scholarly journals Changes in post critical equilibrium and localization effects of elastic elongated plates

2018 ◽  
Vol 456 ◽  
pp. 012078
Author(s):  
G A Manuilov ◽  
S B Kositsyn ◽  
M M Begichev
Keyword(s):  
Critical Equilibrium

Problem behavior in autism spectrum disorders: A paradigmatic self-organized perspective of network structures

2019 ◽  
Vol 42 ◽  
Author(s):  
Lucio Tonello ◽  
Luca Giacobbi ◽  
Alberto Pettenon ◽  
Alessandro Scuotto ◽  
Massimo Cocchi ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Problem Behaviors ◽  
Autism Spectrum ◽  
The Self ◽  
Network Structures ◽  
Self Organized ◽  
Critical Equilibrium ◽  
Self Organized Criticality ◽  
Acute Agitation ◽  
Spectrum Disorders

AbstractAutism spectrum disorder (ASD) subjects can present temporary behaviors of acute agitation and aggressiveness, named problem behaviors. They have been shown to be consistent with the self-organized criticality (SOC), a model wherein occasionally occurring “catastrophic events” are necessary in order to maintain a self-organized “critical equilibrium.” The SOC can represent the psychopathology network structures and additionally suggests that they can be considered as self-organized systems.

scholarly journals Analysis of the Functionally Step-Variable Graded Plate Under In-Plane Compression

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4090 ◽  
Author(s):  
Leszek Czechowski ◽  
Zbigniew Kołakowski
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Functionally Graded ◽  
The Finite Element Method ◽  
Graded Materials ◽  
Number Of Layers ◽  
Critical Equilibrium ◽  
Post Buckling ◽  
Plane Compression

A study of the pre- and post-buckling state of square plates built from functionally graded materials (FGMs) and pure ceramics is presented. In contrast to the theoretical approach, the structure under consideration contains a finite number of layers with a step-variable change in mechanical properties across the thickness. An influence of ceramics content on a wall and a number of finite layers of the step-variable FGM on the buckling and post-critical state was scrutinized. The problem was solved using the finite element method and the asymptotic nonlinear Koiter’s theory. The investigations were conducted for several boundary conditions and material distributions to assess the behavior of the plate and to compare critical forces and post-critical equilibrium paths.

On the critical equilibrium of the spiral spring pendulum

2009 ◽  
Vol 466 (2114) ◽  
pp. 407-421 ◽  
Author(s):  
P. Coullet ◽  
J.-M. Gilli ◽  
G. Rousseaux
Keyword(s):  
Nonlinear Oscillator ◽  
Inverted Pendulum ◽  
Physical Systems ◽  
Supercritical Bifurcation ◽  
Euler Elastica ◽  
Critical Equilibrium ◽  
Spiral Spring ◽  
Joseph Larmor ◽  
Angular Amplitude ◽  
First Time

Physical systems such as an inverted pendulum driven by a spiral spring, an unbalanced Euler elastica with a travelling mass, a heavy body with a parabolic section and an Ising ferromagnet are very different. However, they all behave in the same manner close to the critical regime for which nonlinearities are prominent. We demonstrate experimentally, for the first time, an old prediction by Joseph Larmor, which states that a nonlinear oscillator close to its supercritical bifurcation oscillates with a period inversely proportional to its angular amplitude. We perform our experiments with a Holweck–Lejay-like pendulum which was used to measure the gravity field during the twentieth century.

Numerical Studies of Magnetohydrostatic Finite-Beta Stellarator Equilibria

1982 ◽  
Vol 37 (8) ◽  
pp. 879-890 ◽  
Author(s):  
F. Herrnegger
Keyword(s):  
Aspect Ratio ◽  
Three Dimensional ◽  
Pressure Profile ◽  
Large Aspect Ratio ◽  
Weak Effect ◽  
Numerical Convergence ◽  
Secondary Currents ◽  
Numerical Studies ◽  
Critical Equilibrium ◽  
Theoretical Predictions

Properties of finite-beta stellarator equilibria are investigated which are obtained as fully three-dimensional finite-beta solutions of the magnetohydrostatic boundary value problem with the help of the code by Bauer, Betancourt, and Garabedian based on the energy method. In the case of slender l = 2 stellarator equilibria the displacement of the magnetic axis as well as its helical deformation as functions of beta are found to be close to the known theoretical predictions which were derived for slender low beta l = 2 configurations of large aspect ratio. In the case of l = 2 stellarators with moderate aspect ratio the shear has a weak effect on the displacement in contradiction to results from asymptotic theories. A class of l = 0, 1, 2, 3 configurations with reduced secondary currents could be found showing axis displacements which are at least a factor of three smaller than those in pure l = 2 stellarators. A critical equilibrium beta value of βe(0) = 0.045 has been estimated in the W VII-AS stellarator for a bell-shaped pressure profile. Extensive numerical convergence studies are presented

A Simplified Method for Calculating Ultimate Strength of Pressure Hull in Deep-Sea Manned Submersible

2012 ◽  
Vol 160 ◽  
pp. 17-24
Author(s):  
Li Hao Yuan ◽  
Zhi Xin Xiong ◽  
Lei Song ◽  
Zhi Hui Dong
Keyword(s):  
Strain Energy ◽  
Strain Curve ◽  
Initial Imperfection ◽  
Dimensionless Number ◽  
Stress Strain Curve ◽  
Critical Equilibrium ◽  
Simplified Method ◽  
Manned Submersible ◽  
Utilization Ratio ◽  
Strain Energy Density Theory

Based on the strain energy density theory, the connotation of tangent modulus theory is developed. At critical equilibrium state, a dimensionless number Φt of a structure under pressure is introduced in this paper. Derived from the stress-strain curve of material, a four-parameter formula that contains Φt is established. This formula is referred to as the function of strength utilization ratio that may be used for calculating the inelastic buckling of deep submersible pressure hull.Φt can be used to express the effect of initial imperfection of the shell and to guide the experimental study. Compared with the data from some experiments or other methods, it has demonstrated that the method given by this paper is more precise and convenient for predicting the failure of thin and moderately thick shell under pressure.

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