Influence of Road-Surface Roughness on Vehicle Operating Costs: Reviewing the Evidence from Developing Countries

2009 ◽  
pp. 416-416-14 ◽  
Author(s):  
R Harrison
Keyword(s):  
Surface Roughness ◽  
Developing Countries ◽  
Road Surface ◽  
Operating Costs ◽  
Road Surface Roughness

scholarly journals A Frequency Compensation Algorithm of Four-Wheel Coherence Random Road

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Jun Feng ◽  
Xinjie Zhang ◽  
Konghui Guo ◽  
Fangwu Ma ◽  
Hamid Reza Karimi
Keyword(s):  
Surface Roughness ◽  
Coherence Function ◽  
Road Surface ◽  
Domain Model ◽  
Important Influence ◽  
Frequency Compensation ◽  
The Road ◽  
Compensation Algorithm ◽  
Left And Right ◽  
Road Surface Roughness

The road surface roughness is the main source of kinematic excitation of a moving vehicle, which has an important influence on vehicle performance. In recent decades, random road models have been widely studied, and a four-wheel random road time domain model is usually generated based on the correlation of the four-wheel input, in which a coherence function is used to describe the coherence of the road input between the left and right wheels usually. However, during our research, there are some conditions that show that the road PSD (power spectral density) of one wheel is smaller than the other one on the same axle. Actually, it is caused by the uncorrelation between the left- and right-wheel road surface roughness. Hence, a frequency compensation algorithm is proposed to correct the deviation of the PSD of the road input between two wheels on the same axle, and it is installed in a 7-DOF vehicle dynamic study. The simulation result demonstrates the applicability of the proposed algorithm such that two-wheel road input deviation compensation has an important influence on vehicle performances, and it can be used for a control system installed in the vehicle to compensate road roughness for damper tuning in the future.

Identifying Mode Shapes of Girder Bridges Using Dynamic Responses Extracted from a Moving Vehicle Under Impact Excitation

2017 ◽  
Vol 17 (08) ◽  
pp. 1750081 ◽  
Author(s):  
Z. Q. Qi ◽  
F. T. K. Au
Keyword(s):  
Surface Roughness ◽  
Natural Frequency ◽  
Road Surface ◽  
Measurement Noise ◽  
Dynamic Responses ◽  
Impact Excitation ◽  
Mode Shapes ◽  
Moving Vehicle ◽  
Girder Bridges ◽  
Road Surface Roughness

The mode shapes of a bridge are important modal properties for many purposes, such as damage detection and model updating. Traditional methods for constructing mode shapes often require installation of instruments on the bridge for collection of dynamic responses. However, these methods are not only costly but also inconvenient. Therefore, a method is developed for constructing the mode shapes of girder bridges using the dynamic responses extracted from a moving vehicle under impact excitation. This paper reports some numerical simulations based on finite element modeling. First, the dynamic responses of a moving vehicle under impact excitation are generated for simulation. Then the component response associated with each natural frequency of the bridge is extracted by using a suitable filter. Finally, the mode shape associated with each natural frequency identified is constructed from the extracted component response and its Hilbert transform pair. The proposed method uses only the information measured from the moving vehicle, which acts both as a sensor and an exciter. Moreover, the additional impact excitation on the vehicle helps to excite the bridge. This helps to improve the accuracy by overcoming the adverse effects of measurement noise and road surface roughness. The effects of measurement noise, road surface roughness and vehicle speed on the accuracy of results are evaluated. A numerical study is presented to verify the feasibility of the proposed method.

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