scholarly journals Vibration Control of Building Subjected to Harmonic Excitation

10.29007/ng9v ◽  
2018 ◽  
Author(s):  
Narayan B. Makwana ◽  
Snehal V. Mevada ◽  
Vishal B. Patel
Keyword(s):  
Resonance Condition ◽  
Harmonic Excitation ◽  
Viscous Damper ◽  
State Space Method ◽  
Resonance Case ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
The Mathematical Model ◽  
Story Building ◽  
Space Method

This paper includes the study of behavior of a single degree of freedom system with viscous dampers subjected to harmonic excitation. In this study one story building is considered. The mathematical model of building subjected to harmonic excitation is obtained and its solution is obtained by state space method. The viscous damper is considered for the building with different percentage of damping. The response of building under resonance and non-resonance condition is obtained and it is observed that it can be significantly reduced by installing viscous damper. It is further observed that the linear viscous damper is more effective in reducing the responses for resonance case.

Passive, Transitioning Mounts for Simultaneous Shock and Vibration Isolation

2012 ◽  
Author(s):  
Emad Shahid ◽  
Al Ferri
Keyword(s):  
Vibration Isolation ◽  
Sliding Friction ◽  
Design Strategy ◽  
Harmonic Excitation ◽  
Viscous Damper ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
In Series ◽  
Velocity Input ◽  
Tradeoff Curve

A design strategy to simultaneously mitigate the effects of both shock and vibration is introduced. The proposed isolation mount is a passive, transitioning mount and consists of sliding friction elements in series connection with springs and dampers. A linear and a displacement dependent viscous damper are considered, while linear, hardening and softening springs, are considered. The isolation mount’s response is determined by numerical simulation. For a single-degree-of-freedom system, the tradeoff curve for a half-sine velocity input is determined, as is the nonlinear transmissibility for harmonic excitation. The method is found to achieve satisfactory isolation against shock events as well as persistent harmonic inputs. The suggested mount configuration was also found to have good performance against a ‘combined’ input with both resonant and transient content.

The Dynamic Response of a System With Preloaded Compliance

1988 ◽  
Vol 110 (3) ◽  
pp. 278-283 ◽  
Author(s):  
S. W. Shaw ◽  
P. C. Tung
Keyword(s):  
Dynamic Response ◽  
Piecewise Linear ◽  
Harmonic Excitation ◽  
Periodic Motions ◽  
Chaotic Motions ◽  
Linear Features ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Stable Periodic ◽  
Model Equations

We consider the dynamic response of a single degree of freedom system with preloaded, or “setup,” springs. This is a simple model for systems where preload is used to suppress vibrations. The springs are taken to be linear and harmonic excitation is applied; damping is assumed to be of linear viscous type. Using the piecewise linear features of the model equations we determine the amplitude and stability of the periodic responses and carry out a bifurcation analysis for these motions. Some parameter regions which contain no simple stable periodic motions are shown to possess chaotic motions.

scholarly journals Simulation Analysis of One Degree of Freedom Motion of Electromagnetic Spherical Joint based on Maxwell

2021 ◽  
Vol 2085 (1) ◽  
pp. 012014
Author(s):  
Haoran Wang ◽  
Fucong Liu ◽  
Sai Lou
Keyword(s):  
Mathematical Model ◽  
Simulation Analysis ◽  
Lagrange Equation ◽  
Degree Of Freedom ◽  
Spherical Joint ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Structure And Motion ◽  
The Mathematical Model ◽  
The Relationship

Abstract In order to improve the stiffness of the spherical joint of the robot, reduce the difficulty of manufacturing and the complexity of the control system, this paper proposed a method of spherical joint and digital drive of the robot based on the electromagnetic principle. Firstly, introduces the structure and motion principle of the spherical joint of the robot, establishes the mathematical model of the spherical joint and establishes the dynamic model according to the second Lagrange equation. after that, the relationship between the number of ampire-turns of the electromagnet on the spherical joint, the attitude Angle of the rotor and the force of the rotor was obtained by simulating the single degree of freedom of the joint based on Ansys maxwell and Matlab, which provided a basis for the realization of the digital drive of the spherical joint.

scholarly journals Shock Performance of Different Semiactive Damping Strategies

2010 ◽  
Vol 8 (02) ◽  
Author(s):  
D. F. Ledezma-Ramirez ◽  
N. Ferguson ◽  
M. Brennan
Keyword(s):  
Harmonic Excitation ◽  
Degree Of Freedom ◽  
Harmonic Vibration ◽  
Passive Stiffness ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Variable Damping ◽  
Stiffness And Damping ◽  
Shock Pulses

The problem of shock generated vibration is presented and analyzed. The fundamental background is explained based on the analysis of a single degree-of-freedom model with passive stiffness and damping. The advantages and limitations of such a shock mount are discussed. Afterwards, different semi-active strategies involving variable damping are presented. These strategies have been used for harmonic excitation but it is not clear how they will perform during a shock. This paper analyzes the different variable damping schemes already used for harmonic vibration in order to find any potential advantages or issues for theoretical shock pulses.

Periodic Motions in a Single-Degree-of-Freedom System Under Both an Aerodynamic Force and a Harmonic Excitation

2019 ◽  
Author(s):  
Bo Yu ◽  
Albert C. J. Luo
Keyword(s):  
Numerical Simulations ◽  
Analytical Approach ◽  
Aerodynamic Force ◽  
Excitation Frequency ◽  
Harmonic Excitation ◽  
Degree Of Freedom ◽  
Periodic Motions ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Stable Period

Abstract In this paper, a semi-analytical approach was used to predict periodic motions in a single-degree-of-freedom system under both aerodynamic force and harmonic excitation. Using the implicit mappings, the predictions of period-1 motions varying with excitation frequency are obtained. Stability of the period-1 motions are discussed, and the corresponding eigenvalues of period-1 motions are presented. Finally, numerical simulations of stable period-1 motions are illustrated.

Dynamics of a Free Play Type of Nonlinearity System Under Deterministic and Random Excitations

1995 ◽  
Author(s):  
Ismail I. Orabi
Keyword(s):  
Gaussian White Noise ◽  
Harmonic Excitation ◽  
Free Play ◽  
Nonlinear Structures ◽  
Single Degree Of Freedom ◽  
Linearization Technique ◽  
Single Degree ◽  
Nonlinear Responses ◽  
Digital Simulations ◽  
Good Agreement

Abstract The dynamics of nonlinear structures under harmonic and random excitations is studied. The harmonic excitation is modeled by periodic loadings while the random excitations is modeled by segments of stationary Gaussian white noise processes. Transient responses of a single-degree-of-freedom model is studied to illustrate the characteristic of nonlinear responses. A free play type of nonlinearity is considered. The effects of nonlinearities on the overall dynamics of structure is investigated. The linearization technique is used to calculate the response statistics. To check the accuracy of the linearization technique, the results are compared with Monte-Carlo digital simulations and good agreement are observed.

scholarly journals Sliding-vibrating responses of elastic structures

1988 ◽  
Vol 21 (3) ◽  
pp. 190-197
Author(s):  
Yu-An Fu
Keyword(s):  
Rigid Body ◽  
Harmonic Excitation ◽  
Body Motion ◽  
Shake Table ◽  
Reciprocating Motion ◽  
Friction Forces ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Analytical Expressions ◽  
Vibrating Response

By using simulated friction forces, analytical expressions were derived from the sliding-vibrating response of a single degree of freedom system under harmonic excitation or the "disadvantageous period reciprocating motion", taking the mass of the sliding base into consideration. Some of the general laws were studied and some new characteristics determined which had previously been ignored by assuming rigid body motion. The analysis methods adopted in this paper have been confirmed in comparison with the results of model tests on a shake table.

An Experimental Analysis of the Dynamics of Lightly Damped Subcritically Excited Gear Pairs

2007 ◽  
Author(s):  
James R. Ottewill ◽  
R. Eddie Wilson ◽  
Simon A. Neild
Keyword(s):  
Angular Displacement ◽  
Relative Displacement ◽  
Spur Gears ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Input Amplitude ◽  
Numerical Integrator ◽  
Maximum Relative Displacement ◽  
The Mathematical Model ◽  
Experimental Rig

This paper investigates, through experimentation, the inherently nonlinear dynamics that meshing gear pairs display. The experimental rig consists of 1:1 ratio high-module spur gears connected to high precision encoders. The amplitude of a displacement fluctuation input is varied and the relative motion of the two gears is recorded. The experimental trajectories show at least two stable impacting regimes for each fluctuating input amplitude, differing in the magnitude of the relative angular displacement. The amplitude of motions is sometimes comparable to the backlash size, and for some parameters both noisy solutions with large relative displacement amplitudes and quieter, smaller amplitude solutions may occur. A simple single degree of freedom model is derived, based upon a combined constant velocity and fluctuating displacement input. This model is compared with experimental results in order to understand fundamental contact mechanics. Solutions to the mathematical model are generated using a numerical integrator and predict the maximum relative displacement amplitude motions accurately, but not the smaller amplitude motions. This is because the model omits and simplifies certain mechanisms such as meshing impacts and gear eccentricity, both of which will be added in future investigation.

Sign in / Sign up

Export Citation Format

Share Document