scholarly journals The mem-inerter: A new mechanical element with memory

2018 ◽  
Vol 10 (6) ◽  
pp. 168781401877842 ◽  
Author(s):  
Xiao-liang Zhang ◽  
Qiao Gao ◽  
Jiamei Nie
Keyword(s):  
Performance Comparison ◽  
Forced Response ◽  
Free Response ◽  
Initial Displacement ◽  
Mechanical Element ◽  
Simple Mass ◽  
Pinched Hysteresis Loop ◽  
Mass Spring ◽  
Pinched Hysteresis ◽  
With Memory

A new two-terminal mechanical element named the mem-inerter described by a relation between integrated momentum and displacement is introduced as the memory counterpart of an inerter. It exhibits an individual “fingermark” featured by a pinched hysteresis loop located within the momentum-velocity plane. The mem-inerter is attached to a simple mass-spring-damper system. The system equipped with a mem-inerter is mathematically modeled, and its nonlinear vibration equation is derived. To ensure a fair performance comparison between the systems equipped with the mem-inerter and the inerter, the nonlinear mem-inerter with an appropriate helix pitch can be proved to be equivalent to the linear inerter with a fixed inertance by the fact that the systems have the same displacement transmissibility for forced response. Under such a premise, it is found that the system with the mem-inerter having positive initial displacement has better performance for free response than the system with the inerter. Furthermore, the application scenario that both systems are arranged on an inclined plane is taken as an example of the positive initial displacement. The example demonstrates that the system with the mem-inerter has significantly better transient performance than the system with the inerter.

A Discrete Model to Consider the Influence of the Air Flow on Blade Vibrations of an Integral Blisk Compressor Rotor

2008 ◽  
Author(s):  
Bernd Beirow ◽  
Arnold Ku¨hhorn ◽  
Sven Schrape
Keyword(s):  
Air Flow ◽  
Forced Response ◽  
Response Analysis ◽  
Element Analysis ◽  
Compressor Rotor ◽  
Aerodynamic Properties ◽  
Cascade Arrangement ◽  
Simple Mass ◽  
Mass Spring ◽  
Elastically Supported

The influence of the aerodynamic coupling in the forced response analysis of a HPC test-blisk is studied by means of a reduced order mechanical model. In the first step this equivalent blisk model (EBM) is derived based on a finite element analysis of the disk from design and an adjustment to experimentally determined blade alone frequencies in order to consider the real blade mistuning. Applying the EBM — so far not considering the air flow influence — to carry out forced response analyses due to a rotating excitation acting on the stationary blisk, a maximum blade displacement amplification of more than 50% has been calculated comparing the tuned and the mistuned blisk. Aiming at an additional consideration of the air flow, fully coupled computations of the fluid structure interaction (FSI) are exemplarily carried out for elastically supported blades in a cascade arrangement. The results are used to calibrate simple mass-spring-damper models from which quantities of additional aerodynamic elements in terms of a consideration of co-vibrating air masses, air stiffening and aerodynamic damping are derived. Based on this information the EBM is extended to a so called advanced EBM. Aerodynamic influences are considered assigning the aerodynamic properties to each blade in dependence on the inter blade phase angle (IBPA). Forced response analyses, now including all aerodynamic influences, show that for an extreme application of a rear blisk close to the combustion chamber and under MTO conditions a strong smoothing of originally localized vibration modes occurs. The maximum blade displacement amplification due to mistuning is decreased from more than 50% to below 12% for the first blade flap mode.

scholarly journals Asymptotic Description of Maximum Mistuning Amplification of Bladed Disk Forced Response

2008 ◽  
Vol 131 (2) ◽  
Author(s):  
Carlos Martel ◽  
Roque Corral
Keyword(s):  
Upper Bound ◽  
Amplification Factor ◽  
Forced Response ◽  
Spring Model ◽  
Bladed Disk ◽  
Mass Spring Model ◽  
Amplification Process ◽  
Simple Mass ◽  
Response Amplification ◽  
Mass Spring

The problem of determining the maximum forced response vibration amplification that can be produced just by the addition of a small mistuning to a perfectly cyclical bladed disk still remains not completely clear. In this paper we apply a recently introduced perturbation methodology, the asymptotic mistuning model (AMM), to determine which are the key ingredients of this amplification process and to evaluate the maximum mistuning amplification factor that a given modal family with a particular distribution of tuned frequencies can exhibit. A more accurate upper bound for the maximum forced response amplification of a mistuned bladed disk is obtained from this description, and the results of the AMM are validated numerically using a simple mass-spring model.

Sunpatiens compact hot coral: memristors in flowers

2018 ◽  
Vol 45 (2) ◽  
pp. 222 ◽  
Author(s):  
Alexander G. Volkov ◽  
Eunice K. Nyasani
Keyword(s):  
Hysteresis Loop ◽  
Plasma Membranes ◽  
Hysteresis Loops ◽  
Electrical Current ◽  
Low Frequencies ◽  
Current Voltage ◽  
Pinched Hysteresis Loop ◽  
Pinched Hysteresis ◽  
With Memory

Leon Chua postulated the theory of a memristor – a resistor with memory – in 1971, and the first solid-state memristor was built in 2008. Memristors exist in vivo as components of plasma membranes in plants, fruits, roots and seeds. A memristor is a nonlinear element; its current-voltage characteristic is similar to that of a Lissajous pattern. Here, we found memristors in flowers. Electrostimulation by bipolar periodic sinusoidal or triangular waves of an androecium, a spur, petals and a pedicel in Sunpatiens flowers induces hysteresis loops with a pinched point at low frequencies between 0.1 mHz and 1 mHz. At high frequencies, the pinched hysteresis loop transforms to a non-pinched hysteresis loop instead of a single line I = U/R for ideal memristors because the amplitude of electrical current depends on capacitance of a flower’s tissue and electrodes, frequency and direction of scanning. The discovery of memristors in Sunpatiens (Impatiens spp.) creates a new direction in the modelling and understanding of electrophysiological phenomena in flowers.

scholarly journals Asymptotic Description of Maximum Mistuning Amplification of Bladed Disk Forced Response

2008 ◽  
Author(s):  
Carlos Martel ◽  
Roque Corral
Keyword(s):  
Upper Bound ◽  
Amplification Factor ◽  
Forced Response ◽  
Spring Model ◽  
Bladed Disk ◽  
Mass Spring Model ◽  
Amplification Process ◽  
Simple Mass ◽  
Response Amplification ◽  
Mass Spring

The problem of determining the maximum forced response vibration amplification that can be produced just by the addition of a small mistuning to a perfectly cyclical bladed disk still remains not completely clear. In this paper we apply a recently introduced perturbation methodology, the Asymptotic Mistuning Model (AMM), to determine which are the key ingredients of this amplification process, and to evaluate the maximum mistuning amplification factor that a given modal family with a particular distribution of tuned frequencies can exhibit. A more accurate upper bound for the maximum forced response amplification of a mistuned bladed disk is obtained from this description, and the results of the AMM are validated numerically using a simple mass-spring model.

Elastic moduli of simple mass spring models

2014 ◽  
Vol 31 (10) ◽  
pp. 1339-1350 ◽  
Author(s):  
Maciej Kot ◽  
Hiroshi Nagahashi ◽  
Piotr Szymczak
Keyword(s):  
Elastic Moduli ◽  
Simple Mass ◽  
Mass Spring

scholarly journals CMOS Realization of All-Positive Pinched Hysteresis Loops

Complexity ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
B. J. Maundy ◽  
A. S. Elwakil ◽  
C. Psychalinos
Keyword(s):  
Hysteresis Loop ◽  
Detailed Analysis ◽  
Hysteresis Loops ◽  
Nonlinear Circuits ◽  
Experimental Results ◽  
First Order ◽  
Pinched Hysteresis Loop ◽  
A Charge ◽  
Pinched Hysteresis ◽  
Nmos Transistors

Two novel nonlinear circuits that exhibit an all-positive pinched hysteresis loop are proposed. These circuits employ two NMOS transistors, one of which operates in its triode region, in addition to two first-order filter sections. We show the equivalency to a charge-controlled resistance (memristance) in a decremental state via detailed analysis. Simulation and experimental results verify the proposed theory.

A Novel Floating/Grounded Meminductor Emulator

2020 ◽  
Vol 29 (15) ◽  
pp. 2050247 ◽  
Author(s):  
Hasan Sozen ◽  
Ugur Cam
Keyword(s):  
Hysteresis Loop ◽  
Operational Amplifier ◽  
Current Conveyors ◽  
Current Feedback ◽  
Transconductance Amplifier ◽  
Additional Control ◽  
Pinched Hysteresis Loop ◽  
Terminal Element ◽  
Current Feedback Operational Amplifier ◽  
Pinched Hysteresis

Meminductor is a nonlinear two-terminal element with storage energy and memory ability. To date, meminductor element is not available commercially as memristor and memcapacitor are. Therefore, it is of great significance to implement a meminductor emulator for breadboard experiment. In this paper, a flux-controlled floating/grounded meminductor emulator without a memristor is presented. It is built with commercially available off-the-shelf electronic devices. It consists of single operational transconductance amplifier (OTA), single multiplier, two second-generation current conveyors (CCIIs), single current-feedback operational amplifier (CFOA) and single operational amplifier. Using OTA device introduces an additional control parameter besides frequency and amplitude values of applied voltage to control the area of pinched hysteresis loop of meminductor. Mathematical model of proposed emulator circuit is given to describe the behavior of meminductor circuit. The breadboard experiment is performed using CA3080, AD844, AD633J and LM741 for OTA, CCII–CFOA, multiplier and operational amplifier, respectively. Simulation and experimental test results are given to verify the theoretical analyses. Frequency-dependent pinched hysteresis loop is maintained up to 5 kHz. The presented meminductor emulator tends to work as ordinary inductor for higher frequencies.

The Hanging Column as a Dynamic Vibration Absorber

2018 ◽  
Vol 18 (07) ◽  
pp. 1871008 ◽  
Author(s):  
C. Y. Wang
Keyword(s):  
Forced Vibration ◽  
Vibration Absorber ◽  
Initial Value ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Spring System ◽  
Simple Mass ◽  
Mass Spring ◽  
First Time

A simple mass–spring system with an attached hanging column is investigated. The problem is formulated and the frequencies obtained with an efficient initial value method. Under forced vibration, the amplitude of the mass may be greatly reduced by adding a hanging column. The possibility of using such a hanging column as a dynamic vibration absorber is shown for the first time.

Fabric Simulation Using Measurement Data for Dress Design

2014 ◽  
Author(s):  
Ayumi Hara ◽  
Hideki Aoyama ◽  
Tetsuo Oya
Keyword(s):  
Mechanical Properties ◽  
Evaluation System ◽  
Contact Point ◽  
Measurement Data ◽  
Previous Method ◽  
The State ◽  
Design Element ◽  
Simple Mass ◽  
Mass Spring ◽  
Fashion Designers

The state of wrinkles and folds formed on our dress according to human postures and movements is an important design element. Fashion designers must envisage the fabric state as wrinkling and folding. However, this is not easy because the fabric state strongly depends on the mechanical properties of the fabric, and in this sense, fabric simulation can aid designers in envisaging the fabric state. In previous works on fabric simulation, fabric models are proposed and developed based on the simple mass spring model. Since none of the models proposed so far take into account the state of slipping at the contact point of the warp and weft, simulated results differ from real fabric states. This paper proposes a method to simulate real fabric state taking into consideration slipping. In order to obtain real simulation results, the mechanical properties of fabric obtained by KES: Kawabata Evaluation System [1], were used in the simulation. The effectiveness of the proposed model was confirmed by comparing simulated results obtained by the proposed method with simulated results obtained by a previous method. In addition, it was verified by comparing the simulated results obtained by the proposed method with real cloth states.

A Novel Bipolar Photon-Controlled Generalized Memristor Based on Avalanche Photodiode

2020 ◽  
pp. 2150090
Author(s):  
Jianxiu Hao ◽  
Xiangliang Jin ◽  
Bo Peng
Keyword(s):  
Topological Structure ◽  
Hysteresis Loops ◽  
Avalanche Photodiode ◽  
Circuit Model ◽  
Traditional Model ◽  
Circuit Simulator ◽  
Dynamical Characteristics ◽  
Spice Model ◽  
Pinched Hysteresis Loop ◽  
Pinched Hysteresis

A novel bipolar photon-controlled generalized memristor model with an avalanche photodiode (APD) passive quenching circuit is presented in this paper. The SPICE model of the circuit is established and its fingerprints are analyzed by the pinched hysteresis loops with different bipolar periodic stimuli. The dynamical characteristics of the proposed circuit model are investigated both theoretically and simulatively. The results verified by Cadence Spectre circuit simulator demonstrate that the proposed circuit model is a simple bipolar photon-controlled generalized memristor. Compared with the previously published memristor models, the biggest innovation of this paper is to propose a bipolar generalized memristor model instead of the traditional model, which can easily form the pinched hysteresis loop. Another highlight is that the generalized memristor model in this paper is controlled by photons while conventional memristors are charge-controlled/flux-controlled. Furthermore, the circuit level models are more stable, more reliable and more resistant to interference than the device level models. The topological structure of the proposed circuit model in this paper is much more simpler.

Sign in / Sign up

Export Citation Format

Share Document