Dynamic compression-shear response of brittle materials with specimen recovery

2000 ◽  
Vol 40 (3) ◽  
pp. 321-330 ◽  
Author(s):  
H. D. Espinosa ◽  
A. Patanella ◽  
Y. Xu
Keyword(s):  
Dynamic Compression ◽  
Brittle Materials ◽  
Shear Response ◽  
Specimen Recovery

Micromechanical Studies of Strain Rate Dependent Compressive Strength in Brittle Polycrystalline Materials

2019 ◽  
Vol 16 (04) ◽  
pp. 1844011
Author(s):  
Hao Jiang ◽  
Zongyue Fan ◽  
Jian Lu ◽  
Bo Li
Keyword(s):  
Finite Element ◽  
Energy Release Rate ◽  
Grain Boundaries ◽  
Energy Release ◽  
Release Rate ◽  
Dynamic Compression ◽  
Brittle Materials ◽  
Polycrystalline Materials ◽  
Critical Energy Release Rate ◽  
Rate Dependent

We propose a novel computational model for the high fidelity prediction of failure mechanisms in brittle polycrystalline materials. A three-dimensional finite element model of the polycrystalline structure is reconstructed to explicitly account for the micro-features such as grain sizes, grain orientations, and grain boundary misorientations. Grain boundaries are explicitly represented by a thin layer of elements with non-zero misorientation angles. In addition, the Eigen-fracture algorithm is employed to predict the crack nucleation and propagation in the grain structure. In the framework of variational fracture mechanics, an equivalent energy release rate is defined at each finite element to evaluate the local failure state by comparing to the critical energy release rate, which varies at the grain boundaries and the interior of grains. Moreover, constitutive models are considered as functions of the local microstructure features. As a result, a direct mesoscale simulation model is developed to resolve the anisotropic response, intergranular and transgranular fractures during the microstructure evolution of brittle materials under general loading conditions. A micromechanics-based interpretation for the rate dependent strength of brittle materials is derived and verified in examples of dynamic compression tests. In specific, the compressive dynamic response of hexagonal SiC with equiaxed grain structures is studied under different strain rates.

scholarly journals Modeling and Design of SHPB to Characterize Brittle Materials under Compression for High Strain Rates

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2191 ◽  
Author(s):  
Tomasz Jankowiak ◽  
Alexis Rusinek ◽  
George Z. Voyiadjis
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Brittle Materials ◽  
Material Strength ◽  
Strain Rates ◽  
Analytical Prediction ◽  
Hopkinson Pressure Bar ◽  
Finite Element Software ◽  
Pressure Bar

This paper presents an analytical prediction coupled with numerical simulations of a split Hopkinson pressure bar (SHPB) that could be used during further experiments to measure the dynamic compression strength of concrete. The current study combines experimental, modeling and numerical results, permitting an inverse method by which to validate measurements. An analytical prediction is conducted to determine the waves propagation present in SHPB using a one-dimensional theory and assuming a strain rate dependence of the material strength. This method can be used by designers of new SPHB experimental setups to predict compressive strength or strain rates reached during tests, or to check the consistencies of predicted results. Numerical simulation results obtained using LS-DYNA finite element software are also presented in this paper, and are used to compare the predictions with the analytical results. This work focuses on an SPHB setup that can accurately identify the strain rate sensitivities of concrete or brittle materials.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

Failure wave as resonance excitation of collective burst modes of defects in shocked brittle materials

2000 ◽  
Vol 10 (PR9) ◽  
pp. Pr9-811-Pr9-816 ◽  
Author(s):  
O. A. Plekhov ◽  
D. N. Eremeev ◽  
O. B. Naimark
Keyword(s):  
Brittle Materials ◽  
Resonance Excitation ◽  
Failure Wave

Atypical Femoral Fracture in McCune-Albright Syndrome

2020 ◽  
Vol 7 (3) ◽  
pp. 147-152
Author(s):  
Salman Ghaffari ◽  
◽  
Mehran Razavipour ◽  
Parastoo Mohammad Amini ◽  
◽  
...  
Keyword(s):  
Femoral Fracture ◽  
Dynamic Compression ◽  
Plate Fixation ◽  
Medullary Canal ◽  
Mccune Albright Syndrome ◽  
Café Au Lait Spots ◽  
History Of ◽  
Albright Syndrome ◽  
Mccune Albright

McCune-Albright Syndrome (MAS) is characterized by endocrinopathies, café-au-lait spots, and fibrous dysplasia. Bisphosphonates are the most prescribed treatment for reducing the pain but their long-term use has been associated with atypical fractures of cortical bones like femur in patients. We present a 23-year-old girl diagnosed with MAS. She had an atypical mid-shaft left femoral fracture that happened during simple walking. She also had a history of long-term use of alendronate. Because of the narrow medullary canal, we used 14 holes hybrid locking plate for the lateral aspect of the thigh to fix the fracture and 5 holes dynamic compression plate (instead of the intramedullary nail) in the anterior surface to double fix it, reducing the probability of device failure. With double plate fixation and discontinuation of alendronate, the complete union was achieved five months after surgery

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