scholarly journals Micromechanical Analysis in Applications of Active Mono-Slip and Continuum Dislocations in the MDCM

2021 ◽  
Vol 11 (7) ◽  
pp. 3135
Author(s):  
Temesgen Takele Kasa
Keyword(s):  
Energy Dissipation ◽  
Slip System ◽  
Energy Minimization ◽  
Variational Calculus ◽  
Small Strain ◽  
Zero Energy ◽  
Dissipation Energy ◽  
Optimal Analysis ◽  
Wolfram Mathematica ◽  
Minimization Technique

The key purpose of this paper is to propose a mono-slip-dependent continuum dislocation method for matrix-dominated composite structure (MDCS) analysis. The methodology focuses on dissipation energy theories utilizing a continuum dislocation method (CDM) integrated with small-strain kinematics. The mathematical modeling of the CDM comprises active mono-slip system formulations, thermodynamic dislocation analysis (TDA), free energy dissipation analysis, and the progression of dislocations. Furthermore, zero and non-zero energy dissipation due to dislocation progression is formulated by using an energy minimization technique with variational calculus. The numerical analysis, performed with Wolfram Mathematica©, is presented using zero and non-zero energy dissipation energy formulations. The outcomes indicate that the formulated approach can be effective for obtaining optimal analysis results for matrix-dominated composite (MDC) materials with a mono-slip system. In sum, this study confirms the feasibility of using the proposed approach to investigate MDCS with inclusions.

scholarly journals Cost-Optimal Analysis for Nearly Zero Energy Buildings Design and Optimization: A Critical Review

Energies ◽  
2018 ◽  
Vol 11 (6) ◽  
pp. 1478 ◽  
Author(s):  
Maria Ferrara ◽  
Valentina Monetti ◽  
Enrico Fabrizio
Keyword(s):  
Critical Review ◽  
Zero Energy ◽  
Design And Optimization ◽  
Optimal Analysis ◽  
Zero Energy Buildings

Justifying the Stabilization of a Marginally Stable Ship

2017 ◽  
Author(s):  
David Shekhtman ◽  
Dirk M. Luchtenburg
Keyword(s):  
Energy Dissipation ◽  
Closed Loop ◽  
Equations Of Motion ◽  
Marginal Stability ◽  
Stability Conditions ◽  
Stability Criteria ◽  
Benchmark Problem ◽  
Zero Energy ◽  
External Disturbances ◽  
Lyapunov Stability Criteria

As a precursor to capsize, marginal stability, resulting from incorrect loading conditions and crew negligence, poses a serious danger to ships. Therefore, as a benchmark problem for preventing capsize, the use of an actively controlled pendulum for the stabilization of a marginally stable ship was analyzed. Lyapunov stability criteria and closed loop eigenvalues were used to evaluate the extent to which a proposed pendulum controller could cope with different ship stability conditions. Equations of motion were solved to observe the controller’s performance under different damping conditions. The behavior of the controller yielded the following results: a marginally stable ship can be stabilized, as long as there is no right hand plane zero; energy dissipation is key to the stabilization of a marginally stable ship; the controller must have knowledge of the ship’s stability to prevent controller-induced excitation; and a stabilized tilted ship is more robust to external disturbances than a stabilized upright ship.

Large-Strain Axisymmetric Deformation of Cylindrical Shells

1987 ◽  
Vol 54 (2) ◽  
pp. 287-291 ◽  
Author(s):  
G. W. Brodland ◽  
H. Cohen
Keyword(s):  
Nonlinear Equations ◽  
Energy Minimization ◽  
Parametric Analysis ◽  
Large Strain ◽  
Cylindrical Shells ◽  
Radial Force ◽  
Axisymmetric Deformation ◽  
The Other ◽  
Large Strains ◽  
Minimization Technique

Nonlinear equations are derived for the axisymmetric deformation of thin, cylindrical shells made of Mooney-Rivlin materials and subject to arbitrarily large strains and rotations. These equations are then implemented numerically using an energy minimization technique. Finally, an extensive parametric analysis is done of cylindrical shells which are clamped at one end and loaded with either a radial force or an edge moment uniformly distributed along the circumference of the other end.

Finite Temperature Quasicontinuum Methods

1998 ◽  
Vol 538 ◽  
Author(s):  
Vivek Shenoy ◽  
Vijay Shenoy ◽  
Rob Phillips
Keyword(s):  
Free Energy ◽  
Energy Minimization ◽  
Finite Temperature ◽  
Degrees Of Freedom ◽  
Elastic Moduli ◽  
Dislocation Core ◽  
Minimization Method ◽  
Free Energy Minimization ◽  
Minimization Technique ◽  
Frame Work

AbstractIn this paper we extend the quasi-continuum method to study equilibrium properties of defects at finite temperatures. We present a derivation of an effective energy function to perform Monte Carlo simulations in a mixed atomistic and continuum setting. It is shown that the free energy minimization technique can be easily incorporated into the quasi-continuum frame work, permitting a reduction of the full set of atomistic degrees of freedom even in the finite temperature setting. The validity of the proposed methods is demonstrated by computing the thermal expansion and the temperature dependence of the elastic moduli for Cu. We also employ the quasi-continuum free energy minimization method to study the finite temperarure structure of a dislocation core in Al.

FAVORABLE SILICA MONOLAYER STRUCTURES ON THE Mo(112) SURFACE

2005 ◽  
Vol 12 (03) ◽  
pp. 449-456 ◽  
Author(s):  
I. N. YAKOVKIN
Keyword(s):  
Total Energy ◽  
Density Of States ◽  
Energy Minimization ◽  
Phonon Frequency ◽  
Experimental Results ◽  
Minimization Technique ◽  
Oxygen Atoms

Favored structures of SiO n monolayers on Mo (112) surface have been studied using the total energy minimization technique based on DFT semirelativistic approach. In the [ SiO 4] complexes, which form the c (2 × 2) silica structure on the Mo (112), the bonding of the Si atoms with the surface is accomplished through the oxygen atoms. The structure with a symmetric position of oxygen atoms has been found to be the most favorable. In this structure, two oxygen atoms occupy bridge-on-row sites on the Mo (112) surface, with Si atoms between them, while oxygen atoms in the troughs appear not in expected threefold sites, but adjust their positions along the middle lines of the troughs. Estimated main phonon frequency and density of states for the symmetric [ SiO 4] structure agree well with experimental results.

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