Dynamic Response of a Cam-Actuated Mechanism With Pneumatic Coupling

1977 ◽  
Vol 99 (3) ◽  
pp. 598-603 ◽  
Author(s):  
F. Y. Chen
Keyword(s):  
Dynamic Response ◽  
Dynamic Characteristics ◽  
Lumped Parameter Model ◽  
System Equation ◽  
Variation Of Parameters ◽  
Lumped Parameter ◽  
Cam Follower ◽  
The Stability

The dynamic characteristics of a cam-actuated system whose follower mass is coupled with a nonlinear pneumatic mechanism of hysteretic type are investigated using a lumped-parameter model. The dynamic response of the cam follower is obtained from the solution of the formulated system equation by the Krylov-Bogoliubov method of variation of parameters. The stability of the system is also investigated.

Tuning the hygro-mechanical response of paper-based systems using glycerol

2020 ◽  
pp. 1045389X2094716
Author(s):  
Isaias Cueva-Perez ◽  
Roque Alfredo Osornio-Rios ◽  
Aurelio Dominguez-Gonzalez ◽  
Ion Stiharu ◽  
Angel Perez-Cruz
Keyword(s):  
Dynamic Response ◽  
Resonance Frequency ◽  
Mechanical Response ◽  
Water Solution ◽  
Low Cost ◽  
Mechanical Systems ◽  
Lumped Parameter Model ◽  
Glycerol Water ◽  
Energy Harvesters ◽  
Lumped Parameter

In recent years, the need for portable, low-cost, and eco-friendly devices for testing and monitoring has arisen. Paper-based devices have emerged as a response to these needs due to the properties induced by capillarity, flexibility, disposability, and biodegradability. In this work, the authors explored the possibility of tuning the hygro-mechanical response of paper-based cantilever beams using glycerol. A lumped-parameter model with non-linear stiffness is used to describe the dynamic response of the beams using three parameters. An experimental method based on resonance frequency tests is used to study the influence of glycerol on the dynamic response of four different beam configurations. The obtained results demonstrate that the resonance frequency of paper-based mechanical systems can be easily tuned by the imbibition of a glycerol–water solution. This study could lead to the development of tunable paper-based mechanical systems for specific applications such as energy harvesters and hygro-mechanical-based sensors.

Dynamic Response of Eccentric Swinging Sheet Transfer Mechanism with Kinematic Pair Clearances

2013 ◽  
Vol 312 ◽  
pp. 182-185
Author(s):  
Fang Cai ◽  
Jian Qing Zhang ◽  
Xiu Feng Ma
Keyword(s):  
Dynamic Response ◽  
Dynamic Characteristics ◽  
Dynamic Performance ◽  
Transfer Mechanism ◽  
Kinematic Pair ◽  
Nonlinear Dynamic Response ◽  
Nonlinear Characteristics ◽  
Continuous Contact ◽  
The Stability ◽  
Transfer Mechanisms

To research the influence of kinematic pair clearances on the dynamic performance of eccentric swinging sheet transfer mechanism used in Sheet-fed offset J2108, a dynamic model was established based on the clearances characteristics and the continuous contact hypothesis. Consequently, the dynamic characteristics of sheet transfer mechanisms output can be researched quantitatively. The results indicate that sheet transfer mechanisms dynamic response appears strong nonlinear characteristics while considering kinematic pair clearances, which seriously affects the sheet transfer mechanisms stability and precision. Therefore, the study on the nonlinear dynamic response of sheet transfer mechanism can provide foundation to improve the stability.

scholarly journals Characterization of Giant Magnetostrictive Materials Using Three Complex Material Parameters by Particle Swarm Optimization

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1416
Author(s):  
Yukai Chen ◽  
Xin Yang ◽  
Mingzhi Yang ◽  
Yanfei Wei ◽  
Haobin Zheng
Keyword(s):  
Classical Method ◽  
Lumped Parameter Model ◽  
Complex Material ◽  
Material Parameters ◽  
Magnetostrictive Materials ◽  
Lumped Parameter ◽  
Giant Magnetostrictive Materials ◽  
Power Transducer ◽  
And Performance ◽  
The Stability

Complex material parameters that can represent the losses of giant magnetostrictive materials (GMMs) are the key parameters for high-power transducer design and performance analysis. Since the GMMs work under pre-stress conditions and their performance is highly sensitive to pre-stress, the complex parameters of a GMM are preferably characterized in a specific pre-stress condition. In this study, an optimized characterization method for GMMs is proposed using three complex material parameters. Firstly, a lumped parameter model is improved for a longitudinal transducer by incorporating three material losses. Then, the structural damping and contact damping are experimentally measured and applied to confine the parametric variance ranges. Using the improved lumped parameter model, the real parts of the three key material parameters are characterized by fitting the experimental impedance data while the imaginary parts are separately extracted by the phase data. The global sensitivity analysis that accounts for the interaction effects of the multiple parameter variances shows that the proposed method outperforms the classical method as the sensitivities of all the six key parameters to both impedance and phase fitness functions are all high, which implies that the extracted material complex parameters are credible. In addition, the stability and credibility of the proposed parameter characterization is further corroborated by the results of ten random characterizations.

Effects of Bearing Radial Internal Clearance on Dynamic Behavior and Bifurcations in Planetary Gears

2011 ◽  
Author(s):  
Yi Guo ◽  
Robert G. Parker
Keyword(s):  
Dynamic Response ◽  
Harmonic Balance Method ◽  
Nonlinear Behavior ◽  
Nonlinear Effects ◽  
Lumped Parameter Model ◽  
Solution Stability ◽  
Planetary Gears ◽  
Gear Mesh ◽  
Bearing Clearance ◽  
Lumped Parameter

This study investigates the dynamics of planetary gears where nonlinearity is induced by bearing clearance. Lumped-parameter and finite element models of planetary gears with bearing clearance, tooth separation, and gear mesh stiffness variation are developed. The harmonic balance method with arc-length continuation is used to obtain the dynamic response of the lumped-parameter model. Solution stability is analyzed using Floquet theory. Rich nonlinear behavior is exhibited in the dynamic response, consisting of nonlinear jumps and a hardening effect induced by the transition from no bearing contact to contact. The bearings of the central members (sun, ring, and carrier) impact against the bearing races near resonance, which leads to coexisting solutions in wide speed ranges, grazing bifurcation, and chaos. Secondary Hopf bifurcation is the route to chaos. Input torque can significantly suppress the nonlinear effects caused by bearing clearance.

Design, Analysis, Experimentation, and Control of a Partially Compliant Bistable Mechanism

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Ayse Tekes ◽  
Hongkuan Lin ◽  
Kevin McFall
Keyword(s):  
Dynamic Response ◽  
Elliptic Integral ◽  
Three Dimensional ◽  
Design Analysis ◽  
Lumped Parameter Model ◽  
Lumped Parameter ◽  
Rigid Body Model ◽  
3D Printed ◽  
Bistable Mechanism ◽  
And Control

Abstract This study presents the design analysis and development of a novel partially compliant bistable mechanism. Motion behavior dependence on links and relative angles are analyzed, lumped parameter model is derived, mechanism parts including the compliant members are three-dimensional (3D) printed and a state feedback controller is implemented so that the slider follows a well-defined trajectory if designed as an actuator. The proposed mechanism consists of initially straight, large deflecting fixed-pinned compliant links, rigid links, and a sliding mass. Dynamic response of the mechanism is studied using elliptic integral solutions, pseudo rigid body model (PRBM), vector closure loop equations and Elliptic integrals. Nonlinear model is simulated in matlab simulink using fourth‐order Runge‐Kutta algorithms. The research emphasizes on the realization and dynamic response of the mechanism and the trajectory control of the slider so that the slider can be kept constant at specified distances resulting a dwell motion if designed as a linear actuator.

Mode-Coupled Regenerative Machine Tool Vibrations

2003 ◽  
Author(s):  
Tama´s Kalma´r-Nagy ◽  
Francis C. Moon
Keyword(s):  
Machine Tool ◽  
Cutting Tool ◽  
Chip Thickness ◽  
The Other ◽  
Lumped Parameter Model ◽  
Regenerative Effect ◽  
Lumped Parameter ◽  
Tool Vibrations ◽  
The Stability ◽  
Effect Time

In this paper a new 3 degree-of-freedom lumped-parameter model for machine tool vibrations is developed and analyzed. One mode is shown to be stable and decoupled from the other two, and thus the stability of the system can be determined by analyzing the remaining two modes. It is shown that this mode-coupled nonconservative cutting tool model including the regenerative effect (time delay) can produce an instability criteria that admits low-level or zero chip thickness chatter.

EFFECT OF SURFACE LAYER ON ELECTROMECHANICAL STABILITY OF TWEEZERS AND CANTILEVERS FABRICATED FROM CONDUCTIVE CYLINDRICAL NANOWIRES

2016 ◽  
Vol 23 (02) ◽  
pp. 1550101 ◽  
Author(s):  
MARYAM KEIVANI ◽  
ALI KOOCHI ◽  
HAMID M. SEDIGHI ◽  
MOHAMADREZA ABADYAN ◽  
AMIN FARROKHABADI ◽  
...  
Keyword(s):  
Surface Layer ◽  
Homotopy Perturbation Method ◽  
Differential Quadrature Method ◽  
Surface Elasticity ◽  
Lumped Parameter Model ◽  
Governing Equations ◽  
Lumped Parameter ◽  
The Stability ◽  
The Impact ◽  
Effect Of Surface

Herein, the impact of surface layer on the stability of nanoscale tweezers and cantilevers fabricated from nanowires with cylindrical cross section is studied. A modified continuum based on the Gurtin–Murdoch surface elasticity is applied for incorporating the presence of surface layer. Considering the cylindrical geometry of the nanowire, the presence of the Coulomb attraction and dispersion forces are incorporated in the derived formulations. Three different approaches, i.e. numerical differential quadrature method (DQM), an approximated homotopy perturbation method (HPM) and developing lumped parameter model (LPM) have been employed to solve the governing equations. The impact of surface layer on the instability of the system is demonstrated.

A Multi-domain Approach to the Stabilization of Electrodynamic Levitation Systems

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Renato Galluzzi ◽  
Salvatore Circosta ◽  
Nicola Amati ◽  
Andrea Tonoli ◽  
Angelo Bonfitto ◽  
...  
Keyword(s):  
State Of The Art ◽  
Point Of View ◽  
Lumped Parameter Model ◽  
Extensive Literature ◽  
Lumped Parameter ◽  
Levitation System ◽  
The Stability ◽  
Linearized Model ◽  
Proper Interpretation ◽  
System Paradigm

Abstract The Hyperloop transportation system paradigm has gained increasing attention in the last years due to its potential advantages in technology, territory, and infrastructure. From an engineering point of view, it would lead to fast, safe, efficient transportation of passengers and cargo. The stability of the electrodynamic levitation system represents a key enabling aspect of Hyperloop. In this context, the state of the art presents numerous attempts to stabilize these systems without definitive guidelines on how to attain proper, stable behavior. Furthermore, research has provided extensive literature in the context of electrodynamic bearings, which requires proper interpretation and generalization into the translational domain. In this paper, we address the stabilization of levitation systems by reproducing the strong interaction between the electrodynamic phenomenon and the mechanical domain. A novel lumped-parameter model with a multiple-branch circuit is proposed and tuned through finite-element simulations to replicate the electrodynamic behavior. The multi-domain equations are linearized and the unstable nature of the levitation system is identified and discussed. Then, a suitable method to add damping and optimize stability is studied. Finally, the linearized model is compared with the nonlinear representation to validate the followed approach.

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