Modeling of Mass-Spring-Damper System by Complex Stiffness Method

2014 ◽  
Vol 983 ◽  
pp. 420-423
Author(s):  
Sheng Guo Zhang ◽  
Xiao Ping Dang
Keyword(s):  
Transfer Functions ◽  
Mechanical Systems ◽  
Stiffness Method ◽  
In Series ◽  
Equivalent Complex ◽  
Mass Spring

This paper aims at directly modeling the transfer functions of mass-spring-damper systems. Using complex stiffness of mass, spring, and damper elements and equivalent complex stiffness of these elements in series and/or in parallel, the transfer functions of the mass-spring-damper systems are modeled quickly. This is very convenient to the modeling of the complicated mechanical systems.

Proof and Application of Complex Impedance of Inductor and Capacitor

2014 ◽  
Vol 568-570 ◽  
pp. 1213-1216
Author(s):  
Sheng Guo Zhang ◽  
Xiao Ping Dang
Keyword(s):  
Transfer Function ◽  
Laplace Transformation ◽  
Transfer Functions ◽  
Complex Impedance ◽  
Transformation Method ◽  
Active Circuit ◽  
In Series ◽  
Equivalent Complex ◽  
Circuit Networks ◽  
Laplace Transformation Method

This paper aims at proving the complex impedance of the inductor and capacitor elements and applying the proved complex impedance concept to directly obtain the transfer function model of the complicated circuit network. Based on Laplace Transformation method, the complex impedances of the inductor and capacitor elements are proved. Using the proved complex impedances and the equivalent complex impedances in series and in parallel, both the transfer functions of the passive and active circuit networks are modeled. This facilitates the transfer function modeling of the complicated circuit network very much.

A Simple and Quick Technique for the Determination of Transfer Functions of Linear Mechanical Systems

1994 ◽  
Vol 22 (4) ◽  
pp. 259-277
Author(s):  
B. Mashadi
Keyword(s):  
Simple Model ◽  
Time Domain ◽  
Digital Computer ◽  
Transfer Functions ◽  
Mechanical Systems ◽  
Computer Programs ◽  
Laplace Domain ◽  
Linear Elements ◽  
Mass Spring

Usual methods for the determination of the transfer functions of mechanical systems consisting of linear elements (i.e. mass, spring and damper), are practical only for simple cases. In a complicated system with many elements, the process is tedious and error-prone. In this work, with the aid of a simple model which easily transfers the system from time domain into the Laplace domain, the general forms of the transfer functions of the system have been derived. In this report, three general forms of such systems are discussed and examples are considered. The advantages of this method in addition to its simplicity are that the transfer functions provide numerators and denominators (characteristic equations) separately; the formulae are easily applicable in digital computer programs; and finally, the method can be used for academic purposes (for example, for quick problem-checking by the instructor).

scholarly journals Trajectory Planning for Mechanical Systems Based on Time-Reversal Symmetry

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 792
Author(s):  
Stepan Ozana ◽  
Tomas Docekal ◽  
Aleksandra Kawala-Sterniuk ◽  
Jakub Mozaryn ◽  
Milos Schlegel ◽  
...  
Keyword(s):  
Trajectory Planning ◽  
Time Reversal ◽  
Mechanical Systems ◽  
Open Loop ◽  
Control Signal ◽  
Time Reversal Symmetry ◽  
Time Symmetry ◽  
Unique Method ◽  
Flow Of Time ◽  
Mass Spring

The generation of feasible trajectories poses an eminent task in the field of control design in mechanical systems. The paper demonstrates innovative approach in trajectory planning for mechanical systems via time-reversal symmetry. It also presents two case studies: mass-spring-damper and inverted pendulum on the cart. As real systems break the time-reversal symmetry, the authors of this work propose a unique method in order to overcome this drawback. It computes a feed-forward reference control signal and state trajectories. The proposed solution enables compensation for the effects of couplings, which break the time-symmetry by a special proposed measure. The method suppresses the overall open-loop accumulated error and produces high-quality favorable control and state trajectories. Furthermore, the existence of the designed control signal and state trajectories is guaranteed if the equations of the motion have a solution in the direct flow of time.

Tire Longitudinal Mechanics Properties under Various Braking Conditions

2014 ◽  
Vol 654 ◽  
pp. 82-86
Author(s):  
Hai Dong Wu ◽  
Kong Hui Guo
Keyword(s):  
Dynamic Properties ◽  
Tire Model ◽  
In Series ◽  
Mass Spring

A dynamical tire model under uneven road is reviewed and the model is adapted to carry out simulation of various braking conditions. The damped characters of the tire at low rotated speed are improved through the study on the system of mass-spring-damper in series. A simple and effective brake model is designed and several extreme braking conditions are simulated. The results of simulation show obvious dynamic properties of the tire at various braking excitation.

scholarly journals Analysis and optimization of the effects of frictional and viscous dampers on dynamical systems

2019 ◽  
Vol 38 (2) ◽  
pp. 255-269
Author(s):  
Marlon Wesley Machado Cunico ◽  
Jennifer Desiree Medeiros Cavalheiro
Keyword(s):  
Frequency Domain ◽  
Degrees Of Freedom ◽  
Transfer Functions ◽  
Mechanical Systems ◽  
Static Friction ◽  
Coulomb Force ◽  
Dynamic Responses ◽  
Dynamical Response ◽  
Viscous Dampers ◽  
Three Degrees Of Freedom

Over the last several years, the complexity of products has been increasing in parallel to the product cost thus becoming one of main focal points for development. On the other hand, although several applications struggle to fix vibration problems, highlighting the importance of damper design, literature that compares the benefits and disadvantages between of dry-frictional, viscous, and Coulomb–viscous dampers is still rare. Owing to this, the main goal of this work is to present a study that compares the dynamical response of mechanical systems against several damper types. For this research, we analyzed the effects of three types of damper (viscous, Coulomb–viscous, and dry-frictional dampers) on two mechanical systems. The first system consists of a mass-spring-damper with one degree of freedom, while the second system is a rotational machine with three degrees of freedom. The sensibility analyses of each damper were also studied, where the viscosity, Coulomb force, static friction, and Stribeck decay were the variables. In this work, mechanical systems were studied in a forced vibration condition and analyzed in the time and frequency domain in addition to identifying the main transfer functions in the frequency domain. In this analysis, the displacement, receptance, and force reaction were considered to be the study responses. After analyzing the main effect of damper coefficients on the general dynamic responses, we performed an optimization study in order to evidence the optimal configurations of either majorly viscous or frictional damper. Lastly, we analyzed the main behavior of this optimized damper on three-degrees-of-freedom rotational dynamic system.

DYNAMICS OF ELECTROSTATICALLY ACTUATED MICRO-ELECTRO-MECHANICAL SYSTEMS: SINGLE DEVICE AND ARRAYS OF DEVICES

2009 ◽  
Vol 19 (03) ◽  
pp. 1007-1022 ◽  
Author(s):  
V. Y. TAFFOTI YOLONG ◽  
P. WOAFO
Keyword(s):  
Chaotic Behavior ◽  
Equilibrium Points ◽  
Dynamical Behavior ◽  
Mechanical Systems ◽  
Largest Lyapunov Exponent ◽  
Mems Devices ◽  
Micro Electro Mechanical Systems ◽  
Electrostatically Actuated ◽  
In Series ◽  
Electrostatic Coupling

The dynamical behavior of micro-electro-mechanical systems (MEMS) with electrostatic coupling is studied. A nonlinear modal analysis approach is applied to decompose the partial differential equation into a set of ordinary differential equations. The stability analysis of the equilibrium points is investigated. The amplitudes of the harmonic oscillatory states in the triple resonant states are obtained and discussed. Chaotic behavior is investigated using bifurcations diagram and the largest Lyapunov exponent. The dynamics of the MEMS with multiple functions in series is also investigated as well as the transitions boundaries for the complete synchronization state in a shift-invariant set of coupled MEMS devices.

Towards fractional sensors

2018 ◽  
Vol 25 (1) ◽  
pp. 52-60 ◽  
Author(s):  
António M. Lopes ◽  
J. A. Tenreiro Machado ◽  
Alexandra M. Galhano
Keyword(s):  
Fractional Calculus ◽  
Fractional Order ◽  
Mechanical Systems ◽  
Modular Construction ◽  
Proper Selection ◽  
Micro Electro Mechanical Systems ◽  
Mechanical Structure ◽  
Mass Spring ◽  
Selection Of

This paper proposes a new sensor architecture inspired on the classical accelerometer and the fractional calculus. The fractional sensor (FS) adopts a modular construction with [Formula: see text] stages, where each stage consists of an association of mass–spring–damper elements. A proper selection of the elements in the global mechanical structure yields fractional-order characteristics. The frequency and time responses of the proposed apparatus are studied and compared with those exhibited by an ideal fractional order device. The FS can be implemented by means of modern fabrication techniques used with micro electro-mechanical systems.

Coordinated Operation of Centrifugal Compressors in Series via Model Predictive Control

2016 ◽  
Author(s):  
Mehmet Mercangöz ◽  
Andrea Stefani ◽  
Andrea Cortinovis
Keyword(s):  
High Performance ◽  
Transfer Functions ◽  
Control Strategies ◽  
Step Response ◽  
Response Analysis ◽  
Centrifugal Compressors ◽  
Control Loops ◽  
Plant Behavior ◽  
In Series ◽  
Surge Control

This paper investigates the control challenges in the operation of centrifugal compressors in series configuration, which arise from the interactions of the different control loops for process and anti-surge control. The investigation is carried out with simulations, where two compressors in series are considered to represent the simplest possible case for systems analysis. The simulations are based on a well-known nonlinear compressor model to represent the plant behavior as close to reality as possible. The paper starts with the derivation of linear transfer functions from step response analysis, which are used to develop both advanced decentralized control solutions using loop decoupling schemes as well as a model predictive controller (MPC). The various alternative control strategies are then investigated by introducing a typical downstream disturbance case that pushes the compressors towards surge conditions while creating interactions among all control loops. The simulation results are analyzed to determine the advantages and the shortcomings of the different control strategies. The MPC based approach stands out as a high performance alternative to traditional control schemes relying on simple feedback and feedforward elements.

Sign in / Sign up

Export Citation Format

Share Document