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Materials Science and Engineering
Department of Mechanical and Materials Engineering: Faculty Publications
- Keyword
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- Finite element analysis (2)
- Artery (1)
- Blast wave (1)
- Crack propagation (1)
- Damage (1)
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- Dental nanocomposites (1)
- Discontinuous reinforcement (1)
- Doping (1)
- Dynamic fracture (1)
- Fiber-reinforced composites (1)
- Flow simulator (1)
- Gas emboli (1)
- Interface/interphase (1)
- Interphase (1)
- Isothermal (1)
- Layered structures (1)
- Low temperature (1)
- Mechanical properties (1)
- Mechanical testing (1)
- Micro-mechanics (1)
- Microstructures (1)
- PMMA (1)
- Peridynamics (1)
- Perovskite solar cells (1)
- Poly(methyl methacrylate) (1)
- Representative volume element (1)
- Saw-tooth (1)
- Sensitivity (1)
- Shear (1)
- Shear stress (1)
Articles 1 - 9 of 9
Full-Text Articles in Engineering
Negahban Group Report: Saw-Tooth Shear Response Of Aged Poly(Methyl Methacrylate) (Pmma), Mehrdad Negahban
Negahban Group Report: Saw-Tooth Shear Response Of Aged Poly(Methyl Methacrylate) (Pmma), Mehrdad Negahban
Department of Mechanical and Materials Engineering: Faculty Publications
Results for isothermal saw-tooth shear loading experiments conducted on annealed and oven-cooled poly(methyl methacrylate) (PMMA) at temperatures between 50oC and 140oC. The experiments were conducted 1996.
Low Temperature Solution-Processed Sb:Sno2 Nanocrystals For Efficient Planar Perovskite Solar Cells, Yang Bai, Yanjun Fang, Yehao Deng, Qi Wang, Jingjing Zhao, Xiaopeng Zheng, Yang Zhang, Jinsong Huang
Low Temperature Solution-Processed Sb:Sno2 Nanocrystals For Efficient Planar Perovskite Solar Cells, Yang Bai, Yanjun Fang, Yehao Deng, Qi Wang, Jingjing Zhao, Xiaopeng Zheng, Yang Zhang, Jinsong Huang
Department of Mechanical and Materials Engineering: Faculty Publications
Inorganic metal oxide electron-transport layers (ETLs) have the potential to yield perovskite solar cells with improved stability, but generally need high temperature to form conductive and defect-less forms, which is not compatible with the fabrication of flexible and tandem solar cells. Here, we demonstrate a facile strategy for developing efficient inorganic ETLs by doping SnO2 nanocrystals (NCs) with a small amount of Sb using a low-temperature solution-processed method. The electrical conductivity was remarkably enhanced by Sb-doping, which increased the carrier concentration in Sb:SnO2 NCs. Moreover, the upward shift of the Fermi level owing to doping results in improved …
Effect Of Er Doping On The Structural And Magnetic Properties Of Cobalt-Ferrite, Sateesh Prathapani, M. Vinitha, Tanjore V. Jayaraman, D. Das
Effect Of Er Doping On The Structural And Magnetic Properties Of Cobalt-Ferrite, Sateesh Prathapani, M. Vinitha, Tanjore V. Jayaraman, D. Das
Department of Mechanical and Materials Engineering: Faculty Publications
Nanocrystalline particulates of Er doped cobalt-ferrites CoFe(2–x)ErxO4 (0 ≤ x ≤ 0.04), were synthesized, using sol-gel assisted autocombustion method. Co-, Fe-, and Er- nitrates were the oxidizers, and malic acid served as a fuel and chelating agent. Calcination (400–600 °C for 4h) of the precursor powders was followed by sintering (1000 °C for 4 h) and structural and magnetic characterization. X-ray diffraction confirmed the formation of single phase of spinel for the compositions x = 0, 0.01, and 0.02; and for higher compositions an additional orthoferrite phase formed along with the spinel phase. …
Experimental Assessment Of The Impact Of Asymptomatic Gas Emboli On The Vessel Wall, Linxia Gu, Eric L. Cutler
Experimental Assessment Of The Impact Of Asymptomatic Gas Emboli On The Vessel Wall, Linxia Gu, Eric L. Cutler
Department of Mechanical and Materials Engineering: Faculty Publications
Quantitative evaluation of shear stress in the vessel wall due to the presence of asymptomatic gas emboli is lacking. The goal of this work was to assess the impact of chronic asymptomatic gas emboli on the risk of atherosclerosis through a custom-built cardiovascular flow simulator. Gas bubbles were created by forced air from a syringe pump. The influences of embolism injection rate, pulse rate, and time-averaged flow rate on the wall mean shear stress were investigated at resting and elevated heart rate conditions. The recorded pressure and volumetric flow rate from 24 experimental settings with four repetitions each were used …
High-Stress Shear-Induced Crystallization In Isotactic Polypropylene And Propylene/Ethylene Random Copolymers, Zhe Ma, Lucia Fernandez-Ballester, Dario Cavallo, Tim Gough, Gerrit W. M. Peters
High-Stress Shear-Induced Crystallization In Isotactic Polypropylene And Propylene/Ethylene Random Copolymers, Zhe Ma, Lucia Fernandez-Ballester, Dario Cavallo, Tim Gough, Gerrit W. M. Peters
Department of Mechanical and Materials Engineering: Faculty Publications
Crystallization of an isotactic polypropylene (iPP) homopolymer and two propylene/ethylene random copolymers (RACO), induced by high-stress shear, was studied using in situ synchrotron wide-angle X-ray diffraction (WAXD) at 137 °C. The “depth sectioning” method (Fernandez-Ballester, Journal of Rheology 53:5 (2009), pp. 1229−1254) was applied in order to isolate the contributions of different layers in the stress gradient direction and to relate specific structural evolution to the corresponding local stress. This approach gives quantitative results in terms of the specific length of fibrillar nuclei as a function of the applied stress. As expected, crystallization becomes faster with increasing stress—from the inner …
Prediction Of The Thermomechanical Behavior Of Particle-Reinforced Metal Matrix Composites, Yi Hua, Linxia Gu
Prediction Of The Thermomechanical Behavior Of Particle-Reinforced Metal Matrix Composites, Yi Hua, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
The objective of this paper was to predict the thermomechanical behavior of 2080 aluminum alloy reinforced with SiC particles using the Mori–Tanaka theory combined with the finite element method. The influences of particle volume fraction, stiffness, aspect ratio and orientation were examined in terms of effective Young’s modulus, Poisson’s ratio and coefficient of thermal expansion (CTE) of the composite. The microstructure induced local stress and strain field was obtained through the numerical models of the representative volume element. Results suggested that particle volume fraction had significant impact on the effective Young’s modulus, Poisson’s ratio and CTE of the composite. Stiffer …
Micromechanical Analysis Of Nanoparticle-Reinforced Dental Composites, Yi Hua, Linxia Gu, Hidehiko Watanabe
Micromechanical Analysis Of Nanoparticle-Reinforced Dental Composites, Yi Hua, Linxia Gu, Hidehiko Watanabe
Department of Mechanical and Materials Engineering: Faculty Publications
The mechanical behavior of TiO2 nanoparticle-reinforced resin-based dental composites was characterized in this work using a three-dimensional nanoscale representative volume element. The impacts of nanoparticle volume fraction, aspect ratio, stiffness, and interphase zone between the resin matrix and nanoparticle on the bulk properties of the composite were characterized. Results clearly demonstrated the mechanical advantage of nanocomposites in comparison to microfiber-reinforced composites. The bulk response of the nanocomposite could be further enhanced with the increased nanoparticle volume fraction, or aspect ratio, while the influence of nanoparticle stiffness was minimal. The effective Young’s modulus and yield strength of the composite was …
The Influence Of Heterogeneous Meninges On The Brain Mechanics Under Primary Blast Loading, Linxia Gu, Mehdi S. Chafi, Shailesh Ganpule, Namas Chandra
The Influence Of Heterogeneous Meninges On The Brain Mechanics Under Primary Blast Loading, Linxia Gu, Mehdi S. Chafi, Shailesh Ganpule, Namas Chandra
Department of Mechanical and Materials Engineering: Faculty Publications
In the modeling of brain mechanics subjected to primary blast waves, there is currently no consensus on how many biological components to be used in the brain–meninges–skull complex, and what type of constitutive models to be adopted. The objective of this study is to determine the role of layered meninges in damping the dynamic response of the brain under primary blast loadings. A composite structures composed of eight solid relevant layers (including the pia, cerebrospinal fluid (CSF), dura maters) with different mechanical properties are constructed to mimic the heterogeneous human head. A hyper-viscoelastic material model is developed to better represent …
Peridynamic Model For Dynamic Fracture In Unidirectional Fiber-Reinforced Composites, Wenke Hu, Youn Doh Ha, Florin Bobaru
Peridynamic Model For Dynamic Fracture In Unidirectional Fiber-Reinforced Composites, Wenke Hu, Youn Doh Ha, Florin Bobaru
Department of Mechanical and Materials Engineering: Faculty Publications
We propose a computational method for a homogenized peridynamics description of fiber-reinforced composites and we use it to simulate dynamic brittle fracture and damage in these materials. With this model we analyze the dynamic effects induced by different types of dynamic loading on the fracture and damage behavior of unidirectional fiber-reinforced composites. In contrast to the results expected from quasi-static loading, the simulations show that dynamic conditions can lead to co-existence of and transitions between fracture modes; matrix shattering can happen before a splitting crack propagates. We observe matrix–fiber splitting fracture, matrix cracking, and crack migration in the matrix, including …