Nonlinear Model and Simulation Experiment Research of Vibratory Rollers

2011 ◽  
Vol 121-126 ◽  
pp. 2121-2125
Author(s):  
Yuan Hao ◽  
Zhao Hui Ren ◽  
Feng Wen
Keyword(s):  
Nonlinear Vibration ◽  
Simulation Experiment ◽  
Response Characteristic ◽  
Soil Mass ◽  
System Model ◽  
System Response ◽  
Experiment Research ◽  
System Parameters ◽  
Model And Simulation ◽  
Excitation Force

On the basis of the relation between force and deformation when the plastic deformation of soil mass is studied, nonlinear vibration roller model is built. Based on one type vibratory rollers select the system parameters and calculate the natural frequency. And according to the selected numerical value proceed the numerical simulation with different excitation force frequencies. Meanwhile, obtain and analyze the experimental data according to the vibratory roller experiment. Then the system response characteristic of nonlinear vibration roller is obtained, and the availability of system model is checked. All above provide the valuable theoretical basis for the research of vibrating compacting.

Identification of System Parameters of Slab Vibrated With Vibrator by Using Wavelet Transform

2005 ◽  
Author(s):  
Naoto Imanishi ◽  
Akira Sone ◽  
Arata Masuda
Keyword(s):  
Wavelet Transform ◽  
Health Monitoring ◽  
Maintenance Management ◽  
Spring Constant ◽  
System Model ◽  
Mass System ◽  
System Parameters ◽  
Noisy Conditions ◽  
Excitation Force ◽  
Spring Constants

In health monitoring of slabs of a road bridge, it is suitable to carry out on the basis of their stiffness, which is evaluated by spring constants of a spring-mass system model of the slab. When the value of the spring constant is known, the rigidity of the slab and the deflection against the predetermined load can be estimated. These can be used as the basic data of maintenance management of them. The authors have been proposing the method to identify the spring constant of the slab by wavelet transform of an excitation force and acceleration responses. In this paper, the method to identify the spring constants of slabs is theoretically investigated under the noisy conditions. The method to find the specific values of constant α in an analyzing wavelet by which the most reliable value of the spring constant is given according to the graphic form showing the relation between identified mass and constant α.

Dynamic Model and Simulation of Flag Vibrations Modeled as a Membrane

2014 ◽  
Author(s):  
Gary Frey ◽  
Ben Carmichael ◽  
Joshua Kavanaugh ◽  
S. Nima Mahmoodi
Keyword(s):  
Constant Velocity ◽  
Cross Flow ◽  
Vertical Direction ◽  
Equation Of Motion ◽  
Mode Shapes ◽  
System Response ◽  
Wind Flow ◽  
Pressure Function ◽  
Model And Simulation ◽  
Reasonable Model

A flag is modeled as a membrane to investigate the two-dimensional characteristics of the vibration response to an uniform wind flow. Both the affecting tension and pressure functions for the wind flow with constant velocity are introduced and utilized in the modeling. In this case, the tension is caused by the weight of the flag. The pressure function is a function describing the pressure variations caused on the flag when in uniform flow. The pressure function is found by assuming that the air flow is relatively slow and that the flag is wide enough to minimize cross flow at the boundaries. An analysis of the downstream motion of the flag is necessary as well. Hamilton’s principle is employed to derive the partial differential equation of motion. The flag is oriented in the vertical direction to neglect the effect of the flag’s weight on the system’s response. Galerkin’s method is used to solve for the first four mode shapes of the system, and the system response is numerically solved. Simulations reveal a very reasonable model when the flag is modeled as a membrane.

scholarly journals Comparative Analysis of Polarimetric SAR Calibration Methods

2018 ◽  
Vol 10 (12) ◽  
pp. 2060 ◽  
Author(s):  
Yoon Jung ◽  
Sang-Eun Park
Keyword(s):  
Comparative Analysis ◽  
Calibration Method ◽  
System Model ◽  
Synthetic Aperture ◽  
Polarimetric Sar ◽  
Alos Palsar ◽  
Polarimetric Synthetic Aperture Radar ◽  
System Parameters ◽  
Calibration Methods ◽  
Polarimetric Calibration

In the diverse applications of polarimetric Synthetic Aperture Radar (SAR) systems, it is a crucial to conduct polarimetric calibration, which aims to remove the radar system distortion effects prior to utilizing polarimetric SAR observations. The objective of this study is to evaluate the performance of different polarimetric calibration methods. Two widely used methods, the Van Zyl and Quegan methods, and one recently proposed method, such as the Villa method, have been selected among various calibration methods in literature. The selected methods have basic differences in their assumptions that are applied to the polarimetric system model. In order to evaluate the calibration performances under different system parameters and ground characteristics, comparative analysis of the calibration results were conducted on synthetic polarimetric SAR data and ALOS PALSAR quad-pol mode data. Based on the experimental results, the advantages and limitations of different methods were clarified, and a simple hybrid calibration method is presented to further improve the polarimetric calibration performance.

scholarly journals Research on Chaos Response of the Nonlinear Vibration System of Giant Magnetostrictive Actuator

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Hongbo Yan ◽  
Yu Niu ◽  
Hong Gao ◽  
Hongbo Hao
Keyword(s):  
Mathematical Model ◽  
Amplitude Spectrum ◽  
Experimental Simulation ◽  
System Response ◽  
Threshold Condition ◽  
Vibration System ◽  
Chaotic Response ◽  
Magnetostrictive Actuator ◽  
Excitation Force ◽  
The Mathematical Model

In the present study, the chaotic response of the nonlinear magnetostrictive actuator (GMA) vibration system is investigated. The mathematical model of the nonlinear GMA vibration system is established according to J-A hysteresis nonlinear model, quadratic domain rotation model, Newton’s third law, and principle of GMA structural dynamics by analyzing the working principle of GMA. Then, the Melnikov function method is applied to the threshold condition of the chaotic response of the system to obtain the sense of Smale horseshoe transformation. Furthermore, the mathematical model is solved to investigate the system response to the excitation force and frequency. Accordingly, the corresponding displacement waveform, phase plane trajectory, Poincaré map, and amplitude spectrum are obtained. The experimental simulation is verified using Adams software. The obtained results show that the vibration equation of the nonlinear GMA vibration system has nonlinear and complex motion characteristics with different motion patterns. It is found that the vibration characteristics of the system can be controlled through adjusting the excitation force and frequency.

Gas Storage Cavity Simulation Experiment Research and Application

2014 ◽  
Vol 496-500 ◽  
pp. 891-895
Author(s):  
Ji Fang Wan ◽  
Rui Chen Shen ◽  
Zhong Yuan Ji ◽  
Jing Bin Xie
Keyword(s):  
Simulation Experiment ◽  
Gas Storage ◽  
Salt Rock ◽  
Experiment Research ◽  
Solution Mining ◽  
Drill Site ◽  
Similarity Ratio ◽  
Rock Model ◽  
Salt Caverns ◽  
The Mathematical Model

The real salt cores from drill-site was regarded as the prototype in this experiment. They are used to simulate solution mining process of salt caverns. In this paper the mathematical model of solution mining wasset up.Experimental parameters are obtained by similarity ratio. Afternumerous experiments on the artificial salt rock model,the results show that thecontrol experimental parametersand the references design are effective.This researchhas some guidance on field engineering of solution mining construction.

Numerical Investigation of Nonlinear Dynamics of a Pneumatic Artificial Muscle With Hard Excitation

2020 ◽  
Vol 15 (4) ◽  
Author(s):  
Bhaben Kalita ◽  
Santosha K. Dwivedy
Keyword(s):  
Nonlinear Dynamics ◽  
Resonance Condition ◽  
Basin Of Attraction ◽  
Artificial Muscle ◽  
Phase Portraits ◽  
System Response ◽  
Pneumatic Artificial Muscle ◽  
Superharmonic Resonance ◽  
System Parameters ◽  
Hard Excitation

Abstract In this work, a numerical analysis has been carried out to study the nonlinear dynamics of a system with pneumatic artificial muscle (PAM). The system is modeled as a single degree-of-freedom system and the governing nonlinear equation of motion has been derived to study the various responses of the system. The system is subjected to hard excitation and hence the subharmonic and superharmonic resonance conditions have been studied. The second-order method of multiple scales (MMS) has been used to find the response, stability, and bifurcations of the system. The effect of various system parameters on the system response has been studied using time response, phase portraits, and basin of attraction. In these responses, while the saddle node bifurcation is found in both super and subharmonic resonance conditions, the Hopf bifurcation is found only in superharmonic resonance condition. By changing different system parameters, it has been shown that the response with three periods leads to chaotic response for superharmonic resonance condition. This study will find applications in the design of PAM actuators.

Comparative Study of Evolutionary Algorithms for Parameter Identification of an Impact Oscillator

2014 ◽  
Author(s):  
Amit Banerjee ◽  
Issam Abu Mahfouz
Keyword(s):  
Evolutionary Algorithms ◽  
Differential Evolution ◽  
Parameter Identification ◽  
Optimization Techniques ◽  
System Response ◽  
Impact Oscillator ◽  
Swarm Optimization ◽  
System Parameters ◽  
Highly Nonlinear ◽  
The Impact

The use of non-classical evolutionary optimization techniques such as genetic algorithms, differential evolution, swarm optimization and genetic programming to solve the inverse problem of parameter identification of dynamical systems leading to chaotic states has been gaining popularity in recent years. In this paper, three popular evolutionary algorithms — differential evolution, particle swarm optimization and the firefly algorithm are used for parameter identification of a clearance-coupled-impact oscillator system. The behavior of impacting systems is highly nonlinear exhibiting a myriad of harmonic, low order and high order sub-harmonic resonances, as well as chaotic vibrations. The time-history simulations of the single-degree-of-freedom impact oscillator were obtained by the Neumark-β numerical integration algorithm. The results are illustrated by bifurcation graphs, state space portraits and Poincare’ maps which gives valuable insights on the dynamics of the impact system. The parameter identification problem relates to finding one set of system parameters given a chaotic or periodic system response as a set of Poincaré points and a different but known set of system parameters. The three evolutionary algorithms are compared over a set of parameter identification problems. The algorithms are compared based on solution quality to evaluate the efficacy of using one algorithm over another.

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