Author(s):  
Mohammadreza Fazlali ◽  
Mauricio Ponga ◽  
Xiaoliang Jin
Keyword(s):  
Shear Band ◽  
Orthogonal Cutting ◽  
Shear Bands ◽  
Chip Morphology ◽  
High Strength ◽  
Shear Localization ◽  
Shear Band Formation ◽  
Workpiece Material ◽  
Band Formation ◽  
Cutting Processes

Abstract This paper presents an analytical thermo-mechanical model of shear localization and shear band formation in orthogonal cutting of high-strength metallic alloys. The deformation process of the workpiece material includes three stages: homogeneous deformation, shear localization, and chip segmentation. A boundary layer analysis is used to analytically predict the temperature, stress, and strain rate variations in the primary shear zone associated with the shear localization. The predictions of shear band spacing and width from the proposed model are verified by experimental characterization of the chip morphology. The rolling of shear bands on the tool rake face is discussed from the experimental observations. The cutting tool temperature, which is influenced by the heat generated during the shear band formation, is simulated and compared with the finite element simulations. The proposed analytical model reveals the fundamental mechanism of the complete shear localization process in orthogonal cutting, and predicts the stress and temperature variations with high computational efficiency.

Analysis of Shear Band Development in a Viscoplastic Double Slip, Single Crystal in Tension

1995 ◽  
Vol 62 (4) ◽  
pp. 827-833 ◽  
Author(s):  
S. Yang ◽  
C. Rey
Keyword(s):  
Shear Band ◽  
Single Crystal ◽  
Shear Banding ◽  
Rate Sensitivity ◽  
Shear Localization ◽  
Rigid Plastic ◽  
Band Formation ◽  
Linearized Stability ◽  
Slow Progression ◽  
Crystal Model

Using an idealized planar single crystal model undergoing symmetrical double slip in tension, the effect of rate sensitivity on shear band initiation and on shear band development is analysed. The behavior of the crystal is assumed to be rigid-viscoplastic. By analysing the kinematics and statics of shear banding, the deformation modes involving shear banding pattern are formulated. By a linearized stability analysis, the critical condition for shear band initiation is obtained. To study shear band development, the formulated constitutive equations are numerically solved, and the maximum value of the localized shear is predicted. The results show three different stages of shear band development. The first corresponds to a slow progression of shear localization in the band, the second to a rapid shear localization accompanied with an unloading of surrounding material, and the third to a resumption of deformation in the surrounding material and to a progressive saturation of the shear band. All three stages depend strongly on rate sensitivity, especially the first stage which does not exist in the rigid-plastic case. Even very small rate sensitivity can delay significantly or even preclude the shear band formation. Finally a discussion of the results illustrates how a macroscopic shear band forms and propagates.

scholarly journals Rate-dependent shear-band initiation in a metallic glass

2015 ◽  
Vol 106 (17) ◽  
pp. 171907 ◽  
Author(s):  
D. Tönnies ◽  
K. Samwer ◽  
P. M. Derlet ◽  
C. A. Volkert ◽  
R. Maaß
Keyword(s):  
Shear Band ◽  
Metallic Glass ◽  
Rate Dependent
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