scholarly journals Critique of materials‐based models of ductile machining in brittle solids

2020 ◽  
Vol 103 (11) ◽  
pp. 6096-6100 ◽  
Author(s):  
Han Huang ◽  
Brian R. Lawn ◽  
Robert F. Cook ◽  
David B. Marshall
Keyword(s):  
Brittle Solids ◽  
Ductile Machining

On impact upon brittle solids

2000 ◽  
Vol 10 (PR9) ◽  
pp. Pr9-281-Pr9-286 ◽  
Author(s):  
N. K. Bourne ◽  
J. C.F. Millett
Keyword(s):  
Brittle Solids

scholarly journals Simulation of the ductile machining mode of silicon

2021 ◽  
Author(s):  
Hagen Klippel ◽  
Stefan Süssmaier ◽  
Matthias Röthlin ◽  
Mohamadreza Afrasiabi ◽  
Uygar Pala ◽  
...  
Keyword(s):  
Brittle Material ◽  
Material Removal ◽  
Machining Process ◽  
Ductile Material ◽  
Diamond Wire ◽  
Ductile Machining ◽  
Mesh Free ◽  
Diamond Wire Sawing ◽  
Material Removal Mode ◽  
Brittle Material Removal

AbstractDiamond wire sawing has been developed to reduce the cutting loss when cutting silicon wafers from ingots. The surface of silicon solar cells must be flawless in order to achieve the highest possible efficiency. However, the surface is damaged during sawing. The extent of the damage depends primarily on the material removal mode. Under certain conditions, the generally brittle material can be machined in ductile mode, whereby considerably fewer cracks occur in the surface than with brittle material removal. In the presented paper, a numerical model is developed in order to support the optimisation of the machining process regarding the transition between ductile and brittle material removal. The simulations are performed with an GPU-accelerated in-house developed code using mesh-free methods which easily handle large deformations while classic methods like FEM would require intensive remeshing. The Johnson-Cook flow stress model is implemented and used to evaluate the applicability of a model for ductile material behaviour in the transition zone between ductile and brittle removal mode. The simulation results are compared with results obtained from single grain scratch experiments using a real, non-idealised grain geometry as present in the diamond wire sawing process.

scholarly journals Variable-order fracture mechanics and its application to dynamic fracture

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Sansit Patnaik ◽  
Fabio Semperlotti
Keyword(s):  
Dynamic Fracture ◽  
Crack Surface ◽  
A Priori ◽  
Computational Cost ◽  
Dynamic Crack Propagation ◽  
Benchmark Problems ◽  
Variable Order ◽  
Dynamic Crack ◽  
Brittle Solids ◽  
Complex Crack

AbstractThis study presents the formulation, the numerical solution, and the validation of a theoretical framework based on the concept of variable-order mechanics and capable of modeling dynamic fracture in brittle and quasi-brittle solids. More specifically, the reformulation of the elastodynamic problem via variable and fractional-order operators enables a unique and extremely powerful approach to model nucleation and propagation of cracks in solids under dynamic loading. The resulting dynamic fracture formulation is fully evolutionary, hence enabling the analysis of complex crack patterns without requiring any a priori assumption on the damage location and the growth path, and without using any algorithm to numerically track the evolving crack surface. The evolutionary nature of the variable-order formalism also prevents the need for additional partial differential equations to predict the evolution of the damage field, hence suggesting a conspicuous reduction in complexity and computational cost. Remarkably, the variable-order formulation is naturally capable of capturing extremely detailed features characteristic of dynamic crack propagation such as crack surface roughening as well as single and multiple branching. The accuracy and robustness of the proposed variable-order formulation are validated by comparing the results of direct numerical simulations with experimental data of typical benchmark problems available in the literature.

An Overall Approach for Microcrack and Inhomogeneity Toughening in Brittle Solids

1999 ◽  
Vol 15 (2) ◽  
pp. 57-68
Author(s):  
Huang Hsing Pan
Keyword(s):  
Poisson Ratio ◽  
Crack Density ◽  
Mean Field ◽  
Analytic Form ◽  
Density Parameter ◽  
Brittle Solids ◽  
The Matrix ◽  
Microcrack Toughening ◽  
Average Quantity ◽  
The Mean

ABSTRACTBased on the weight function theory and Hutchinson's technique, the analytic form of the toughness change near a crack-tip is derived. The inhomogeneity toughening is treated as an average quantity calculated from the mean-field approach. The solutions are suitable for the composite materials with moderate concentration as compared with Hutchinson's lowest order formula. The composite has the more toughened property if the matrix owns the higher value of the Poisson ratio. The composite with thin-disc inclusions obtains the highest toughening and that with spheres always provides the least effective one. For the microcrack toughening, the variations of the crack shape do not significantly affect the toughness change if the Budiansky and O'Connell crack density parameter is used. The explicit forms for three types of the void toughening and two types of the microcrack toughening are also shown.

scholarly journals Shock-induced structural instability and dynamic strength of brittle solids

2016 ◽  
Vol 2 ◽  
pp. 477-484 ◽  
Author(s):  
Yurii Meshcheryakov ◽  
Alexandre Divakov ◽  
Natali Zhigacheva ◽  
Grigorii Konovalov
Keyword(s):  
Dynamic Strength ◽  
Structural Instability ◽  
Brittle Solids

scholarly journals Dynamic Mixed Mode I-II Crack Kinking Under Oblique Stress Wave Loading in Brittle Solids

1990 ◽  
Vol 57 (1) ◽  
pp. 117-127 ◽  
Author(s):  
Chien-Ching Ma
Keyword(s):  
Stress Intensity ◽  
Stress Wave ◽  
Stress Intensity Factors ◽  
Crack Tip ◽  
Elastic Solid ◽  
Perturbation Parameter ◽  
Intensity Factors ◽  
Linear Superposition ◽  
Dynamic Stress Intensity Factors ◽  
Brittle Solids

The dynamic stress intensity factors of an initially stationary semi-infinite crack in an unbounded linear elastic solid which kinks at some time tf after the arrival of a stress wave is obtained as a function of kinking crack tip velocity v, kinking angle δ, incident stress wave angle α, time t, and the delay time tf. A perturbation method, using the kinking angle δ as the perturbation parameter, is used. The method relies on solving simple problems which can be used with linear superposition to solve the problem of a kinked crack. The solutions can be compared with numerical results and other approximate results for the case of tf = 0 and give excellent agreement for a large range of kinking angles. The elastodynamic stress intensity factors of the kinking crack tip are used to compute the corresponding fluxes of energy into the propagating crack-tip, and these results are discussed in terms of an assumed fracture criterion.

Dynamic crack branching in brittle solids

1985 ◽  
Vol 27 (3-4) ◽  
pp. 203-213 ◽  
Author(s):  
J. P. Dempsey ◽  
P. Burgers
Keyword(s):  
Crack Branching ◽  
Dynamic Crack ◽  
Brittle Solids

To the Theory of Formation of Large Cracks in Brittle Solids

2021 ◽  
Author(s):  
Yu. A. Khon ◽  
P. V. Makarov
Keyword(s):  
Brittle Solids
Sign in / Sign up

Export Citation Format

Share Document