In situobservation of size-scale effects on the mechanical properties of ZnO nanowires

2011 ◽  
Vol 22 (26) ◽  
pp. 265712 ◽  
Author(s):  
A Asthana ◽  
K Momeni ◽  
A Prasad ◽  
Y K Yap ◽  
R S Yassar
Solids ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 50-59
Author(s):  
Wojciech Gilewski ◽  
Anna Al Sabouni-Zawadzka

This paper is dedicated to the extended solid (continuum) model of tensegrity structures or lattices. Tensegrity is defined as a pin-joined truss structure with an infinitesimal mechanism stabilized by a set of self-equilibrated normal forces. The proposed model is inspired by the continuum model that matches the first gradient theory of elasticity. The extension leads to the second- or higher-order gradient formulation. General description is supplemented with examples in 2D and 3D spaces. A detailed form of material coefficients related to the first and second deformation gradients is presented. Substitute mechanical properties of the lattice are dependent on the cable-to-strut stiffness ratio and self-stress. Scale effect as well as coupling of the first and second gradient terms are identified. The extended solid model can be used for the evaluation of unusual mechanical properties of tensegrity lattices.


Author(s):  
Kasra Momeni

A multiscale approach is pursued for modeling the size-scale effect on generated electric potential by nanocomposite electrical generators of ZnO nanowires. A core-surface model is used for capturing the effect of size-scale on elastic modulus of ZnO NWs. In this model, a surface with different elastic modulus as of the core of NW was considered. Using linear elasticity and axisymmetric configuration of this problem, closed form governing equations are derived in cylindrical coordinate system. Parametric studied are performed for sample cases to demonstrate application of the developed model. It is shown that ZnO nanowires with larger aspect ratio and smaller diameters have higher performance and can produce higher electric potential.


1973 ◽  
Vol 99 (3) ◽  
pp. 417-430
Author(s):  
J. Paul Tullis ◽  
Rangachari Govindarajan
Keyword(s):  

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Aditi Roy ◽  
James Mead ◽  
Shiliang Wang ◽  
Han Huang

2007 ◽  
Vol 134 (1) ◽  
pp. 169-176 ◽  
Author(s):  
A.V. Desai ◽  
M.A. Haque

Author(s):  
Tandra Bagchi ◽  
Zahid Hossain ◽  
Mohammed Ziaur Rahaman ◽  
Gaylon Baumgardner

Multi-scale evaluation of the rheological and mechanical properties of asphalt binder has substantial importance in understanding the binder’s micro- and macro-scale properties. This study compares the macro- and micro-scale mechanistic properties of asphalt binders. Test samples used in this study include performance grade binders (PG 64-22) from two different sources along with their modified counterparts. The modifiers include polyphosphoric acid (PPA), styrene-butadiene-styrene (SBS), a combination of SBS and PPA, and reclaimed asphalt pavement. To achieve the goal of this study, atomic force microscope technology was utilized to estimate the asphalt binder’s micro-mechanical properties (e.g., Derjaguin, Muller, Toropov modulus and deformation). On the other hand, data on the macro-scale properties—such as rutting factor (G*/sinδ), consistency and penetration—of the selected binders were analyzed and compared with the aforementioned micro-level properties. The comparative analyses indicated that the micro-mechanical properties of asphalt binders followed a linear trend with the macro-scale properties. The findings of this study are expected to help researchers and pavement professionals in modeling asphalt materials when multi-scale effects are deemed to be necessary.


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