scholarly journals Vehicle model response in frequency domain

2020 ◽  
Vol 313 ◽  
pp. 00009
Author(s):  
Jozef Melcer ◽  
Veronika Valašková

The offered article deals with one of the possibilities of numerical analysis of the vehicle response in frequency domain. It works with quarter model of vehicle. For the selected computational model of vehicle it quantifies the Frequency Response Functions (FRF) of both force and kinematic quantities. It considers the stochastic road profile. The Power Spectral Density (PSD) of the road profile is used as input value for the calculation of Power Spectral Density of the response. Al calculations are carried out numerically in the environment of program system MATLAB. When we know the modules of FRF or the Power Response Factors (PRF) of vehicle model the calculation of vehicle response in frequency domain is fast and efficient.

2018 ◽  
Vol 211 ◽  
pp. 13001
Author(s):  
Veronika Valašková ◽  
Jozef Melcer

The vehicle - roadway interaction is actual engineering problem solved on many workplaces in the world. At the present time preference is given to numerical and experimental approaches. Vehicle designers are interested in the vibration of the vehicle and the forces acting on the vehicle. Civil engineers are interested in the load acting on the road. Solution of the problem can be carried out in time or in frequency domain. Road unevenness is the main source of kinematic excitation of the vehicle and therefore the main source of dynamic forces acting both on the road and the vehicle. The offered article deals with one of the possibilities of numerical analysis of the vehicle response in frequency domain. It works with quarter model of the vehicle. For the selected computational model of the vehicle it quantifies the Frequency Response Functions (FRF) of both force and kinematic quantities. It considers the stochastic road profile. The Power Spectral Density (PSD) of the road profile is used as input value for the calculation of Power Spectral Density of the response. All calculations are carried out numerically in the environment of program system MATLAB. When we know the modules of FRF or the Power Response Factors (PRF) of vehicle model the calculation of vehicle response in frequency domain is fast and efficient.


2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Kehui Ma ◽  
Yongguo Zhang ◽  
Xü Zhen

The road input model is very important in the analysis of vehicle ride comfort and handling stability. Based on the analysis of the relationship between the spatial frequency power spectral density and the time power spectral density of the road, the road signal generation model is established. The simulation is carried out under different vehicle speeds, and the B and C-level random road time excitation signals are generated. The power spectral density is used to compare the simulation results of the model with the road classification standard. The experimental results show that the results are accurate and can provide reliable excitation signals for vehicle control research.


Author(s):  
O Kropáč ◽  
P Múčka

Firstly, the effect of periodic components (undulation) appearing in the otherwise random longitudinal profile of road on standard indicators of random unevenness is studied. The power spectral density characterized by its parameters, i.e. the unevenness index and waviness, three band variances, and international roughness index are considered. Secondly, a series of simulation examples is given of the response of two planar vehicle models (a passenger car and a truck) traversing along the road with periodic components of longitudinal unevenness. The effects on people sitting in the vehicle and on the loading of the vehicle undercarriage and pavement structure are studied. The wavelengths of undulation and the running speeds that appear as most inconvenient are emphasized


Author(s):  
V.R. Deulgaonkar

Chassis mounted structure is a base component for shelters or containers mounted on heavy transport vehicles. When the vehicle is driven in rough terrains or during off-road transportation this structure has a significant role in protecting the sophisticated cargo and intelligent tracking systems placed inside the shelters. During off-road transportation or warhead conditions the vehicle is subjected to large unevenness in load due to road or soil irregularities in rough terrains, which causes vibrations to be induced in the vehicle. As the nature of vibrations induced in vehicle during travel on off-road or cross-country terrains is random and unpredictable, there is a concern to analyse the vibration response of chassis and chassis mounted structures is needed. Present work deals with vibration measurement and spectral analysis of a chassis mounted structure designed for off-road and commercial transport vehicles. The road profile on which the vibration measurement has been carried out includes paved road and cross-country terrain segments. The vibration measurement has been carried at three different vehicle speeds. Signal analysis procedure for the acquired test data is discussed. The chassis mounted structure under concern is intended to hold two shelters or containers. From the vibration measurement at critical locations, g-(RMS) and g-(peak) values for paved and cross-country roads have been found out. Power spectral density values have also been found on chassis and structure for the same transport situations. Major inferences include the evaluation of minimum and maximum g-values (peak and RMS) on chassis and chassis mounted structure. Power spectral density graphs are constructed from which the dominant frequency for both road profiles is found out.


Author(s):  
DASARI NAGARAJU ◽  
C. SHOBA BINDU

There are several worm attacks in the recent years, this leads to an essentiality of producing new detection technique for worm attacks. In this paper we present a spectrum based smart worm detection scheme, this is based on the idea of detection of worm in the frequency domain. This scheme uses the power spectral density of the scan traffic volume and its corresponding flatness measure to distinguish the smart worm traffic from background traffic. This scheme showed better results against the smart worms and also for the c-worm detection.


Author(s):  
J J Kim ◽  
H Y Kim

The note describes a simple method for evaluation of fatigue damage of structures in wide-band vibrations from response power spectral density data in the frequency domain. The method is applied to three sample cases and the results are compared with those of the damage calculation in the time domain.


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