scholarly journals Piezoelectric time delayed control for nonlinear vibration of nanobeams

2020 ◽  
pp. 146134842092557
Author(s):  
Canchang Liu ◽  
Qingmei Gong ◽  
Yingchao Zhou ◽  
Changcheng Zhou
Keyword(s):  
Time Delay ◽  
Nonlinear Vibration ◽  
Axial Force ◽  
Primary Resonance ◽  
Critical Voltage ◽  
Control Effect ◽  
Critical Position ◽  
Vibration Effect ◽  
Multi Scale ◽  
Governing Differential Equation

The nonlinear vibration effect of nanobeam and problem of the pull-in between the nanobeam and driven plate are the factors which prevent nano-resonator from improving the performance. The nonlinear governing differential equation is built by considering the axial force with piezoelectric controller. The piezoelectric time-delay electrostatic pull-in control is studied and the first-order approximate solution of nonlinear equation is gotten by using the method of multi-scale. The amplitude–frequency and phase frequency response equation of nonlinear vibration system are given for the primary resonance response of the nanobeam. The relationship between the control effect and feedback control parameters is studied. It is found that the piezoelectric time-delay control can change the critical voltage but not the critical position. The axial force can affect the performance of nanobeam.

Axial Load on the Submarine Pipeline Suspended Law of Vortex Induced Vibration

2011 ◽  
Vol 94-96 ◽  
pp. 1511-1514
Author(s):  
Yi Fei Yan
Keyword(s):  
Natural Frequency ◽  
Axial Force ◽  
Scientific Basis ◽  
Oil Field ◽  
Span Length ◽  
Submarine Pipeline ◽  
Vortex Induced Vibration ◽  
Vibration Effect ◽  
Pipeline Vibration ◽  
The Impact

The study is about submarine pipeline. Considering the impact of different axial force, The reduced velocity is introduced as the pipeline vibration effect of vortex trail releasing. The vibration parameters of the span pipeline are analyzed and vibration control formula is built. The natural span length of the submarine pipeline is calculated according to the DNV-OS-F101 rule. The natural frequency of the span pipeline and the allowable span length are solved. The case study of submarine pipeline in Chengdao oil field is made and the variation law of natural frequency of span pipeline is got. The stream reduced velocity decreases as the axial force increase. The theory analysis of the vortex induced vibration can provide the scientific basis for the safety design of offshore submarine pipeline.

scholarly journals Experimental Study on the Vibration Control Effect of Long Elastic Sleeper Track in Subways

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaopei Cai ◽  
Dacheng Li ◽  
Yanrong Zhang ◽  
Qian Miao ◽  
Rixin Cui
Keyword(s):  
Vibration Reduction ◽  
Field Tests ◽  
Urban Rail Transit ◽  
Control Effect ◽  
Tunnel Wall ◽  
Vibration Effect ◽  
Urban Rail ◽  
Vertical Displacements ◽  
Curved Track ◽  
Reduction Effect

The vibration effect of urban rail transit has gained attention from both academia and the industry sector. Long Elastic Sleeper Track (LEST) is a new structure for vibration reduction which has recently been designed and applied to Chinese subways. However, little research has been devoted to its vibration reduction effect. In this study, field tests were conducted during peak transit hours on Beijing Subway Line 15 to examine the vibration reduction effects of the common ballastless track and LEST on both straight and curved sections. The results demonstrate that although LEST increases the wheel-rail vertical forces, rail vertical displacements, and rail accelerations to some extent, these effects do not threaten subway operational safety, and vibrations of track bed and tunnel wall are positively mitigated. LEST has an obvious vibration reduction effect at frequencies above 40 Hz. In straight track, the vibration of bottom of the tunnel wall measured in one-third octave bands is reduced by 10.52 dB, while the vibration at point on the tunnel wall at 1.5 m height is reduced by 9.60 dB. For the curved track, the vibrations at those two points are reduced by 9.35 dB and 8.44 dB, respectively. This indicates that LEST reduces vibrations slightly more for the straight track than for the curved track.

Influence of Axial Force and Initial Curvature on the Flexural Deflection of Euler-Bernoulli Beam Structures Solved by DQEM Using EDQ

2006 ◽  
Author(s):  
Chang-New Chen
Keyword(s):  
Axial Force ◽  
Offshore Structures ◽  
Differential Quadrature ◽  
Analysis Model ◽  
Bernoulli Beam ◽  
Beam Structures ◽  
Initial Curvature ◽  
Differential Quadrature Element Method ◽  
Governing Differential Equation ◽  
Euler Bernoulli Beam

The influence of axial force and initial curvature on the flexural deflection of Euler-Bernoulli beam structures is analyzed by differential quadrature element method (DQEM) using extended differential quadrature (EDQ). The DQEM uses the differential quadrature to discretize the governing differential equation defined on each element, the transition conditions defined on the inter-element boundary of two adjacent elements and the boundary conditions of the beam. Numerical results solved by the developed numerical algorithm are presented. The convergence of the developed DQEM analysis model is efficient. The theory presented in the paper can be used to effectively obtain accurate results in analyzing the offshore structures.

scholarly journals The Optimized Multi-Scale Permutation Entropy and Its Application in Compound Fault Diagnosis of Rotating Machinery

Entropy ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 170 ◽  
Author(s):  
Xianzhi Wang ◽  
Shubin Si ◽  
Yu Wei ◽  
Yongbo Li
Keyword(s):  
Time Delay ◽  
Parameter Selection ◽  
Permutation Entropy ◽  
Embedding Dimension ◽  
Optimization Strategy ◽  
Extraction Ability ◽  
Dynamic Changes ◽  
Multi Scale ◽  
Simulated Signal ◽  
Selection Of

Multi-scale permutation entropy (MPE) is a statistic indicator to detect nonlinear dynamic changes in time series, which has merits of high calculation efficiency, good robust ability, and independence from prior knowledge, etc. However, the performance of MPE is dependent on the parameter selection of embedding dimension and time delay. To complete the automatic parameter selection of MPE, a novel parameter optimization strategy of MPE is proposed, namely optimized multi-scale permutation entropy (OMPE). In the OMPE method, an improved Cao method is proposed to adaptively select the embedding dimension. Meanwhile, the time delay is determined based on mutual information. To verify the effectiveness of OMPE method, a simulated signal and two experimental signals are used for validation. Results demonstrate that the proposed OMPE method has a better feature extraction ability comparing with existing MPE methods.

scholarly journals Multi‐scale approach for simulating time‐delay biochemical reaction systems

2015 ◽  
Vol 9 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Yuanling Niu ◽  
Kevin Burrage ◽  
Chengjian Zhang
Keyword(s):  
Time Delay ◽  
Biochemical Reaction ◽  
Reaction Systems ◽  
Multi Scale

Analytical solution and energy harvesting from nonlinear vibration of an asymmetric bimorph piezoelectric plate and optimizing the plate parameters by genetic algorithm

2017 ◽  
Vol 29 (6) ◽  
pp. 1120-1138 ◽  
Author(s):  
Hamed Shorakaei ◽  
Alireza Shooshtari
Keyword(s):  
Genetic Algorithm ◽  
Nonlinear Vibration ◽  
Piezoelectric Plate ◽  
Electrical Power ◽  
Electric Displacement ◽  
Primary Resonance ◽  
Load Resistance ◽  
Multiple Time Scales ◽  
Multiple Time ◽  
Piezoelectric Layers

In this article, harvesting of electrical power from nonlinear vibration of an asymmetric bimorph piezoelectric plate is presented based on the classical plate theory with von Kármán strain–displacement nonlinear relations in the presence of temperature change effect. Two piezoelectric layers with different thicknesses cover top and bottom layers of a substructure. The structure has been excited under harmonic transverse forces in case of primary resonance. Two coupled ordinary differential equations for displacement and voltage have been derived and solved via multiple time scales method. The voltage equation has been defined by electric displacement and Gauss’s law. Analytic relations for voltage and harvested electrical power have been derived. The analytic relation for power is based on different parameters of the plate such as thicknesses of the layers, dimensions of plate, load resistance, frequency of harmonic excitation, and mechanical properties of structure. The parameters are optimized using genetic algorithm method with consideration of power relation as cost function. To harvest the maximum energy from the plate, the thicknesses of two piezoelectric layers, load resistance, and detuning parameter have been optimized. To illustrate the effectiveness of the optimization, results are depicted in three different simulations.

scholarly journals Vertical Vibration Control of Cold Rolling Mill’s Rolls Based on Time-delay Feedback Control Method

2018 ◽  
Vol 153 ◽  
pp. 06005
Author(s):  
Dongxiao Hou
Keyword(s):  
Time Delay ◽  
Feedback Control ◽  
Cold Rolling ◽  
Rolling Mill ◽  
Control Method ◽  
Primary Resonance ◽  
Vertical Vibration ◽  
Resonance Amplitude ◽  
Feedback Control Method ◽  
Delay Feedback Control

In this paper, a two degree of freedom nonlinear vertical vibration equation of the cold rolling mill with the dynamic rolling force was established, then the delay feedback control method was introduced into the equation to controlled the vertical vibration of the system. The amplitude-frequency equations of primary resonance of system was carried out by using the multi-scale method, and the resonance characteristics of different parameters of delay feedback control method were obtained by adopting the actual parameters of rolling mill. It is found that the size of the resonance amplitude value was effectively controlled and the resonance region and jumping phenomenon of the system were eliminated by selecting the appropriate time-delay parameters combination, which provides an effective theoretical reference for solving mill vibration problems.

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