The post Hasnain Sajid’s work appears in J Phys Chem C! appeared first on Nanomechanics Research Group.

Congratulations to Arnav Rana, who successfully defended his PhD thesis today.  Arnav’s work, entitled “Studies of Anisotropic Ductile Fracture Behaviour in Pipeline Steels,” is an important and practical extension of fracture models for anisotropic materials.  The work lead to three publications in excellent journals.  Great work, Arnav

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Arnav has made a nice contribution to the literature on J-Q theory, quantifying the limits of applicability of the theory in ductile fracture students, especially when crack planes are misaligned with respect to the material coordinate system. This highlights the importance of the consideration of plastic anisotropy when performing constraint-based fracture mechanics analyses. 

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Alireza’s second paper with the group, “Prediction of PAN oxidation in a gas turbine bearing chamber using coupled chemical kinetics and CFD simulation of lubricant flow” has been accepted to Thermal Science and Engineering Progress (.  This work is an important building block in our efforts to create a predictive model of antioxidant consumption in lubricant oils.

Congratulations Alireza!

The post Alireza Rezvanpour paper accepted to Thermal Science and Engineering Progress appeared first on Nanomechanics Research Group.

, we proposed scaling analysis as a simple approach to replace experimental measurements to validate CFD results. In fact, we used scaling analysis to validate the simulation results due to insufficient experimental results.

The journal bearing housing of a gas turbine engine was studied in this work. The authors considered the influences of the revolution speed of the rotor on the velocity, pressure and temperature distribution of the bulk oil at fixed inlet velocity and inlet temperature. First of all, we performed a CFD simulation on the fluid flow and heat transfer in the bulk oil of the bearing housing using COMSOL 6. Then, MATLAB R2022a was used to model scaling analysis results. Finally, the CFD simulation results were compared with the final equation obtained by the scaling analysis.

Overall, we found that the CFD simulation developed in this work is physically valid. We showed an agreement between the simulation results and the governing equations of the system, especially at higher rotational speeds.

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Rafaela’s second paper, “Microstructural evidence of the toughening mechanisms of polyurethane reinforced with halloysite nanotubes under high strain-rate tensile loading,” has been accepted to Scientific Reports ().  Rafaela has made ground-breaking contributions to the synthesis and understanding of transparent nanocomposites for high strain-rate applications.

The post Rafaela Aguiar’s work accepted to Scientific Reports appeared first on Nanomechanics Research Group.

, we computed the spall strength of polyurethane samples by following two methods:

(1) The indirect method (from the free surface velocity history, which is commonly used in experiments)

(2) A direct method (from the atomic stresses in the spall region, which is possible only in MD)

The results reveal that the tensile strength computed from the indirect method is consistently smaller than the value obtained from the direct method. Moreover, the strength computed from the indirect method shows an excellent agreement with the fracture nucleation stress.  

The MD model we used in this paper is

The post Our article on the MD simulations of spallation in polymers appears in the Journal of Applied Mechanics appeared first on Nanomechanics Research Group.

we conducted MD simulations to demonstrate that the ballistic limit velocity and the specific penetration energy of SiC/polyurea multilayers are significantly higher than the experimentally measured values of other protective materials.

Moreover, we demonstrated that the specific penetration energy of a nanoscale target with a given material composition can be remarkably improved (over 75%) by optimizing the individual layer thickness and their arrangement within the target.

Our results reveal a potential bottom-up design pathway for developing superior protective materials for extreme engineering applications.

A video abstract of the article . Molecular dynamics (LAMMPS) and density functional theory (VASP) models used to compute the force-field parameters to describe the nonbonded interactions between silicon carbide and polyurea .

The post Our work on the ballistic performance of SiC/polyurea nanostructures is published in Extreme Mechanics Letters appeared first on Nanomechanics Research Group.

Post-doctoral fellow, Dr. Alireza Rezvanpour (PhD from the Chemical & Biomolecular Engineering Department at the National University of Singapore) joins the group as part of the team investigating the characterization and modeling of the degradation of anti-oxidants in lubricating oils.  Welcome, Alireza!

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Post-doctoral fellow, Dr. Timothy Mack (PhD in Chemistry, McGill, 2019) joins the group as part of the team investigating the characterization and modeling of the degradation of anti-oxidants in lubricating oils.  Welcome, Tim!

The post Welcome Timothy Mack appeared first on Nanomechanics Research Group.