Vibration Analysis and Optimization of Wobble Plate Engine

2012 ◽  
Vol 479-481 ◽  
pp. 2267-2270
Author(s):  
Jing Jin ◽  
Zhen Shan Zhang ◽  
Xin Xiong
Keyword(s):  
Dynamic Model ◽  
Time Domain ◽  
Vibration Analysis ◽  
System Response ◽  
Frequency Range ◽  
Flexible System ◽  
Engine Vibration ◽  
Adams Software ◽  
The Time Domain ◽  
Rubber Isolator

The rigid-flexible system dynamic model of wobble plate engine was created by BUSH element and so on in ADAMS software. And stiffness optimized calculation of engine rubber isolator ring and spring was done by ADAMS optimized module. By comparing the time domain and frequency domain vibration response before optimization and after optimization, the feasibility of optimized method for decreasing engine vibration and changing system response frequency range was verified. This method could provide important reference for vibration dynamic model creating of engine or analogous mechanical system. Its conclusions also could provide reference for decreasing vibration study.

Controllability Ellipsoid to Evaluate the Performance of Mobile Manipulators for Manufacturing Tasks

2017 ◽  
Vol 9 (6) ◽  
Author(s):  
Stephen L. Canfield ◽  
Reabetswe M. Nkhumise
Keyword(s):  
Time Domain ◽  
Controller Design ◽  
Control Design ◽  
Quantitative Measure ◽  
Space Representation ◽  
System Response ◽  
Geometric Representation ◽  
Mobile Manipulators ◽  
Control Parameters ◽  
The Time Domain

This paper develops an approach to evaluate a state-space controller design for mobile manipulators using a geometric representation of the system response in tool space. The method evaluates the robot system dynamics with a control scheme and the resulting response is called the controllability ellipsoid (CE), a tool space representation of the system’s motion response given a unit input. The CE can be compared with a corresponding geometric representation of the required motion task (called the motion polyhedron) and evaluated using a quantitative measure of the degree to which the task is satisfied. The traditional control design approach views the system response in the time domain. Alternatively, the proposed CE views the system response in the domain of the input variables. In order to complete the task, the CE must fully contain the motion polyhedron. The optimal robot arrangement would minimize the total area of the CE while fully containing the motion polyhedron. This is comparable to minimizing the power requirements of robot design when applying a uniform scale to all inputs. It will be shown that changing the control parameters changes the eccentricity and orientation of the CE, implying a preferred set of control parameters to minimize the design motor power. When viewed in the time domain, the control parameters can be selected to achieve desired stability and time response. When coupled with existing control design methods, the CE approach can yield robot designs that are stable, responsive, and minimize the input power requirements.

scholarly journals Ultra Wideband Coplanar Waveguide Antenna with an Improved Gain using a Frequency Selective Surfaces (FSS)

2019 ◽  
Vol 8 (9S) ◽  
pp. 145-149
Keyword(s):  
Time Domain ◽  
Coplanar Waveguide ◽  
Unit Cell ◽  
Ultra Wideband ◽  
Frequency Range ◽  
Rectangular Slot ◽  
Improved Performance ◽  
Set Up ◽  
The Time Domain ◽  
Uwb Applications

In this article, an ultra-wideband FSS reflector has been proposed to enhance the gain of a CPW antenna for UWB applications. A CPW fed antenna having dimensions of 38mm×38mm×1.605mm and FSS unit cell having dimensions 14mm × 14mm × 1.605 mm are presented in the paper. A rectangular slot and stubs are interleaved at the outer edges of the patch for achieving desired characteristics of an ultra-wideband for the frequency range of 3.39 GHz to 12.9 GHz. Simulation results carried out using the CST microwave 2016 version in the time domain are presented for the proposed antenna. An FSS unit cell designed and simulated using periodic boundary conditions and floquet ports is presented. The combined setup of an array of FSS reflector behind the antenna has been simulated in the time domain. This set up shows an improved performance in terms of antenna’s gain. A maximum and minimum gain of 8.14 dB and 4.98 dB has been observed with the presence of FSS reflector behind the coplanar waveguide antenna. A significant improvement of 2.9 dB has been observed over the entire band of antenna’s operation

A generalization of the Laplace transform

1967 ◽  
Vol 63 (1) ◽  
pp. 155-160 ◽  
Author(s):  
H. S. Dunn
Keyword(s):  
Laplace Transform ◽  
Time Domain ◽  
Finite Interval ◽  
Integral Transformation ◽  
System Response ◽  
Simple Scheme ◽  
Exponential Order ◽  
The Laplace Transform ◽  
The Time Domain ◽  
Determine System

AbstractAn integral transformation is denned over a finite interval of the time domain. When the Laplace transform exists, the finite transform yields identical results. However, the finite transform is found to be considerably more general than the Laplace transform. It permits consideration of functions which are not of exponential order, leads to a simple scheme to determine system response, and is applicable to boundary-value problems.

The Dynamics Analysis of Rolling Movable Teeth Reducer

2011 ◽  
Vol 221 ◽  
pp. 429-435
Author(s):  
Jun Fei Wu ◽  
Xiao Chen Zhu ◽  
Wei Gao ◽  
Ying Yu
Keyword(s):  
Time Domain ◽  
Optimization Design ◽  
Virtual Prototype ◽  
Dynamics Analysis ◽  
Engineering Analysis ◽  
Input Shaft ◽  
Kinematics Simulation ◽  
Adams Software ◽  
Simulation Results ◽  
The Time Domain

The structure and operating principle of rolling movable teeth reducer are introduced in this paper. Through the virtual prototype technology, the modeling of rolling movable teeth reducer is made by Pro/E software,and is had the kinematics simulation and dynamic analysis by ADAMS software. The simulation results show that the speed curves of the input shaft and the output shaft of rolling movable teeth reducer coincide with the theory transmission. It proves correctness of virtual prototype. The mechanical properties of rolling movable teeth reducer is obtained by the time-domain graph of meshing force. It provides the basis for the optimization design and engineering analysis of reducer.

scholarly journals Spatiotemporal Distribution Characterization for Terahertz Waves Generated From Plasma Induced by Two-Color Pulses

2021 ◽  
Vol 9 ◽  
Author(s):  
Erli Wang ◽  
Yulong Wang ◽  
Wenfeng Sun ◽  
Xinke Wang ◽  
Shengfei Feng ◽  
...  
Keyword(s):  
Time Domain ◽  
Focal Plane ◽  
Spatiotemporal Distribution ◽  
Matching Theory ◽  
Thz Radiation ◽  
Phase Matching ◽  
Frequency Range ◽  
Terahertz Waves ◽  
Lower Frequency Range ◽  
The Time Domain

The spatiotemporal distribution of terahertz (THz) radiation from plasma has been demonstrated with the technology of THz focal-plane imaging. It has been found that the spatiotemporal distribution will vary with the frequency, as well as the length of plasma. A doughnut-shaped distribution appears in the lower frequency range, while the bell-shaped distribution corresponds to the higher frequency range. For plasmas with different lengths, their generated THz images in the time domain are similar, the THz images in the frequency domain as well. The spatiotemporal distributions are simulated with the off-axis-phase matching theory. All the findings will renew the understanding of the THz generation from plasma induced by two-color pulses.

scholarly journals Random analysis of coupled vehicle-bridge systems with local nonlinearity based on explicit time-domain method

2021 ◽  
Author(s):  
Huan Huang ◽  
Hengbin Zheng ◽  
Jianliang Deng ◽  
Wenxiong Li ◽  
Yuyu Li
Keyword(s):  
Time Domain ◽  
Vibration Analysis ◽  
Time Instant ◽  
Time Domain Method ◽  
Equivalent Linearization ◽  
Linearization Technique ◽  
Suspension Spring ◽  
Domain Method ◽  
The Time Domain ◽  
Bridge System

Abstract Based on the explicit time-domain method in conjunction with the equivalent linearization technique, an efficient analysis algorithm is developed for the random vibration analysis of the coupled vehicle-bridge system with local nonlinear components under the random irregular excitation from a bridge deck. With the coupled vehicle-bridge system divided into two subsystems, the equivalent linearized subsystem for the vehicle subsystem with the hysteretic suspension spring is constructed for the given time instant using the equivalent linearization technique. Then the dimension-reduction vibration analysis for the equivalent linearized coupled vehicle-bridge system can be carried out based on the time-domain explicit method, which has been proven to be highly efficient. The numerical example indicates that the proposed approach is of feasibility.

A New Method for Optimizing Friction Damping in Randomly Excited Systems

1989 ◽  
Author(s):  
T. M. Cameron ◽  
J. H. Griffin
Keyword(s):  
Time Domain ◽  
Turbine Blades ◽  
Single Mode ◽  
Random Excitation ◽  
Degree Of Freedom ◽  
System Response ◽  
Friction Damping ◽  
Single Mode Approximation ◽  
The One ◽  
The Time Domain

A method is developed that can be used to calculate the stationary response of randomly excited nonlinear systems. The method iterates to obtain the fast Fourier transform of the system response, returning to the time domain at each iteration to take advantage of the ease in evaluating nonlinearities there. The updated estimates of the nonlinear terms are transformed back into the frequency domain in order to continue iterating on the frequency spectrum of the staionary response. This approach is used to calculate the response of a one degree of freedom system with friction damping that is subjected to random excitation. The one degree of freedom system provides a single mode approximation of systems (e.g. turbine blades) with friction damping. This study investigates various strategies that can be used to optimize the friction load so as to minimize the response of the system.

scholarly journals Transient System Model for the Analysis of Structural Dynamic Interactions of Electric Drivetrains

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1108
Author(s):  
Marius Franck ◽  
Jan Philipp Rickwärtz ◽  
Daniel Butterweck ◽  
Martin Nell ◽  
Kay Hameyer
Keyword(s):  
Time Domain ◽  
Vibration Analysis ◽  
System Approach ◽  
System Model ◽  
Dynamic Interactions ◽  
Structural Dynamic ◽  
Transient Behaviour ◽  
Transient System ◽  
The Time Domain ◽  
Modelling Approach

In electric drivetrains, the traction machines are often coupled to a gear transmission. For the noise and vibration analysis of such systems, linearised system models in the frequency domain are commonly used. In this paper, a system approach in the time domain is introduced, which gives the advantage of analysing the transient behaviour of an electric drivetrain. The focus in this paper is on the dynamic gear model. Finally, the modelling approach is applied to an exemplary drivetrain, and the results are discussed.

Beating the Nyquist Limit by Means of Interleaved Alternated Delay Sampling: Extension of Lower Mass Limit in Direct-Mode Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

1988 ◽  
Vol 42 (2) ◽  
pp. 199-203 ◽  
Author(s):  
Francis R. Verdun ◽  
Tom L. Ricca ◽  
Alan G. Marshall
Keyword(s):  
Fourier Transform ◽  
Time Domain ◽  
Sampling Rate ◽  
Sampling Period ◽  
Sampling Frequency ◽  
Ion Cyclotron Resonance ◽  
Frequency Range ◽  
Lower Mass ◽  
The Time Domain ◽  
Lower Mass Limit

According to the Nyquist theorem, the highest signal frequency which can be represented without foldover (aliasing) in a Fourier transform frequency-domain discrete spectrum is one-half of the time-domain sampling frequency. For example, since ion cyclotron resonance (ICR) frequency is inversely related to ionic mass-to-charge ratio, m/z, the highest ICR frequency (corresponding to the lowest correctly represented m/z) in direct-mode Fourier transform ICR mass spectrometry is restricted to one-half of the maximum sampling frequency, or about m/z ≥ 18 at 3.058 tesla (T) for a maximum sampling frequency of about 5.2 MHz. In this paper, we show that interleaved addition of two digitized time-domain transient signals, one of which is delayed by one-half of one sampling period (i.e., half of one cycle of the time-domain sampling frequency) with respect to the other, generates a time-domain discrete waveform which is indistinguishable from a single waveform produced by sampling at twice the original sampling rate. Thus, provided that the two transients have (or have been normalized to) the same magnitude, one can double the Nyquist-limited frequency range. If the sampling period is divided into three or more equal parts, with interleaved addition of three or more correspondingly delayed transients, the same method can further increase the upper frequency limit. The method is applied to the experimental doubling or quadrupling of FT/ICR direct-mode frequency range, as for example in the extension of the lower mass limit to below m/z = 12 at 3.058 T with a sampling rate of only 4.0 MHz.

scholarly journals An Alternating Frequency/Time Domain Method for Calculating the Steady-State Response of Nonlinear Dynamic Systems

1989 ◽  
Vol 56 (1) ◽  
pp. 149-154 ◽  
Author(s):  
T. M. Cameron ◽  
J. H. Griffin
Keyword(s):  
Steady State ◽  
Frequency Domain ◽  
Dynamic Systems ◽  
Time Domain ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Systems ◽  
System Response ◽  
Steady State Response ◽  
State Response ◽  
The Time Domain

A method is proposed for analyzing the steady-state response of nonlinear dynamic systems. The method iterates to obtain the discrete Fourier transform of the system response, returning to the time domain at each iteration to take advantage of the ease in evaluating nonlinearities there—rather than analytically describing the nonlinear terms in the frequency domain. The updated estimates of the nonlinear terms are transformed back into the frequency domain in order to continue iterating on the frequency spectrum of the steady-state response. The method is demonstrated by solving a problem with friction damping in which the excitation has multiple discrete frequencies.

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