scholarly journals Vibration Analysis of a Bus’s Air Spring Suspension Subjected to Random Road Profile

2021 ◽  
Vol 3 (SI2) ◽  
pp. first
Author(s):  
TRAN Huu Nhan
Keyword(s):  
Vibration Analysis ◽  
Relative Displacement ◽  
Road Surface ◽  
Density Parameter ◽  
Spring Stiffness ◽  
Air Spring ◽  
The Road ◽  
Road Profile ◽  
Calculation Results ◽  
Road Surface Roughness

Vehicle dynamics model in type of 1/4 is used for vibration analysis under the effect of random road profile with different grades. The mathematical model to describe the used random road profile is able to change the type of investigated road grades by selecting the corresponding power spectral density parameter of the road grade according to the ISO 8608 standard. Random road profile is ivestigated in the range of frequency domain from 0 to 50 (Hz). The air spring stiffness and the damping coefficience are determined on the basis of reference to the practical vehicle. The variation of relative displacement amplitude of the suspension in the range of investigation domain is small, the air spring stiffness used in the calculation is constant. The obtained results corresponding to different grades of road surface roughness including displacement and acceleration parameters. Relative displacement is a parameter that aims to verify the ability to ensure safe working of the suspension, namely rattle spacing. Acceleration is used to evaluate the vehicle's comfort. Calculation results are analyzed as the basis for evaluating the influence of the air spring stiffness and road surface conditions on the comfort of the vehicle, as the basis for changing the air spring stiffness in accordance with adjusting the pressure of it according to the type of road profile quality.

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.

Optimal Active Control of Vehicle Suspension System Including Time Delay and Preview for Rough Roads

2002 ◽  
Vol 8 (7) ◽  
pp. 967-991 ◽  
Author(s):  
Javad Marzbanrad ◽  
Goodarz Ahmadi ◽  
Yousef Hojjat ◽  
Hassan Zohoor
Keyword(s):  
Ride Comfort ◽  
Three Dimensional ◽  
Suspension System ◽  
Road Surface ◽  
Vehicle Suspension ◽  
Control Force ◽  
Preview Control ◽  
The Road ◽  
Road Surface Roughness ◽  
Vehicle Suspension System

An optimal preview control of a vehicle suspension system traveling on a rough road is studied. A three-dimensional seven degree-of-freedom car-riding model and several descriptions of the road surface roughness heights, including haversine (hole/bump) and stochastic filtered white noise models, are used in the analysis. It is assumed that contact-less sensors affixed to the vehicle front bumper measure the road surface height at some distances in the front of the car. The suspension systems are optimized with respect to ride comfort and road holding preferences including accelerations of the sprung mass, tire deflection, suspension rattle space and control force. The performance and power demand of active, active and delay, active and preview systems are evaluated and are compared with those for the passive system. The results show that the optimal preview control improves all aspects of the vehicle suspension performance while requiring less power. Effects of variation of preview time and variations in the road condition are also examined.

A Simple Approach for Simulating the Road Surface Roughness Involved in Vehicle-Bridge Interaction Systems

2018 ◽  
Vol 18 (07) ◽  
pp. 1871009 ◽  
Author(s):  
Yao Zhang ◽  
Hai Sheng Zhao ◽  
Seng Tjhen Lie
Keyword(s):  
Surface Roughness ◽  
General Purpose ◽  
Simple Approach ◽  
Road Surface ◽  
The Other ◽  
Fe Modeling ◽  
The Road ◽  
Road Surface Roughness ◽  
External Forces ◽  
Small Elements

This paper presents an idea for modeling the road surface roughness in a vehicle–bridge interaction (VBI) system, by simulating it equivalently as two external forces each acting on the two subsystems of vehicle and bridge. Such an idea can be easily included in general-purpose commercial finite element (FE) software like ABAQUS and ANSYS. Compared with frequently used coupled and uncoupled FE models, the present approach is more convenient, since it does not require any self-developed FE codes. The other advantage is that it does not require very small elements in the FE modeling, as is the case with conventional approaches for simulating the irregularity in the profile of road surface roughness, which may be computationally inefficient.

scholarly journals A Two-Step Drive-By Bridge Damage Detection Using Dual Kalman Filter

2020 ◽  
Vol 20 (10) ◽  
pp. 2042006
Author(s):  
Jiantao Li ◽  
Xinqun Zhu ◽  
Siu-Seong Law ◽  
Bijan Samali
Keyword(s):  
Surface Roughness ◽  
Kalman Filter ◽  
Damage Detection ◽  
Interaction Force ◽  
Road Surface ◽  
Dynamic Responses ◽  
The Road ◽  
Stiffness Reduction ◽  
Bridge Damage ◽  
Road Surface Roughness

Drive-by bridge inspection using acceleration responses of a passing vehicle has great potential for bridge structural health monitoring. It is, however, known that the road surface roughness is a big challenge for the practical application of this indirect approach. This paper presents a new two-step method for the bridge damage identification from only the dynamic responses of a passing vehicle without the road surface roughness information. A state-space equation of the vehicle model is derived based on the Newmark-[Formula: see text] method. In the first step, the road surface roughness is estimated from the dynamic responses of a passing vehicle using the dual Kalman filter (DKF). In the second step, the bridge damage is identified based on the interaction force sensitivity analysis with Tikhonov regularization. A vehicle–bridge interaction model with a wireless monitoring system has been built in the laboratory. Experimental investigation has been carried out for the interaction force and bridge surface roughness identification. Results show that the proposed method is effective and reliable to identify the interaction force and bridge surface roughness. Numerical simulations have also been conducted to study the effectiveness of the proposed method for bridge damage detection. The vehicle is modeled as a 4-degrees-of-freedom half-car and the bridge is modeled as a simply-supported beam. The local bridge damage is simulated as an elemental flexural stiffness reduction. Effects of measurement noise, surface roughness and vehicle speed on the identification are discussed.The results show that the proposed drive-by inspection strategy is efficient and accurate for a quick review on the bridge conditions.

A Computerized Method for Dynamic Response of Vehicle-Bridge Interaction System under Various Conditions

2013 ◽  
Vol 639-640 ◽  
pp. 1214-1219
Author(s):  
Yao Xiao ◽  
Zheng Qing Chen ◽  
Xu Gang Hua
Keyword(s):  
Surface Roughness ◽  
Dynamic Effect ◽  
Integrated System ◽  
Road Surface ◽  
Dynamic Responses ◽  
Superposition Method ◽  
The Road ◽  
Computerized Method ◽  
Road Surface Roughness ◽  
The Impact

A computerized method is presented for computing the dynamic responses of bridges under moving vehicles. The bridge and vehicle are treated as integrated system and modal superposition method is applied to transfer the equation of motion into modal coordinate system. The road roughness/unevenness is also considered. The effects of different vehicle models, vehicle passing speed and road surface roughness on bridge dynamic responses are studied. The impact factor representing the dynamic effect of passing vehicle is calculated for different road surface roughness

Influence of road surface roughness on dynamic impact factor of bridge by full-scale dynamic testing

2005 ◽  
Vol 32 (5) ◽  
pp. 825-829 ◽  
Author(s):  
Young Suk Park ◽  
Dong Ku Shin ◽  
Tae Ju Chung
Keyword(s):  
Surface Roughness ◽  
Impact Factor ◽  
Road Surface ◽  
Roughness Coefficient ◽  
International Roughness Index ◽  
The Road ◽  
Surface Profiles ◽  
Road Surface Roughness ◽  
Dynamic Impact Factor ◽  
The Impact

Effects of road surface roughness on the dynamic impact factor of bridge are investigated through full-scale field loading tests under controlled traffic conditions. The dynamic time histories of displacements are obtained for twenty-five bridges on Korean highways. The impact factors of the bridges are evaluated by using the measured displacements. The road surface profiles of the twenty-five bridges are also measured at every 10 to 30 cm interval in the span direction. By using the measured road surface profiles, the international roughness index (IRI) and the roughness coefficients of the bridges are evaluated. The linear regression and correlation analyses are performed to obtain the coherences between the IRI and the roughness coefficient and between the IRI and the impact factor. The sample correlation coefficients between the impact factor and the IRI and between the impact factor and the roughness coefficient are calculated to be 0.61 and 0.62, respectively, showing a strong coherence between the road surface roughness and the impact factor.Key words: bridge, impact factor, road surface roughness, international roughness index, roughness coefficient.

scholarly journals A Mathematical Model to Evaluate the Impact of the Maintenance Strategy on the Service Life of Flexible Pavements

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Manuel Ruiz ◽  
Luis Ramírez ◽  
Fermín Navarrina ◽  
Mario Aymerich ◽  
David López-Navarrete
Keyword(s):  
Service Life ◽  
Fatigue Damage ◽  
Road Surface ◽  
Vertical Load ◽  
Dynamic Effects ◽  
Time Step ◽  
The Road ◽  
Road Profile ◽  
Effective Dynamic ◽  
Over Time

The structural failure of a flexible pavement occurs when the accumulated fatigue damage produced by all the vehicles that have passed over each section exceeds a certain threshold. For this reason, the service life of pavement can be predicted in terms of the damage caused by the passage of a single standard axle and the expected evolution of traffic intensity (measured in equivalent standard axles) over time. In turn, the damage caused by the passage of an axle depends on the vertical load exerted by the wheels on the pavement surface, as given by the technical standard in application, and the depths and mechanical characteristics of the layers that compose the pavement section. In all standards currently in application, the unevenness of the road surface is disregarded. Therefore, no dynamic effects are taken into consideration and the vertical load is simply given in terms of the static weight carried by the standard axle. However, it is obvious that the road profile deteriorates over time, and it has been shown that the increase in the pavement roughness, when considered, gives rise to important dynamic effects that may lead to a dramatic fall in the expected structural service life. In this paper, we present a mathematical formulation for the fatigue analysis of flexible pavements that includes the effects of dynamic axle loading. A pavement deterioration model simulates the sustained growth of the IRI (International Roughness Index) over time. Time is discretized in successive time steps. For each time step, a road surface generation model provides a profile that renders the adequate value of the IRI. A QHV (Quarter Heavy Vehicle) model provides the dynamic amplification function for the loads exerted on the road surface along a virtual ride. This function is conveniently averaged, what gives the value of the so-called effective dynamic load amplification factor (DLA); this is the ratio between the effective dynamic loading and the static loading at each time step. Finally, the damage caused by the passage of the standard axle can be evaluated in terms of the dynamic loading. The product of this damage times the number of equivalent standard axles gives the total fatigue damage produced in the time step. The accumulated fatigue damage at each moment is easily computed by just adding up the damage produced in all the previous time steps. The formulation has been implemented in the software DMSA (Dynamic & Maintenance Simulation App). This tool has been specifically developed for the evaluation of projects in applications for financing submitted to the European Investment Bank (EIB). DMSA allows for quantifying the expected structural service life of the pavement taking into account both the rise of the dynamic axle loads exerted by the traffic as the road profile deteriorates over time and the different preventive maintenance strategies to be taken into consideration.

Evolution of Pavement Winter Roughness

2005 ◽  
Vol 1913 (1) ◽  
pp. 137-147
Author(s):  
Nicolas Fradette ◽  
Guy Doré ◽  
Pascale Pierre ◽  
Serge Hébert
Keyword(s):  
Service Level ◽  
Road Surface ◽  
Longitudinal Profile ◽  
Dominant Factor ◽  
Quebec City ◽  
International Roughness Index ◽  
The Road ◽  
Deicing Salts ◽  
Road Profile ◽  
Main Factors

The functional service level of roads is quantified in terms of roughness. This parameter considers every road surface defect that causes passenger vehicle discomfort. Roughness is measured by a quality index, the international roughness index (IRI). Roughness gives an overall appreciation of road profile quality without, however, permitting a deeper analysis. The overall value of the IRI does not discriminate between the two main factors responsible for winter deterioration of roughness: the subgrade differential heave and crack heaving (winter tenting). Differential heave is the result of variability in frost susceptibility of subgrade. This phenomenon can be detected by isolating the long wavelengths produced at the road surface from the longitudinal profile. Crack heaving is a superficial phenomenon greatly influenced by the application of deicing salts. By isolating the short wavelengths from the profile, it is possible to highlight the influence of this phenomenon on deterioration. The goal of this research is to establish, with the use of a filtering technique of road profile, the contribution of these two main factors to winter deterioration of roughness on five road sections in the Quebec City, Canada, area. This study will then allow for the development of a tool to determine the dominant factor for longitudinal profile deterioration and therefore the use of the best technique to rehabilitate roads.

Damage Detection of Bridges Using Response of Vehicle Considering Road Surface Roughness

2015 ◽  
Vol 15 (03) ◽  
pp. 1450057 ◽  
Author(s):  
Zhenhu Li ◽  
Francis Tat Kwong Au
Keyword(s):  
Surface Roughness ◽  
Numerical Study ◽  
Road Surface ◽  
The Road ◽  
Damage Location ◽  
Girder Bridges ◽  
Optimal Value ◽  
Global Optimal ◽  
Vertical Accelerations ◽  
Road Surface Roughness

This paper presents a genetic algorithm (GA)-based method to identify the damage of girder bridges from the response of a vehicle moving over the bridge. The continuous wavelet transform-based method works when the surface is smooth but the identification becomes difficult when the road surface is rough. To deal with this problem, the identification process is formulated as an optimization problem and a guided GA is used to search for the global optimal value. The vertical accelerations of the vehicle running over the bridge at the intact and damaged states are used to identify the occurrence and location of the damage. Frequencies of the bridge at the intact and damaged states can be extracted from these responses, from which the frequency-based method can roughly estimate the possible locations of the damage. These locations are not unique as frequencies alone are insufficient to identify the damage location. However these initial results can be used to narrow down the search region on which the GA can focus. Numerical study shows that the strategy can identify the damage location for simply supported and continuous girder bridges even though road surface roughness and measurement noise are taken into account.

Tire-Road Interactions — Harmony or Conflict?

1989 ◽  
Vol 17 (1) ◽  
pp. 66-84
Author(s):  
A. R. Williams
Keyword(s):  
Rolling Resistance ◽  
Major Effect ◽  
Road Surface ◽  
Interactive Effects ◽  
Central Theme ◽  
Water Drainage ◽  
The Road ◽  
Truck Tires ◽  
Road Surfaces ◽  
Tire Wear

Abstract This is a summary of work by the author and his colleagues, as well as by others reported in the literature, that demonstrate a need for considering a vehicle, its tires, and the road surface as a system. The central theme is interaction at the footprint, especially that of truck tires. Individual and interactive effects of road and tires are considered under the major topics of road aggregate (macroscopic and microscopic properties), development of a novel road surface, safety, noise, rolling resistance, riding comfort, water drainage by both road and tire, development of tire tread compounds and a proving ground, and influence of tire wear on wet traction. A general conclusion is that road surfaces have both the major effect and the greater potential for improvement.

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