A Reduced-Order Dynamic Model of Nonlinear Oscillating Devices

2007 ◽  
Vol 129 (4) ◽  
pp. 514-521
Author(s):  
R. Xu ◽  
K. Komvopoulos
Keyword(s):  
Dynamic Model ◽  
Driving Force ◽  
Nonlinear Response ◽  
Rotation Angle ◽  
Damping Ratio ◽  
Nonlinear Behavior ◽  
Nonlinear Stiffness ◽  
Reduced Order ◽  
Simulation Results ◽  
Nonlinear Devices

A reduced-order dynamic model is presented for nonlinear devices subjected to in-plane oscillatory motion. Comparisons between numerical and finite element results demonstrate that the nonlinear behavior of a planar resonator can be predicted accurately by the derived dynamic model with significantly less computation. Simulation results illustrate the effects of nonlinear stiffness, damping ratio, electrostatic driving force, and device dimensions on the nonlinear dynamic behavior. The analysis yields two possible stable responses, depending on the initial rotation angle and rotation rate. The present dynamic model can be easily modified to analyze the nonlinear response of various planar resonators.

A Study of Wheel Flange Partial Wear Problem of Heavy Haul Locomotive

2011 ◽  
Vol 204-210 ◽  
pp. 241-244 ◽  
Author(s):  
Wei Hua Ma ◽  
Shi Hui Luo ◽  
Rong Rong Song
Keyword(s):  
Dynamic Model ◽  
Rotation Angle ◽  
Dynamic Performance ◽  
Lateral Force ◽  
Buffer System ◽  
Heavy Haul Train ◽  
Force Transfer ◽  
Heavy Haul ◽  
Brake Force ◽  
Simulation Results

Aimed to wheel flange partial wear problem, the heavy haul train dynamic model was setup, and the coupler and buffer system was setup in detail. The dynamic performance of the train under the longitudinal coupler press force was simulated. The wheel/rail lateral force and wheel flange wear were analyses. Simulation results shown that the front locomotive will suffer a big longitudinal press force for the delay of the brake force transfer; this will lead the rotation of the coupler. The lateral force will apply to the car body at the position of coupler, which was caused by the longitudinal coupler force and the rotation angle of the coupler, then the wheel flange partial wear were induced as a result.

Simulation of Singly and Doubly Clamped Nanotube Based NEMS Devices

2009 ◽  
Author(s):  
P. Chen ◽  
B. Peng ◽  
L. Ding ◽  
W. H. Xu ◽  
Y. Q. Wang ◽  
...  
Keyword(s):  
Nonlinear Deformation ◽  
Large Deformations ◽  
Nonlinear Behavior ◽  
Reduced Order Modeling ◽  
Multiphysics Simulation ◽  
Reduced Order ◽  
Theoretical Predictions ◽  
Simulation Results ◽  
Novel Devices ◽  
Insight Into

In this paper a multiphysics simulation of nanotube based nano-electromechanical systems is reported. Assuming continuum mechanics, the nonlinear deformation of the nanotube is simulated using reduced order modeling method. In particular, we study singly and doubly clamped nanotubes under electrostatic actuation. The simulation emphasizes the prediction of the pull-in voltage of the device, a key design parameter. Moreover, the nonlinear behavior associated with finite kinematics (i.e., large deformations), neglected in previous studies, are investigated in detail. The multiphysics simulation results agree well with the theoretical predictions verifying that the numerical model is valid. The results show that nonlinear kinematics results in an important increase in the pull-in voltage of doubly clamped nanotube devices, but that it is negligible in the case of singly clamped devices. These models provide a guide on the effect of the various geometrical variables and insight into the design of novel devices.

scholarly journals Analytical Model of Bolted Joint Structure and Its Nonlinear Dynamic Characteristics in Transient Excitation

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Xin Liao ◽  
Jianrun Zhang ◽  
Xiyan Xu
Keyword(s):  
Dynamic Response ◽  
Analytical Model ◽  
Nonlinear Behavior ◽  
Nonlinear Effects ◽  
Tangential Direction ◽  
Nonlinear Stiffness ◽  
Bolted Joint ◽  
Element Analysis ◽  
Simulation Results ◽  
Cubic Stiffness

The dynamic response of crucial components often depends upon the dynamic behavior of bolted connections. As is usually the case, the accurate modeling of structures with many mechanical joints remains a challenge work. The nonlinear behavior included in assembled structures strongly depends on the interface properties. In this paper, an analytical model of the simple bolted joint beam in tangential direction is first proposed for transient excitation, based on phenomenological model. The fourth-order Runge-Kutta method is employed to calculate the transient response, where the dynamic response of the nonlinear stiffness on system is also investigated. The simulation results show that natural frequency has a certain dependence on cubic stiffness term and cubic stiffness is more suitable for modeling of nonlinear system of a wider frequency range. Thereby, a series Iwan model containing cubic stiffness term is established to describe nonlinear behaviors of bolted joint beams in shear vibration. The amplitude-frequency curves show that the influence of interaction between nonlinear stiffness and damping mechanism on dynamic response characteristics is more obvious. Finally, a new type of nonlinear model is applied into finite element analysis. The results of proposed transient excitation experiment are discussed qualitatively, indicating that nonlinear effects observed agree with the numerical simulation results.

scholarly journals Research on Damping Characteristics of Interconnected Hydropneumatic Suspension considering the Effects of Hose and Check Valve

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Hongmin Zhang ◽  
Xin Fang
Keyword(s):  
Numerical Simulation ◽  
Energy Method ◽  
Damping Ratio ◽  
Check Valve ◽  
Nonlinear Stiffness ◽  
Calculation Formula ◽  
Damping Force ◽  
Damping Characteristics ◽  
Simulation Results ◽  
Stiffness And Damping

The interconnected hydropneumatic suspension (ICHPS) has not only the nonlinear stiffness and damping of the independent hydropneumatic suspension (IDHPS) but also antiroll and antipitch functions. The existing analysis of hydropneumatic suspension damping mainly focuses on the orifice and check valve in the suspension cylinder. In this study, the calculation formula of the damping force of ICHPS is established, and the numerical simulation results show that the damping characteristics of the hydraulic hose cannot be ignored. The influence of check valve and hose on the damping characteristics is analyzed. Through the equivalent energy method, the equivalent compression damping ratio and the equivalent recovery damping ratio of the ICHPS are established. It is pointed out that when designing the damping characteristics of the ICHPS, it is necessary to select the orifices, check valves, and hose damping reasonably to make the damping characteristics get the best match.

Intelligent Information of TS Fuzzy PID Control System of BLDCM

2013 ◽  
Vol 846-847 ◽  
pp. 313-316 ◽  
Author(s):  
Xiao Yun Zhang
Keyword(s):  
Control System ◽  
Dynamic Model ◽  
Pid Control ◽  
Control Method ◽  
Design Method ◽  
Fuzzy Pid ◽  
Fuzzy Pid Control ◽  
Control Precision ◽  
Simulation Results ◽  
Intelligent Information

This paper presented a new method based on the Fuzzy self - adaptive PID for BLDCM. This method overcomes some defects of the traditional PID control. Such as lower control precision and worse anti - jamming performance. It dynamic model of BLDCM was built, and then design method for TS fuzzy PID model is given, At last, it compared simulation results of PID control method with TS Fuzzy PID control method. The results show that the TS Fuzzy PID control method has more excellent dynamic antistatic performances, as well as anti-jamming performance. The experiment shows that TS fuzzy PID control has the stronger adaptability robustness and transplant.

Inverse Kinematic Solution and Dynamic Model to 3PTT Parallel Mechanism

2014 ◽  
Vol 945-949 ◽  
pp. 1421-1425
Author(s):  
Xiu Qing Hao
Keyword(s):  
Dynamic Model ◽  
Dynamic Simulation ◽  
Parallel Mechanism ◽  
Inverse Kinematic ◽  
Euler Method ◽  
Research Subject ◽  
Adams Software ◽  
Inverse Kinematic Analysis ◽  
Simulation Results ◽  
Kinematic Solution

Take typical parallel mechanism 3PTT as research subject, its inverse kinematic analysis solution was gotten. Dynamic model of the mechanism was established by Newton-Euler method, and the force and torque equations were derived. Dynamic simulation of 3PTT parallel mechanism was done by using ADAMS software, and simulation results have verified the correctness of the theoretical conclusions.

Study on the Steering Performance of Dual-Motor Drive Track Bulldozer

2013 ◽  
Vol 427-429 ◽  
pp. 133-136
Author(s):  
Qiang Song ◽  
Pu Zeng
Keyword(s):  
Simulation Model ◽  
Dynamic Characteristics ◽  
Driving Force ◽  
Driving Forces ◽  
Small Radius ◽  
Motor Drive ◽  
Matlab Simulink ◽  
Simulation Results ◽  
Two Sides

The driving theory and the dynamic characteristics of small radius steering, medium radius steering and big radius steering is analyzed, and the simulation model is established under Matlab/Simulink. Then the track bulldozers steering performance of the three sheerings is simulated. The results show that, at different steering modes, the running states of the two sides driving motors are not the same, and the track driving forces of the two sides vary widely. The track driving force is great in the small radius steering model, while small in the medium and big radius steering models. The simulation results lay the foundation for dual-motor drive track bulldozers steering performance matching.

Reduced Order Model of MEMS Sensors Near Natural Frequency

2011 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Jose C. Solis Silva
Keyword(s):  
Natural Frequency ◽  
Nonlinear Response ◽  
Casimir Effect ◽  
Electrostatic Force ◽  
Reduced Order Model ◽  
Mass Detection ◽  
Order Model ◽  
Reduced Order ◽  
First Order ◽  
Electrostatically Actuated

The nonlinear response of an electrostatically actuated cantilever beam microresonator sensor for mass detection is investigated. The excitation is near the natural frequency. A first order fringe correction of the electrostatic force, viscous damping, and Casimir effect are included in the model. The dynamics of the resonator is investigated using the Reduced Order Model (ROM) method, based on Galerkin procedure. Steady-state motions are found. Numerical results for uniform microresonators with mass deposition and without are reported.

A New Method to Find the Forced Response of Nonlinear Systems with Dry Friction

2021 ◽  
Author(s):  
Gregory L. Altamirano ◽  
Meng-Hsuan Tien ◽  
Kiran D'Souza
Keyword(s):  
Dry Friction ◽  
Coulomb Friction ◽  
Nonlinear Response ◽  
Piecewise Linear ◽  
Time Integration ◽  
Nonlinear Behavior ◽  
Forced Response ◽  
New Method ◽  
Analysis Tools ◽  
Compatibility Constraint

Abstract Coulomb friction has an influence on the behavior of numerous mechanical systems. Coulomb friction systems or dry friction systems are nonlinear in nature. This nonlinear behavior requires complex and time demanding analysis tools to capture the dynamics of these systems. Recently, efforts have been made to develop efficient analysis tools able to approximate the forced response of systems with dry friction. The objective of this paper is to introduce a methodology that assists in these efforts. In this method, the piecewise-linear nonlinear response is separated into individual linear responses that are coupled together through compatibility constraint equations. The new method is demonstrated on a number of systems of varying complexity. The results obtained by the new method are validated through the comparison with results obtained by time integration. The computational savings of the new method is also discussed.

A Physics-Based Dynamic Model for Boilers: Part 2 — Model Reduction in a Cogeneration Application

2017 ◽  
Author(s):  
Matthew J. Blom ◽  
Michael J. Brear ◽  
Chris G. Manzie ◽  
Ashley P. Wiese
Keyword(s):  
Model Reduction ◽  
Gas Turbine ◽  
Dynamic Model ◽  
Reduction Process ◽  
Singular Perturbation Theory ◽  
Reduced Order Models ◽  
Reduced Order ◽  
One Dimensional ◽  
Time Scale Separation ◽  
Modelling Framework

This paper is the second part of a two part study that develops, validates and integrates a one-dimensional, physics-based, dynamic boiler model. Part 1 of this study [1] extended and validated a particular modelling framework to boilers. This paper uses this framework to first present a higher order model of a gas turbine based cogeneration plant. The significant dynamics of the cogeneration system are then identified, corresponding to states in the gas path, the steam path, the gas turbine shaft, gas turbine wall temperatures and boiler wall temperatures. A model reduction process based on time scale separation and singular perturbation theory is then demonstrated. Three candidate reduced order models are identified using this model reduction process, and the simplest, acceptable dynamic model of this integrated plant is found to require retention of both the gas turbine and boiler wall temperature dynamics. Subsequent analysis of computation times for the original physics-based one-dimensional model and the candidate, reduced order models demonstrates that significantly faster than real time simulation is possible in all cases. Furthermore, with systematic replacement of the algebraic states with feedforward maps in the reduced order models, further computational savings of up to one order of magnitude can be achieved. This combination of model fidelity and computational tractability suggest suggests that the resulting reduced order models may be suitable for use in model based control of cogeneration plants.

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