Design and multi-objective optimization of magnetorheological damper considering vehicle riding comfort and operation stability

2021 ◽  
pp. 1045389X2110482
Author(s):  
Zhaoxue Deng ◽  
Xinxin Wei ◽  
Xingquan Li ◽  
Shuen Zhao ◽  
Sunke Zhu
Keyword(s):  
Time Domain ◽  
Vehicle Dynamics ◽  
Mr Damper ◽  
Structure Parameters ◽  
Multi Objective Optimization ◽  
Dynamics Model ◽  
Damping Force ◽  
Domain Optimization ◽  
Operation Stability ◽  
The Time Domain

Mostly, magnetorheological (MR) dampers were optimized based on individual performance, without considering the influence of structure parameters change on vehicle performance. Therefore, a multi-objective optimization scheme of MR damper based on vehicle dynamics model was proposed. The finite element method was used to analyze magnetic flux density distribution in tapered damping channel under different structure parameters. Furthermore, the damping force expression of the tapered flow mode MR damper was derived, and the damping force was introduced into the vehicle dynamics model. In order to improve the ride comfort and operation stability of the vehicle, a collaborative optimization platform combining magnetic circuit finite element analysis and vehicle dynamics model was established. Based on this platform, the optimal design variables were determined by comfort and stability sensitivity analysis. The time domain optimization objective and frequency domain optimization objective are proposed simultaneously to overcome the lack of time domain optimization objective. The results show that compared with the time domain optimization and the initial design, the suspension dynamic deflection, tire dynamic load and vehicle body vertical acceleration are decreased after the time-frequency optimization. At the same time, in the frequency domain, the amplitude of vibration acceleration in each working condition is significantly reduced.

Practical Implementation of the Polynomial Representation of Potential Damping in Time Domain Simulations

2005 ◽  
Author(s):  
Hermione J. van Zutphen ◽  
Joost den Haan
Keyword(s):  
Time Domain ◽  
Degrees Of Freedom ◽  
Added Mass ◽  
Least Square ◽  
Space Representation ◽  
Practical Implementation ◽  
Damping Force ◽  
State Space Representation ◽  
Limit Value ◽  
The Time Domain

Time domain simulations are required when analyzing nonlinear vessel behaviour. The usual approach conducting time domain simulations is to transform a complex valued function of frequency dependent damping and added mass to a convolution integral in the time domain. Evaluating the integrals during time domain simulations is computational expensive and the accuracy of the calculation of the limit value of added mass in diffraction calculations is dependent on the panel size of the model. In this paper, an alternative approach based on a polynomial model for damping proposed by K.E. Kaasen et al is extended from a single degree of freedom to a 6 degrees of freedom model of a heavy lift barge. Polynomials for contributions of velocity to the damping force are constructed generically using a least square curve fitting method. The polynomials then are transformed to the time domain counterpart using a state space representation. The quality of the fits of the damping function has a large influence on the resulting damping force in time domain. Furthermore, the higher the order of the differential equation, the larger the number of variables to integrate during a time domain simulation. Consequently, the presented method is not necessarily more efficient in simulations than the traditional retardation functions.

The virtual tuning of an automatic shock absorber

2009 ◽  
Vol 223 (11) ◽  
pp. 2655-2662 ◽  
Author(s):  
W Ren ◽  
J Zhang ◽  
G Jin
Keyword(s):  
Vehicle Dynamics ◽  
Software Package ◽  
Shock Absorber ◽  
Simulation Method ◽  
Dynamics Model ◽  
Design Requirement ◽  
Damping Force ◽  
Detailed Model ◽  
Tuning Method ◽  
Full Vehicle

In automotive shock absorber development, tuning is a very important way to obtain the appropriate performance. Based on numerical simulation method and the MSC.ADAMS software package, a virtual tuning method has been developed for tuning the shock absorber inner valve set parameters to meet the damping force requirement. The first step is to build a detailed model of an automotive shock absorber using MSC.ADAMS/Hydraulics, while the model has been validated using test data and the accuracy is above 90 per cent. Then the validated model can be used for virtual tuning, in which the parameters can be changed and optimized so as to meet the design requirement and to obtain better performance. The shock absorber model can also be integrated into a full vehicle dynamics model, for some full vehicle level tuning. Based on the virtual tuning result, a physical tuning process is performed, which can be more effective and efficient.

Apodisation in the time domain

1992 ◽  
Vol 2 (4) ◽  
pp. 615-620
Author(s):  
G. W. Series
Keyword(s):  
Time Domain ◽  
The Time Domain

JOINT INTERPRETATION OF AIRBORNE ELECTROMAGNETIC DATA IN THE TIME DOMAIN AND FREQUENCY DOMAIN

2018 ◽  
Vol 12 (7-8) ◽  
pp. 76-83
Author(s):  
E. V. KARSHAKOV ◽  
J. MOILANEN
Keyword(s):  
Fourier Transform ◽  
Frequency Domain ◽  
Time Domain ◽  
Frequency Interval ◽  
Single Spectrum ◽  
Simultaneous Inversion ◽  
Homogeneous Half Space ◽  
Time Domain Data ◽  
The Time Domain

Тhe advantage of combine processing of frequency domain and time domain data provided by the EQUATOR system is discussed. The heliborne complex has a towed transmitter, and, raised above it on the same cable a towed receiver. The excitation signal contains both pulsed and harmonic components. In fact, there are two independent transmitters operate in the system: one of them is a normal pulsed domain transmitter, with a half-sinusoidal pulse and a small "cut" on the falling edge, and the other one is a classical frequency domain transmitter at several specially selected frequencies. The received signal is first processed to a direct Fourier transform with high Q-factor detection at all significant frequencies. After that, in the spectral region, operations of converting the spectra of two sounding signals to a single spectrum of an ideal transmitter are performed. Than we do an inverse Fourier transform and return to the time domain. The detection of spectral components is done at a frequency band of several Hz, the receiver has the ability to perfectly suppress all sorts of extra-band noise. The detection bandwidth is several dozen times less the frequency interval between the harmonics, it turns out thatto achieve the same measurement quality of ground response without using out-of-band suppression you need several dozen times higher moment of airborne transmitting system. The data obtained from the model of a homogeneous half-space, a two-layered model, and a model of a horizontally layered medium is considered. A time-domain data makes it easier to detect a conductor in a relative insulator at greater depths. The data in the frequency domain gives more detailed information about subsurface. These conclusions are illustrated by the example of processing the survey data of the Republic of Rwanda in 2017. The simultaneous inversion of data in frequency domain and time domain can significantly improve the quality of interpretation.

scholarly journals Broadband spectroscopy of astrophysical ice analogues

2019 ◽  
Vol 629 ◽  
pp. A112 ◽  
Author(s):  
B. M. Giuliano ◽  
A. A. Gavdush ◽  
B. Müller ◽  
K. I. Zaytsev ◽  
T. Grassi ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Time Domain ◽  
Complex Refractive Index ◽  
Far Infrared ◽  
Infrared Region ◽  
Thz Radiation ◽  
The Real ◽  
Thz Range ◽  
The Time Domain

Context. Reliable, directly measured optical properties of astrophysical ice analogues in the infrared and terahertz (THz) range are missing from the literature. These parameters are of great importance to model the dust continuum radiative transfer in dense and cold regions, where thick ice mantles are present, and are necessary for the interpretation of future observations planned in the far-infrared region. Aims. Coherent THz radiation allows for direct measurement of the complex dielectric function (refractive index) of astrophysically relevant ice species in the THz range. Methods. We recorded the time-domain waveforms and the frequency-domain spectra of reference samples of CO ice, deposited at a temperature of 28.5 K and annealed to 33 K at different thicknesses. We developed a new algorithm to reconstruct the real and imaginary parts of the refractive index from the time-domain THz data. Results. The complex refractive index in the wavelength range 1 mm–150 μm (0.3–2.0 THz) was determined for the studied ice samples, and this index was compared with available data found in the literature. Conclusions. The developed algorithm of reconstructing the real and imaginary parts of the refractive index from the time-domain THz data enables us, for the first time, to determine the optical properties of astrophysical ice analogues without using the Kramers–Kronig relations. The obtained data provide a benchmark to interpret the observational data from current ground-based facilities as well as future space telescope missions, and we used these data to estimate the opacities of the dust grains in presence of CO ice mantles.

EPR light beams and non-Gaussian quantum distributions in the time domain

2009 ◽  
Vol 6 (7) ◽  
pp. 577-580
Author(s):  
N. H. Adamyan ◽  
H. H. Adamyan ◽  
G. Yu. Kryuchkyan
Keyword(s):  
Time Domain ◽  
Non Gaussian ◽  
The Time Domain ◽  
Light Beams ◽  
Quantum Distributions
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