A Non-linear Input Converter Inversely Pre-distorted Against Nonlinear Behavior of FG-based Neuromorphic Synaptic Devices

2021 ◽  
Author(s):  
Jin-Young Hwang ◽  
Kee-Won Kwon
Keyword(s):  
Nonlinear Behavior ◽  
Non Linear

ISUM: Its Birth, Growth and Future

2016 ◽  
Author(s):  
Sherif Rashed
Keyword(s):  
Nonlinear Behavior ◽  
Impact Loads ◽  
Coarse Mesh ◽  
Structural Units ◽  
Large Size ◽  
Linear Behavior ◽  
Large Ship ◽  
Non Linear ◽  
Recent Developments ◽  
Future Potential

ISUM (The Idealized Structural Unit Method) was born in 1972 to efficiently and accurately analyze the behavior of large size structures up to and beyond their ultimate strength. In this method a structure is divided into large elements, basically its structural units (members). Geometric and material non-linear behavior inside the element is formulated and expressed at a limited number of nodal points at the element boundaries. In this way a large structure can be modeled using a coarse mesh while still being able to consider the nonlinear behavior until the collapse of the structure. Several ISUM elements have been formulated and used to analyze the non-linear behavior of large ship structures. In further developments, more elements with more accurate formulations have been developed and more types of structures have been analyzed using this method. The same ISUM concept has been applied to the analysis of welding deformation of large welded structures and to failure analysis of structural and mechanical components subjected to impact loads. In this paper, the basic ISUM concept is outlined, and several elements are presented. Examples of applications to ships and marine structures are presented demonstrating the effectiveness of the method. Recent developments are also reviewed and future potential is explored.

Miraculous Agitations: On the Uses of Chaotic, Non-Linear and Emergent Behavior in Acoustic Vibrating Physical Systems

2012 ◽  
Vol 22 ◽  
pp. 35-40 ◽  
Author(s):  
Daniel Wilson
Keyword(s):  
Music Composition ◽  
Nonlinear Behavior ◽  
Qualitative Approach ◽  
Emergent Behavior ◽  
New Music ◽  
Physical Systems ◽  
Non Linear ◽  
Subjective Phenomenon

“Miraculous agitation” denotes an acoustic marvel: a striking sound emerging from vibrating physical systems. A somewhat subjective phenomenon, acoustic marvels are typified by expressive or harmonic richness, and their production is reliant on delicate interrelationships between objects under vibration, often involving chaotic or nonlinear behavior. In some cases it is even possible to observe emergent behavior. Significantly, acoustic marvels may commonly strike the auditor as seeming to be “of electronic origin,” thus pointing toward postelectronic electroacoustic techniques. This paper takes a qualitative approach to the examination of such acoustic marvels and their possible applications in new music composition.

Nonlinear Vibrations and Instability of Shallow Pyramidal Trusses

2015 ◽  
Author(s):  
Carlos Henrique L. de Castro ◽  
Paulo B. Gonçalves ◽  
Diego Orlando
Keyword(s):  
Carbon Nanostructures ◽  
Nonlinear Vibrations ◽  
Nonlinear Behavior ◽  
Basins Of Attraction ◽  
Dynamic Loads ◽  
Phase Portraits ◽  
Major Influence ◽  
Non Linear ◽  
Static And Dynamic Loads ◽  
Von Mises

Pyramidal space trusses are a basic component of several structures, from carbon nanostructures to large geodesic domes. These structures, such as the classical Von Mises truss, have a highly non-linear response in the presence of static and dynamic loads. The geometric nonlinearity is particularly significant, even at low load levels when these structures are shallow, that is, has a small height to base ratio. This paper presents an exact non-linear formulation for a shallow pyramidal truss composed of n equally spaced bars. Based on this formulation, the loss of stability and nonlinear vibrations of these structures under static and dynamic loads is analyzed. To understand its nonlinear behavior, time responses, phase portraits, bifurcation diagrams, energy profiles and basins of attraction are obtained. The results highlight the complex nonlinear dynamics of this class of structures and its major influence in design.

scholarly journals Non-Linear Behaviors of Transient Periodic Plasma Dynamics in a Multifractal Paradigm

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1356
Author(s):  
Stefan-Andrei Irimiciuc ◽  
Alexandra Saviuc ◽  
Florin Tudose-Sandu-Ville ◽  
Stefan Toma ◽  
Florin Nedeff ◽  
...  
Keyword(s):  
Period Doubling ◽  
Nonlinear Behavior ◽  
Structural Units ◽  
Plasma Dynamics ◽  
Oscillatory Dynamics ◽  
Damped Oscillations ◽  
Hidden Symmetry ◽  
Non Linear ◽  
Transient Plasma ◽  
Newtonian Behavior

In a multifractal paradigm of motion, nonlinear behavior of transient periodic plasmas, such as Schrodinger and hydrodynamic-type regimes, at various scale resolutions are represented. In a stationary case of Schrodinger-type regimes, the functionality of “hidden symmetry” of the group SL (2R) is implied though Riccati–Gauge different “synchronization modes” among period plasmas’ structural units. These modes, expressed in the form of period doubling, damped oscillations, quasi-periodicity, intermittences, etc., mimic the various non-linear behaviors of the transient plasma dynamics similar to chaos transitions scenarios. In the hydrodynamic regime, the non-Newtonian behavior of the transient plasma dynamics can be corelated with the viscous tension tensor of the multifractal type. The predictions given by our theoretical model are confronted with experimental data depicting electronic and ionic oscillatory dynamics seen by implementing the Langmuir probe technique on transient plasmas generated by ns-laser ablation of nickel and manganese targets.

Effects of Pile-Soil Interaction on Push-Over Analysis of Jacket Type Offshore Platforms

2006 ◽  
Author(s):  
B. Asgarian ◽  
M. Lesani
Keyword(s):  
Pushover Analysis ◽  
Soil Layer ◽  
Nonlinear Behavior ◽  
Offshore Structures ◽  
Offshore Platforms ◽  
Lateral Loads ◽  
Wave Load ◽  
Linear Behavior ◽  
Non Linear ◽  
Load Pattern

Pushover analysis is performed to determine the capacity of jacket type offshore structures subjected to lateral loads. Overall behavior of the platform in the nonlinear range of deformation can be observed from pushover analysis results. This analysis can be used for the platform capacity assessment. For performing pushover analysis, nonlinear behavior of structural elements and lateral load pattern should be obtained. Both displacement and load control type of the analysis can be performed. One of the important aspects of pushover analysis is the non-linear behavior of the underlying soil and its interaction with the pile. In this paper pushover analysis of sample jacket type offshore platforms considering pile soil interaction (PSI) is performed. In the pushover analysis performed, fiber elements are used for the modeling of the member and soil nonlinearities. Actual soil layer properties, which have been derived from geotechnical reports, are incorporated in the model using fiber elements of “DRAIN-3DX” software. Each soil layer is presented by an equivalent fiber element, having the same characteristics of the relevant soil. The pile structure from top elevation until its tip together with other jacket components including the legs and braces are also introduced by fiber elements. Push over analysis is performed for the platforms subjected to wave load pattern. In order to compare the Pile-Soil Interaction (PSI) effects, all of the analyses are also performed using fixed and pinned pile ends at mud line elevation and pile stubs. The significance of the Pile-Soil Interaction and soil non-linear behavior is pointed out from this comparison and analysis results.

Building Up Suitable Contact Forces in Integrally Shrouded Blade Rows for Reducing Vibration Amplitudes

2013 ◽  
Author(s):  
Nicolò Bachschmid ◽  
Emanuel Pesatori ◽  
Simone Bistolfi ◽  
Massimiliano Sanvito
Keyword(s):  
Nonlinear Behavior ◽  
Excitation Amplitude ◽  
Contact Forces ◽  
Free Standing ◽  
Beneficial Effects ◽  
Modal Model ◽  
Blade Row ◽  
Non Linear ◽  
Dynamic Magnification Factor ◽  
Selection Of

The beneficial effects of the contact between shrouds are described extensively in recent literature: natural blade frequencies are increased and additional damping is available. Different models are proposed for analyzing its linear and nonlinear behavior, selection of optimum contact forces are proposed for reducing vibration amplitudes to a minimum. Results from different non linear analyses that use different models all based generally on a reduced modal model of the blade row and on the harmonic balance approach for modeling the non linear contact forces, are sometimes contradictory: some claim e.g. that increasing excitation amplitude leads to a reduction of the dynamic magnification factor (due to friction damping increase) some other claim the opposite. The contribution to this topic of the present paper is the analysis of the effect of a “contact shim” which can be inserted in a cavity between adjacent shrouds. The shim generates suitable contact forces between the shrouds of the blades of a row, which without shim would vibrate as free standing blades.

scholarly journals Harmonic-Modal Hybrid Reduced Order Model for the Efficient Integration of Non-Linear Soil Dynamics

2020 ◽  
Vol 10 (19) ◽  
pp. 6778 ◽  
Author(s):  
Claudia Germoso ◽  
Jean Louis Duval ◽  
Francisco Chinesta
Keyword(s):  
Site Response ◽  
Laboratory Data ◽  
Nonlinear Behavior ◽  
Forced Response ◽  
Equivalent Linearization ◽  
Response Analysis ◽  
Damping Factor ◽  
Alternative Analysis ◽  
Soil Response ◽  
Non Linear

Nonlinear behavior of soils during a seismic event has a predominant role in current site response analysis. Soil response analysis, and more concretely laboratory data, indicate that the stress-strain relationship of soils is nonlinear and exhibits hysteresis. An equivalent linearization method, in which non-linear characteristics of shear modulus and damping factor of soils are modeled as equivalent linear relations of the shear strain is usually applied, but this assumption, however, may lead to a conservative approach of the seismic design. In this paper, we propose an alternative analysis formulation, able to address forced response simulation of soils exhibiting their characteristic nonlinear behavior. The proposed approach combines ingredients of modal and harmonic analyses enabling efficient time-integration of nonlinear soil behaviors based on the offline construction of a dynamic response parametric solution by using Proper Generalized Decomposition (PGD)-based model order reduction technique.

scholarly journals Circuit Implementation and Synchronization Control of Chaotic Horizontal Platform Systems by Wireless Sensors

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Meei-Ling Hung ◽  
Her-Terng Yau
Keyword(s):  
Sliding Mode Control ◽  
Earthquake Engineering ◽  
Wireless Sensors ◽  
Electronic Circuit ◽  
Sliding Mode ◽  
Nonlinear Behavior ◽  
Mode Control ◽  
Electronic Circuitry ◽  
Linear Behavior ◽  
Non Linear

Horizontal platform system (HPS) produces a nonlinear behavior from precision machinery systems. This mechanical system is implemented mainly in offshore areas or earthquake engineering. However, elucidating or controlling this non-linear behavior of mechanical systems is extremely difficult and time consuming. Therefore, in addition to developing an electronic circuit to implement HPS, this work designs a sliding mode control (SMC) for synchronizing the state trajectories of two horizontal platform systems, subsequently allowing us to easily understand the HPS, perform more detailed analysis, and achieve further control. Experimental results demonstrate the feasibility of implementing the HPS by the proposed electronic circuit system. Comparing the proposed electronic circuitry designs and the HPS of computer simulation reveals that the results of the non-linear dynamic behavior correlate well with each other. Finally, based on use of the control technology, master-slave chaos synchronization with sliding mode control is achieved by wireless sensors.

Vibrations of a Non Jeffcott Rotor with One Non Linear Bearing

2012 ◽  
Vol 232 ◽  
pp. 450-455
Author(s):  
Akash Vardhan
Keyword(s):  
Mathematical Model ◽  
Nonlinear Behavior ◽  
Feedback Controller ◽  
Magnetic Bearings ◽  
Electromagnetic Actuator ◽  
Entire System ◽  
Mechanical Contact ◽  
Jeffcott Rotor ◽  
Non Linear ◽  
Pulling Forces

Magnetic bearings support a body by mechanical pulling forces without any mechanical contact. They consist of an electromagnetic actuator, position sensors, power amplifiers and feedback controller. All of these components are characterized by nonlinear behavior and hence the entire system is inherently nonlinear. This paper presents a mathematical model for the vibrations of a non-Jeffcott type rotor supported on a non-linear bearing. The model can be used as a reference for systems supported on nonlinear bearings like magnetic bearings.

scholarly journals Study of the compressive strength of concrete block prisms: stack and running bond

2011 ◽  
Vol 4 (3) ◽  
pp. 347-358 ◽  
Author(s):  
G. Mohamad ◽  
P.B. Lourenço ◽  
H. R. Roman
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Peak Load ◽  
Nonlinear Behavior ◽  
Concrete Block ◽  
Progressive Increase ◽  
Biaxial Stress ◽  
Lateral Strain ◽  
Element Analysis ◽  
Non Linear

The main goal of this work is to investigate the nonlinear behavior of concrete block masonry prisms under compression, with an emphasis in the prism deformability and the failure modes. A total of 18 stack-bonded prisms have been tested, using hollow blocks of a single geometry and two different mortar types. To investigate the effect of vertical joints, the bond pattern - stack and running bond - in the prism was varied, by using half units. Finite element analysis of hollow masonry prisms was done utilizing a commercial non-linear finite element code DIANA. The numerical simulation were carried out using non-linear two dimensional 8-node elements and the biaxial stress state material was modeled by a combination of the yield conditions of Rankine and Drucker-Prager. The numerical and experimental results were compared to validate the ability to predict deformation and peak load. The results show that an analytical model cannot be formulated without understanding the interaction between block and mortar. It was observed that: the non-linearities of the masonry correspond to an increase in the lateral strain due to extensive cracking of the material and a progressive increase in the ratio between lateral and axial strains.; the cracks in the three block stacked prisms constructed with a stronger mortar were vertical on both sides; the prisms constructed with a weaker mortar had, as a consequence of localized crushing, also vertical cracks due to stress concentration at some points; the presence of a vertical joint in the prism led to the appearance of separation cracks between the middle block and the vertical mortar joint.

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