scholarly journals A nonlinear dynamic model of magnetorheological elastomers in magnetic fields based on fractional viscoelasticity

2020 ◽  
pp. 1045389X2095361
Author(s):  
Guanghong Zhu ◽  
Yeping Xiong ◽  
Zigang Li ◽  
Ling Xiao ◽  
Ming Li ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Experimental Results ◽  
Model Parameters ◽  
Nonlinear Dynamic Model ◽  
Dynamic Moduli ◽  
Magnetorheological Elastomers ◽  
Proposed Model ◽  
Wide Range

As smart materials, magnetorheological elastomers (MREs) have been broadly applied in the field of intelligent structures and devices. In order to mathematically represent the dynamic behavior in a wide range of strain amplitude, excitation frequency and magnetic field; a nonlinear model with a fractional element was developed for MREs in a linear viscoelastic regime. The identification of model parameters was realized through fitting experimental data of dynamic moduli measured in shear mode, and the identified parameters exhibited good repeatability and consistency to reflect the rationality of this nonlinear dynamic model. Considering material elasticity and viscosity, the dependence of model parameters on strain amplitudes and magnetic fields was analyzed to interpret the dynamics of MREs. The fitted results displayed an excellent agreement with the experimental results on the dependence of dynamic moduli on strain amplitudes and magnetic fields. Using the predictor-corrector approach, predicted results on the stress-strain hysteresis loop were calculated based on identified parameters to further validate the proposed model by comparing with experimental results and predicted results of the revised Bouc-Wen model. This proposed model is expected to facilitate the dynamic analysis and simulation of MRE based vibration systems with a high precision accuracy.

Nonlinear Dynamic Model of a Two-Stage Pressure Relief Valve for Designers

2001 ◽  
Vol 124 (1) ◽  
pp. 62-66 ◽  
Author(s):  
Pei-Sun Zung ◽  
Ming-Hwei Perng
Keyword(s):  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Dynamic Models ◽  
Operating Conditions ◽  
Model Parameters ◽  
Nonlinear Dynamic Model ◽  
Relief Valve ◽  
Two Stage ◽  
Pressure Relief ◽  
Wide Range

This paper presents a handy nonlinear dynamic model for the design of a two stage pilot pressure relief servo-valve. Previous surveys indicate that the performance of existing control valves has been limited by the lack of an accurate dynamic model. However, most of the existing dynamic models of pressure relief valves are developed for the selection of a suitable valve for a hydraulic system, and assume model parameters which are not directly controllable during the manufacturing process. As a result, such models are less useful for a manufacturer eager to improve the performance of a pressure valve. In contrast, model parameters in the present approach have been limited to dimensions measurable from the blue prints of the valve such that a specific design can be evaluated by simulation before actually manufacturing the valve. Moreover, the resultant model shows excellent agreement with experiments in a wide range of operating conditions.

Dynamic Simulation of Large Flow Solenoid Valve

2016 ◽  
Author(s):  
Z. Liu ◽  
X. Han ◽  
Y. F. Liu
Keyword(s):  
Dynamic Model ◽  
Dynamic Simulation ◽  
Dynamic Characteristics ◽  
Nonlinear Dynamic ◽  
Structural Parameters ◽  
Solenoid Valve ◽  
Simulation Software ◽  
Experimental Results ◽  
Nonlinear Dynamic Model ◽  
Large Flow

A nonlinear dynamic model of a large flow solenoid is presented with the multi-physics dynamic simulation software called SimulationX. Validation is performed by comparing the experimental results with the simulated ones. The dynamic characteristics of the large flow solenoid valve are analyzed. Different structural parameters are modified in this research and the diameter of the orifice is proved to be one of the most important parameters which influences the pressure response most.

Mathematical Modeling of a Two Spool Flow Control Servovalve Using a Pressure Control Pilot1

2002 ◽  
Vol 124 (3) ◽  
pp. 420-427 ◽  
Author(s):  
Randall T. Anderson ◽  
Perry Y. Li
Keyword(s):  
Mathematical Modeling ◽  
Flow Control ◽  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Pressure Control ◽  
Dynamic Effects ◽  
Nonlinear Dynamic Model ◽  
Two Stage ◽  
Matlab Simulink ◽  
Proposed Model

A nonlinear dynamic model for an unconventional, commercially available electrohydraulic flow control servovalve is presented. The two stage valve differs from the conventional servovalve design in that: it uses a pressure control pilot stage; the boost stage uses two spools, instead of a single spool, to meter flow into and out of the valve separately; and it does not require a feedback wire and ball. Consequently, the valve is significantly less expensive. The proposed model captures the nonlinear and dynamic effects. The model has been coded in Matlab/Simulink and experimentally validated.

Mathematical Modeling of a Two Spool Flow Control Servovalve Using a Pressure Control Pilot

2000 ◽  
Author(s):  
Randy T. Anderson ◽  
Perry Y. Li
Keyword(s):  
Mathematical Modeling ◽  
Flow Control ◽  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Pressure Control ◽  
Dynamic Effects ◽  
Nonlinear Dynamic Model ◽  
Two Stage ◽  
Proposed Model

Abstract A nonlinear dynamic model for an unconventional, commercially available electrohydraulic flow control servovalve is presented. The valve is a two-stage valve and differs from the conventional servovalve in that it does not require a feedback wire and ball, and the boost stage uses two spools, instead of a single spool, to meter flow into and out of the valve separately. Consequently, the valve is significantly less expensive. The proposed model captures the nonlinear and dynamic effects not present in previous models. The model has been coded in Simulink and experimentally validated.

scholarly journals Real-Time Disturbances Estimating and Compensating of Nonlinear Dynamic Model for Underwater Vehicles

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Yuexin Zhang ◽  
Lihui Wang
Keyword(s):  
Kalman Filter ◽  
Dynamic Model ◽  
Navigation System ◽  
Nonlinear Dynamic ◽  
Model Parameters ◽  
System State ◽  
Nonlinear Dynamic Model ◽  
External Disturbances ◽  
Cubature Kalman Filter ◽  
Nonlinear Disturbances

To reduce the deviation caused by the stochastic environmental disturbances, estimating these disturbances is required to compensate the navigation system. Based on the idea of Kalman filter using least-squares algorithm for optimal estimation, a nonlinear disturbances estimator which can be perfectly integrated with cubature Kalman filter (CKF) is proposed. For the nonlinear disturbances estimator, the disturbances are estimated by gain matrix, innovation sequences, and innovation covariance generated by CKF. The disturbances estimating and compensating algorithm consists of three parts. Firstly, the navigation system state space model is established based on nonlinear dynamic model of six degrees of freedom. Secondly, the external disturbances are estimated by using CKF and a nonlinear estimator. Finally, the disturbances compensation is carried out by improving the system state equation. In view of the uncertainty of the dynamic model and the randomness of external disturbances, numerical simulation experiments are conducted in the circumstances of sinusoidal disturbances, random disturbances, and uncertain model parameters. The results demonstrate that the proposed method can estimate disturbances effectively and improves navigation accuracy significantly.

Development and validation of a simplified nonlinear dynamic model of a passive twin-tube hydraulic shock absorber

2020 ◽  
pp. 107754632094795
Author(s):  
Verónica Santos Arconada ◽  
Jon García-Barruetabeña
Keyword(s):  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Shock Absorber ◽  
Driving Simulator ◽  
Ride Comfort ◽  
Hydraulic Shock ◽  
Nonlinear Dynamic Model ◽  
Proposed Model ◽  
Hydraulic Shock Absorber ◽  
Development And Validation

In this study, the development and validation of a simplified nonlinear dynamic model of a passive twin-tube hydraulic shock absorber is presented. First, the experimental dynamic response is characterized. Then, the numerical model is presented where flow, pressure, displacement, and velocity are considered. Finally, the numerical–experimental correlation is performed on force-movement dynamic behavior to prove the accuracy of the proposed model. The final goal of the model is to be integrated in a real-time driving simulator for ride comfort studies.

Analysis of Tourism Ecology Capacity Based on the Nonlinear Dynamic Model

2009 ◽  
Vol 11 (2) ◽  
pp. 163-168
Author(s):  
Long LV ◽  
Zhenfang HUANG ◽  
Jiang WU
Keyword(s):  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Model
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