Nonlinear Dynamic Characteristics of PZT/Polymer Gripper

2018 ◽  
Vol 26 (1) ◽  
pp. 79-84
Author(s):  
Jia Xu ◽  
Yi-Ran Li ◽  
Hai-Bo Wang ◽  
Zhi-Wen Zhu
Keyword(s):  
Dynamic Response ◽  
Nonlinear Dynamic ◽  
Noise Intensity ◽  
Resonance Phenomenon ◽  
Dynamical Response ◽  
Stochastic Noise ◽  
Nonlinear Dynamic Model ◽  
Bounded Noise ◽  
Response Range ◽  
Nonlinear Dynamic Characteristics

A kind of PZT/polymer gripper is proposed in this paper and its nonlinear dynamic response in bounded noise is described. In this paper, a polymer piezoelectric material is applied in gripper to substitute the traditional PZT to improve the response range. Nonlinear differential items are introduced to interpret the hysteretic phenomena of the PZT/polymer piezoelectric composites material, and the nonlinear dynamic model of the PZT/polymer gripper in bounded noise is developed. The dynamic response of the system is obtained, and the bifurcation characteristics of the system are analyzed. The results of numerical simulation and experiments show that the stochastic noise intensity has important influence on the system's dynamical response, and the stochastic resonance phenomenon occurs with the stochastic noise intensity variety.

scholarly journals Nonlinear dynamic characteristics of SMA gripper under bounded noise

2019 ◽  
Vol 83 ◽  
pp. 01010
Author(s):  
Xin-Miao Li ◽  
Zhi-Wen Zhu ◽  
Qing-Xin Zhang
Keyword(s):  
Constitutive Model ◽  
Dynamic Response ◽  
Dynamic Model ◽  
Dynamic Characteristics ◽  
Nonlinear Dynamic ◽  
Vibration Amplitude ◽  
Random Disturbance ◽  
Bounded Noise ◽  
Nonlinear Dynamic Response ◽  
Nonlinear Dynamic Characteristics

A kind of constitutive model of SMA is proposed in this paper, and the nonlinear dynamic response of a SMA gripper under bounded noise is studied. The harmonic driving signals and the random disturbance made up of bounded noise. The dynamic model of the system is established by Hamilton principle. The numerical and experimental results show that there is stochastic resonance in the system; the system’s vibration amplitude reaches the most when the outside excitation is moderate.

Bifurcation and Chaos of a Spur Gear Transmission System With Non-Uniform Wear

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Zhibo Geng ◽  
Ke Xiao ◽  
Junyang Li ◽  
Jiaxu Wang
Keyword(s):  
Dynamic Model ◽  
Dynamic Characteristics ◽  
Nonlinear Dynamic ◽  
Operating Time ◽  
Spur Gear ◽  
Gear Transmission ◽  
Nonlinear Dynamic Model ◽  
Gear Backlash ◽  
Gear Transmission System ◽  
Nonlinear Dynamic Characteristics

Abstract In this study, a nonlinear dynamic model of a spur gear transmission system with non-uniform wear is proposed to analyze the interaction between surface wear and nonlinear dynamic characteristics. A quasi-static non-uniform wear model is presented, with consideration of the effects of operating time on mesh stiffness and gear backlash. Furthermore, a nonlinear dynamic model with six degrees-of-freedom is established considering surface friction, time-varying gear backlash, time-varying mesh stiffness, and eccentricity, and the Runge–Kutta method applied to solve this model. The bifurcation and chaos in the proposed dynamic model with the change of the operating time and the excitation frequency are investigated by bifurcation and spectrum waterfall diagrams to analyze the bifurcation characteristics and the dimensionless mesh force. It is found that surface wear is generated with a change in operating time and affects the nonlinear dynamic characteristics of the spur gear system. This study provides a better understanding of nonlinear dynamic characteristics of gear transmission systems operating under actual conditions.

The Gap Nonlinear Characteristics of Gear Transmission System under External Excitation

2012 ◽  
Vol 215-216 ◽  
pp. 1067-1070
Author(s):  
Kang Huang ◽  
Jue Li ◽  
Xin Jin ◽  
Qi Chen
Keyword(s):  
Dynamic Characteristics ◽  
Nonlinear Dynamic ◽  
Degrees Of Freedom ◽  
Transmission System ◽  
Gear Transmission ◽  
Engineering Practice ◽  
Nonlinear Dynamic Model ◽  
Gear Transmission System ◽  
Nonlinear Dynamic Characteristics ◽  
Domain Of Parameters

For the study of nonlinear dynamic characteristics of a pair of gears in an external torque under gear meshing error excitation, we will establish two degrees of freedom nonlinear torsional vibration model. The use of Matlab / Simulink for numerical simulation solves the nonlinear dynamic model of the gear gap. Study the dynamic characteristics of the system in a certain domain of parameters on external incentive conditions, as well as external motivation of gear transmission system dynamic characteristics influence. The results have important practical value for future engineering practice on gear transmission system's dynamic design, and have important theoretical significance for complex gear transmission system dynamics study.

scholarly journals Nonlinear Dynamics and Analysis of a Planar Multilink Complex Mechanism with Clearance

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Xiulong Chen ◽  
Shuai Jiang ◽  
Yu Deng ◽  
Qing Wang
Keyword(s):  
Nonlinear Dynamics ◽  
Dynamic Response ◽  
Phase Diagrams ◽  
Dynamic Model ◽  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
Lagrange Equation ◽  
Nonlinear Dynamic Model ◽  
Planar Mechanism ◽  
Driving Speed

In order to understand the nonlinear dynamic behavior of a planar mechanism with clearance, the nonlinear dynamic model of the 2-DOF nine-bar mechanism with a revolute clearance is proposed; the dynamic response, phase diagrams, Poincaré portraits, and largest Lyapunov exponents (LLEs) of mechanism are investigated. The nonlinear dynamic model of 2-DOF nine-bar mechanism containing a revolute clearance is established by using the Lagrange equation. Dynamic response of the slider’s kinematics characteristic, contact force, driving torque, shaft center trajectory, and the penetration depth for 2-DOF nine-bar mechanism are all analyzed. Chaos phenomenon existed in the mechanism has been identified by using the phase diagrams, the Poincaré portraits, and LLEs. The effects of the different clearance sizes, different friction coefficients, and different driving speeds on dynamic behavior are studied. Bifurcation diagrams with changing clearance value, friction coefficient, and driving speed are drawn. The research could provide important technical support and theoretical basis for the further study of the nonlinear dynamics of planar mechanism.

Involute spline couplings in aero-engine: Predicting nonlinear dynamic response with mass eccentricity

2021 ◽  
Vol 235 (1) ◽  
pp. 75-92
Author(s):  
Xiangzhen Xue ◽  
Qixin Huo ◽  
Karl D Dearn ◽  
Jian Liu ◽  
Jipeng Jia
Keyword(s):  
Dynamic Response ◽  
Nonlinear Dynamic ◽  
Power Transmission ◽  
Reference Model ◽  
Nonlinear Dynamic Model ◽  
Nonlinear Dynamic Response ◽  
Mass Eccentricity ◽  
Spline Coupling ◽  
Aero Engines ◽  
Involute Spline

This work presents a nonlinear dynamic model considering the multi-tooth meshing behaviour and mass eccentricity of an involute spline coupling to tackle the serious problem of involute spline failure, in aviation power transmission systems. The dynamic meshing force is calculated for the same. Based on this, the influence of different mass eccentricities on the nonlinear dynamic response of the spline coupling was investigated in aero-engines. The results show that when the mass eccentricity is small, its impact on the system is insignificant. When the eccentricity reaches a certain value, the quasi-periodic and chaotic state appears alternately. Meanwhile, it can be concluded that the acceleration-frequency spectrum during the multi-periodic phase is an approximation of the working frequency with the accuracy affected by multiple teeth engagements. This was validated by the vibration experiments of the involute spline coupling. The proposed model, which considers the multi-tooth meshing behaviour and the mass eccentricity provides a reference model for the dynamic analysis of similar structures. The nonlinear dynamic response results attained lay a good theoretical foundation for fretting damage analysis and precise designs for involute spline couplings.

Optimal Cable Configurations for Passive Dynamic Control of Compliant Towers

1984 ◽  
Vol 106 (4) ◽  
pp. 311-318 ◽  
Author(s):  
J. F. Wilson ◽  
G. Orgill
Keyword(s):  
Dynamic Response ◽  
Optimization Algorithm ◽  
Nonlinear Dynamic ◽  
Wind Wave ◽  
Dynamic Control ◽  
Nonlinear Dynamic Model ◽  
Human Comfort ◽  
Compatible System ◽  
Compliant Tower ◽  
The Ideal

Whether in storm or normal seas, the ideal offshore cable-stayed compliant tower moves in harmony with the wind and waves. A properly tuned cable configuration is the key to controlled dynamic response. Formulated here are a nonlinear dynamic model involving wind, wave, current, tower, and cable interactions and a cable optimization algorithm. The objective function, the rms tower rotation, is minimized subject to appropriate constraints involving compatible system geometries and loads, as well as bounds on the platform level accelerations needed for human comfort. Tower motion is limited to a plane.

Nonlinear dynamics analysis of rotor-brush seal system

2019 ◽  
Vol 43 (2) ◽  
pp. 209-220 ◽  
Author(s):  
Yuan Wei ◽  
Shulin Liu
Keyword(s):  
Nonlinear Dynamic ◽  
Vibration Amplitude ◽  
Time History ◽  
Force Model ◽  
Nonlinear Dynamic Model ◽  
Nonlinear Characteristics ◽  
Brush Seal ◽  
Nonlinear Dynamic Characteristics ◽  
Axis Orbit ◽  
Rotor Mass

When a gas turbine is working under high temperature, high pressure, and high velocity conditions, complex dynamic behavior and faults arise. These can seriously affect the security and reliability of the system, so it is important to further study nonlinear dynamic characteristics of the rotor-seal system. The seal force model of a brush seal was proposed, considering the interactions among bristle pack, flow force, and rotor, and a nonlinear dynamic model of the rotor-seal system was established. The influences of different geometries and operation parameters, such as rotor speed, installation spacing, damping, and rotor mass on the nonlinear characteristics of the system were discussed. The bifurcation scenario, vibration response, and stability of the rotor-seal system were analyzed by bifurcation diagram, time history, axis orbit, phase portrait, phase trajectory, Poincaré map, and frequency spectrum. The results showed that with a seal force the critical speed was greater than that without seal force conditions. The vibration amplitude of the rotor decreased with increase of damping and installation spacing. When the mass of the rotor increased, the vibration amplitude decreased significantly, which added stability to the rotor.

Nonlinear Dynamic Characteristics of Semi-Active Suspension System with SMA Spring Based on Hysteretic Nonlinear Theory

2010 ◽  
Vol 458 ◽  
pp. 265-270 ◽  
Author(s):  
Zhi Wen Zhu ◽  
Chang Wei Sui ◽  
Jia Xu
Keyword(s):  
Dynamic Characteristics ◽  
Nonlinear Theory ◽  
Nonlinear Dynamic ◽  
Qualitative Change ◽  
Active Suspension ◽  
Nonlinear Damping ◽  
Suspension System ◽  
Nonlinear Dynamic Model ◽  
Nonlinear Dynamic Characteristics ◽  
Sma Spring

In this paper, the nonlinear dynamic characteristics of vehicle semi-active suspension system with SMA spring were studied in hysteretic nonlinear theory. SMA spring was applied in semi-active suspension system to control vibration. Von del Pol hysteretic cycle model were introduced to set up a new kind of continuous SMA strain-stress model, based on which the nonlinear dynamic model of vehicle semi-active suspension system with SMA spring was developed. The first-order nonlinear approximate solution of suspension system was obtained, the stability and bifurcation characteristic of suspension system were analyzed. The result of analysis shows that the nonlinear stiffness parameters can not cause the bifurcation of suspension system, and the qualitative change of the dynamic characteristic of suspension system has relationship with the nonlinear damping parameters. Finally, the result of analysis was proved by simulation.

Nonlinear dynamic characteristics and optimal control of MSMA actuator subjected to harmonic magnetic field and stochastic excitation

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1523-1529
Author(s):  
Benhy Ngouala ◽  
Fang Liu ◽  
Jia Xu ◽  
Zhi-Wen Zhu
Keyword(s):  
Magnetic Field ◽  
Dynamic Programming ◽  
Dynamic Response ◽  
Dynamic Characteristics ◽  
Nonlinear Dynamic ◽  
Stochastic Perturbation ◽  
Stochastic Dynamic ◽  
Random Disturbance ◽  
Magnetic Shape Memory ◽  
Nonlinear Dynamic Characteristics

A novel magnetic shape memory alloy (MSMA) actuator is proposed in this paper, which has fast response speed and large deformation, and its nonlinear dynamic response and control are studied. A new differential term is developed to explain the MSMA’s stress-strain curves. The dynamic model of the MSMA actuator subjected to harmonic magnetic field and random disturbance is established, and its nonlinear dynamic characteristics are obtained. Finally, the stochastic dynamic programming control is introduced to enhance the drive accuracy. The results show that the perturbation plays an important role in the system’s dynamic response; dynamic programming control can improve the actuator’s accuracy in strong stochastic perturbation. These results will be helpful for the optimal design and development of MSMA actuators.

Complexity evaluation of nonlinear dynamic behavior of mechanisms with clearance joints by using the fractal method

2014 ◽  
Vol 228 (18) ◽  
pp. 3482-3495 ◽  
Author(s):  
Wuweikai Xiang ◽  
Shaoze Yan ◽  
Jianing Wu ◽  
Robert X Gao
Keyword(s):  
Dynamic Response ◽  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
Correlation Dimension ◽  
Nonlinear Dynamic Response ◽  
Fractal Method ◽  
Motion Equations ◽  
Clearance Joints ◽  
Nonlinear Dynamic Characteristics ◽  
Crank Mechanism

Dynamic behavior of mechanisms with clearance joints often exhibits nonlinear dynamic characteristics due to the collisions between the journal and bearing. However, previous studies could not quantify the complexity of the dynamic response. In this paper, based on the Poincaré map and correlation dimension, a fractal method is proposed to evaluate the complexity of nonlinear dynamic response of mechanisms with clearance joints. Motion equations of mechanical systems with clearance joints are described. A slider–crank mechanism is employed to demonstrate the efficiency of the fractal method and to discuss the influence of the clearance size and crank speed on the complexity of the dynamic response.

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