Micropolar theory from the viewpoint of mesoscopic and mixture theories

2017 ◽  
Vol 20 (3) ◽  
pp. 263-279 ◽  
Author(s):  
W. H. Müller ◽  
E. N. Vilchevskaya
Keyword(s):  
Micropolar Theory ◽  
Mixture Theories

scholarly journals Torsional Characteristics of Carbon Nanotubes: Micropolar Elasticity Models and Molecular Dynamics Simulation

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 453
Author(s):  
Razie Izadi ◽  
Meral Tuna ◽  
Patrizia Trovalusci ◽  
Esmaeal Ghavanloo
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Scale Effects ◽  
Couple Stress Theory ◽  
Dynamics Simulation ◽  
Local Theory ◽  
Beam Model ◽  
Specific Class ◽  
Micropolar Theory ◽  
Material Parameters

Efficient application of carbon nanotubes (CNTs) in nano-devices and nano-materials requires comprehensive understanding of their mechanical properties. As observations suggest size dependent behaviour, non-classical theories preserving the memory of body’s internal structure via additional material parameters offer great potential when a continuum modelling is to be preferred. In the present study, micropolar theory of elasticity is adopted due to its peculiar character allowing for incorporation of scale effects through additional kinematic descriptors and work-conjugated stress measures. An optimisation approach is presented to provide unified material parameters for two specific class of single-walled carbon nanotubes (e.g., armchair and zigzag) by minimizing the difference between the apparent shear modulus obtained from molecular dynamics (MD) simulation and micropolar beam model considering both solid and tubular cross-sections. The results clearly reveal that micropolar theory is more suitable compared to internally constraint couple stress theory, due to the essentiality of having skew-symmetric stress and strain measures, as well as to the classical local theory (Cauchy of Grade 1), which cannot accounts for scale effects. To the best of authors’ knowledge, this is the first time that unified material parameters of CNTs are derived through a combined MD-micropolar continuum theory.

Simulation of the Influence of Bonding Materials on the Dynamic Behavior of Laminated Composites

1978 ◽  
Vol 45 (4) ◽  
pp. 822-828 ◽  
Author(s):  
Adnan H. Nayfeh ◽  
Elsayed Abdel-Ati M. Nassar
Keyword(s):  
Wave Propagation ◽  
Dynamic Behavior ◽  
Laminated Composites ◽  
Propagation Process ◽  
Bonding Material ◽  
Mixture Theories

Two model analyses are constructed in order to determine the influence of bonding materials on the dynamic behavior of otherwise bilaminated composites. The geometric arrangement of the composite with the bond is treated as a special type of a trilaminated composite in which each of its major constituents is sandwiched between two bonding layers. In the first model, the recently developed continuum mixture theories of wave propagation in bilaminated composites [2] are extended to treat the trilaminated composite. Here details of the propagation process in the major components and also in the bonding layers are derived. In the second model, the entire effect of the bonds is treated as a modifier to interfacial continuity conditions. In this model the details of the propagation process in the bonding material are ignored. It is found that the results of both models correlate well for relatively thin bonding layers.

Aromatic fluorocarbon mixtures. VI. Vapour pressures of carbon tetrachloride + hexafluorobenzene

1974 ◽  
Vol 27 (10) ◽  
pp. 2159 ◽  
Author(s):  
NF Pasco ◽  
DV Fenby
Keyword(s):  
Carbon Tetrachloride ◽  
Thermodynamic Properties ◽  
Equations Of State ◽  
Liquid Mixture ◽  
Excess Enthalpies ◽  
Molar Excess ◽  
Mixture Theories

Measurements are reported of the vapour pressures of the system carbon tetrachloride + hexafluorobenzene at 278.68 K. The molar excess Gibbs functions GE/M, obtained from these measurements have been combined with previously reported molar excess enthalpies to give GE/M at 298 K. Thermodynamic properties of CCl4+C6F6 at 298 K are compared with the predictions of liquid mixture theories based on analytic equations of state.

scholarly journals On the Modeling of Five-Layer Thin Prismatic Bodies

2019 ◽  
Vol 24 (3) ◽  
pp. 69 ◽  
Author(s):  
Mikhail U. Nikabadze ◽  
Armine R. Ulukhanyan ◽  
Tamar Moseshvili ◽  
Ketevan Tskhakaia ◽  
Nodar Mardaleishvili ◽  
...  
Keyword(s):  
Orthogonal Polynomials ◽  
Boundary Value Problems ◽  
Boundary Value ◽  
Three Dimensional ◽  
Initial Boundary ◽  
Initial Boundary Value Problems ◽  
Micropolar Theory ◽  
Prismatic Bodies ◽  
Initial Boundary Value

Proceeding from three-dimensional formulations of initial boundary value problems of the three-dimensional linear micropolar theory of thermoelasticity, similar formulations of initial boundary value problems for the theory of multilayer thermoelastic thin bodies are obtained. The initial boundary value problems for thin bodies are also obtained in the moments with respect to systems of orthogonal polynomials. We consider some particular cases of formulations of initial boundary value problems. In particular, the statements of the initial-boundary value problems of the micropolar theory of K-layer thin prismatic bodies are considered. From here, we can easily get the statements of the initial-boundary value problems for the five-layer thin prismatic bodies.

A Study of Misaligned Micropolar Lubricated Membrane Compensated Hybrid Journal Bearing System

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Satish C. Sharma ◽  
E. Rajasekhar Nicodemus ◽  
Nathi Ram
Keyword(s):  
Reynolds Equation ◽  
Flow Characteristic ◽  
Journal Bearing ◽  
Lubricating Oil ◽  
Micropolar Theory ◽  
Shaft Deflection ◽  
Journal Misalignment ◽  
Raphson Method ◽  
System Operating ◽  
Bearing System

The present work aims to analytically study the performance of misaligned four-pocket, membrane compensated, hybrid journal bearing system operating with micropolar lubricant. In the present study, the flow characteristic of the lubricating oil containing additives and contaminants has been modeled using Erigen’s micropolar theory. The journal misalignment which may occur as a result of noncentral loading, improper assembly, shaft deflection due to elasticity and thermal distortions, etc. has been accounted for in the present study by defining a pair of misalignment parameters in vertical and horizontal directions (i.e., δ and σ).The modified Reynolds equation governing the flow of micropolar lubricant in the clearance space of a misaligned bearing has been solved using FEM and Newton Raphson method along with the appropriate boundary conditions. The numerically simulated results suggest that the effect of journal misalignment is to cause degradation in bearing performance, whereas the influence of micropolar effect of lubricant is to enhance the bearing performance. Therefore, it is imperative to account for the effect of misalignment and lubricant behavior during the design process in order to generate accurate bearing characteristics data.

Interface modelling of microsystem interconnections using micropolar theory and discontinuous approximation

2007 ◽  
Vol 85 (19-20) ◽  
pp. 1500-1513 ◽  
Author(s):  
Yan Zhang ◽  
Ragnar Larsson ◽  
Jing-yu Fan ◽  
Johan Liu
Keyword(s):  
Micropolar Theory ◽  
Discontinuous Approximation
Sign in / Sign up

Export Citation Format

Share Document