Effect Of Road Roughness Research Articles

The Effect of Road Roughness on Travel Time

Travel time can be decreased by increasing the speed. Speed has a relationship with road roughness. In this research, there were forty different routes and travel time for each route was simulated by thirty different kinds of speed resulted from three categories of International Roughness Index : smooth, fair, and rough that range from 0.60 to 3.50. The routes were taken from daily operation – shipping activities which the starting point and the end point were from the main warehouse. The sequence of locations for each route in shipping activity was determined by the OptimoRoute software. The shortest, the mean and the longest travel time for each route was determined by Phython program. The results showed that travel time on smooth road was more efficient around 36.17% than fair road, more efficient around 57.19% than rough road, and the travel time on fair road was more efficient around 49.10% than rough road.

Fatigue life evaluation of bridge stay cables subject to monitoring traffic and considering road roughness

Bridge stay cables are susceptible to fatigue damage caused by cyclic traffic loads. However, the effects of road roughness on fatigue assessment are often ignored, even though it is an essential factor that amplifies the response in vehicle–bridge interaction (VBI) systems. To address this gap, this study proposes a framework for cable fatigue assessment considering road roughness. The framework includes the VBI analysis method accounting for road roughness, the generation of random traffic flow, and the evaluation of cable fatigue. A case study based on a typical cable-stayed bridge is conducted. The results show that the proposed framework can effectively and feasibly evaluate cable fatigue. It is found that a poor road surface can reduce the fatigue life of cables, causing up to 4.47 times more damage compared to smooth road conditions. The decline of cable fatigue life caused by road roughness is primarily concentrated on the cables around the main towers, while the other cables are less affected by road roughness. Based on the measured traffic volume under poor road surface conditions, the estimated minimum fatigue life of the cable is 64 years. Moreover, the study indicates that cable fatigue damage rises with increasing traffic volume. These findings highlight the importance of considering road roughness and maintaining bridge decks to prevent the reduction of cable fatigue life.

Estimation of the Friction Behaviour of Rubber on Wet Rough Road, and Its Application to Tyre Wet Skid Resistance, Using Numerical Simulation

Tyre wet skid resistance greatly affects vehicle safety, and it is dependent on the frictional behaviour at the tyre–road interface; however, the currently available numerical models, using the finite element method, either neglect the road roughness or obtain the rightness using expensive computed tomography scans, rendering them inefficient and complex. This study aims to present an estimation method of rubber slides on a rough road, to study tyre wet skid resistance. A three-dimensional rough road model was established, using the harmonic superposition method; the sealing effect of the water film on a wet road was modelled in terms of the pseudo-hydrodynamic bearing effect; the contact pressure, hysteresis friction, and water film hydrodynamic lift force were calculated. Subsequently, a friction model was established that accounted for the road surface morphology, tyre properties, sliding speed, and contact pressure. The accuracy of the friction model was experimentally validated, using the published experimental results. The friction model was then adopted, to conduct a study of the wet skid resistance of a 205/55R16 tyre with two different tread patterns. The simulation results were consistent with the experimental results of braking distance on a wet road. Finally, the effects of road roughness, tread rubber, load, and inflation pressure on wet skid resistance were carried out and analysed. The works in this paper have important significance and practical value for the development of high-performance tyres.

The Use of a Movable Vehicle in a Stationary Condition for Indirect Bridge Damage Detection Using Baseline-Free Methodology

The use of an instrumented scanning vehicle has become the center of focus for bridge health monitoring (BHM) due to its cost efficiency, mobility, and practicality. However, indirect BHM still faces challenges such as the effects of road roughness on vehicle response, which can be avoided when the vehicle is in a stationary condition. This paper proposes a baseline-free method to detect bridge damage using a stationary vehicle. The proposed method is implemented in three steps. First, the contact-point response (CPR) of the stationary vehicle is computed. Secondly, the CPR is decomposed into intrinsic mode functions (IMFs) using the variational mode decomposition (VMD) method. Finally, instantaneous amplitude (IA) of a high frequency IMF is computed. The peak represents the existence and location of the damage. A finite element model of a bridge with damage is created. The results show that the method can identify the damage location under different circumstances, such as a vehicle with and without damping, different speeds of the moving vehicle, different sizes of damage, and multiple damage. A higher speed was found to provide better visibility of damages. In addition, smaller damage was less visible than wider damage.

Impact of Dynamic Loading on Confined Asphalt Concrete Surface

The behavior of asphalt concrete (AC) is highly dependent on the temperature and frequency of loading. Traditionally, the modulus of AC materials is characterized by performing creep recovery or complex modulus tests without considering the impact of the lateral confinement level. Because traffic-induced loading generates a multi-axial stress state within the pavement structure, quantifying the effect of the lateral confinement on the global AC behavior becomes a necessity. Studies have shown that the responses of dense-graded AC mixtures are highly dependent on confinement levels, especially at low frequencies and high temperatures. In this study, a constitutive model was developed for confinement-dependent linear viscoelastic (LVE) behavior. The model was then incorporated into finite element pavement models using a user material subroutine. The numerical pavement models were used to quantify the impact of lateral confinement on pavement critical responses under various temperature profiles and tire loadings. Multiple loading levels were selected to consider the effect of road roughness on tire loading amplification. Results show that the effect of confinement depends on the relative position of the moving load. Vertical strains under the tire are significantly reduced by confinement. Finally, the maximum percentage decreases in the compressive and vertical shear strains from incorporating the confinement-dependent LVE model were found to be 31% and 17.5%, respectively, for the highest load–temperature combination.

Establishment of an Eleven-Freedom-Degree Coupling Dynamic Model of Heavy Vehicle-Pavement

Considering the actual situation of moving vehicles acting on road surfaces, a dynamic model of a heavy vehicle–road coupling system was established based on the traditional vehicle–road vibration model. Firstly, a seven-degree-of-freedom vehicle model was established, and the vibration characteristics of the road subsystem were considered part of the whole system. The excitation effect of road roughness on the vehicle model was considered, and the dynamic model of the coupling system was finally obtained by combining the displacement compatibility principle of the contact relationship between the wheels and the road surface. The results show that the maximum bending value of the surface course reaches 2.37 mm. The maximum shear stress in the middle part of the surface course is 43,858 Pa. The vertical dynamic stress in the middle part of the surface course is larger, reaching 119,373 Pa, while the value of the vertical dynamic stress in the subgrade is much smaller, reaching 5824 Pa. The coupling dynamic model can reflect the relationship between the moving vehicle and the road and the dynamic performance, which not only provides theoretical support for the design parameters of heavy-duty vehicles but also provides a reference for the design of road durability.

Effects of Road Roughness, Aerodynamics, and Weather Conditions on Automotive Wheel Force

Taking road roughness, aerodynamics, and weather conditions, viz temperature and humidity, into consideration, the force applied to the wheel of a half-vehicle model traveling at constant speed has been calculated. A D-type rough horizontal road according to ISO 8606 evaluations was chosen for the experiment and the surface profile of which was measured by means of a topographic camera of Leica series to acquire discrete data to model the road roughness. The data have been converted from discrete points into smooth continuous linear functions with quadratic blends, because of the fact that the governing differential equations of motion of the vehicle model require the road roughness and the time rate of change thereof. The line of action of wind or aero-dynamical force applied to the vehicle model has been assumed to pass through the vehicle mass center. The vibrations of the half-vehicle model have been found via the Runge-Kutta method. DoE (Design of Experiments) has been used to investigate the effects of air temperature and humidity on the front and rear wheels. It was found that the value of force applied to the front wheel is far greater than that applied to the rear wheel (about 16.5%). Also, the role of the air temperature is much more effective on the wheel force than the air humidity. Moreover, the force of the front wheel is directly related to the values of weather parameters and the force of the rear wheel is inversely related to it.

A Spline Method based on the Crack Induced Deflection for Bridge Damage Detection

This paper proposes a novel method for damage detection on a simply supported beam subjected to a moving mass using multiple vibration data measured from a vehicle-bridge interaction (VBI) model. It is shown first that the integral of the difference between the deflection time history of the healthy and damaged beam reaches a local maximum at the location of the crack. As such, the integral of the difference between the vibration time history of the healthy and damaged beam at some dense points on the beam is required. However, practically the number of measured points is limited. Therefore, the data from VBI measured at a limited set of points have been interpolated at each time instant to estimate the deflection of other locations on the beam. It has been demonstrated through several simulations that the proposed method can detect both the location and severity of damage on the beam while considering the interaction between the moving mass and the bridge, as well as the effect of road roughness. It is also shown that the proposed method is fairly robust to noise in both damage localisation and quantification.

Potential Energy Savings by Reducing Rolling Resistance of Dutch Road Pavements

The current study focuses on options to improve vehicle energy efficiency by reducing rolling resistance on Dutch national highways. Different studies of pavement materials have been evaluated, and models have been compared to experimental data to review rolling resistance indicators. The study shows that texture parameters MPD (mean profile depth) and RMS (root mean square) are relevant indicators for rolling resistance, whereas the effect of road roughness (IRI) is found to be larger than indicated in the evaluated models. The effects of other wavelength regions, texture orientation, and road wear need further investigation. The rolling resistance assessment shows that single-layer porous asphalt concrete (PAC) with aggregate size 6/16 (which is most currently used on Dutch highways) has rolling resistance levels that are 8-10% higher than the levels of double-layer porous asphalt concrete (DPAC) with aggregate size 2/6. Switching to DPAC 2/6 for highways would result in energy savings of 2-2.5%. These calculations are based on estimations and results with high uncertainty and should therefore be taken as a rough estimate of the potential energy savings. Further research is recommended to further refine and validate the results of this study.

Numerical Simulation of Vibration of Highway Cable-Stayed Bridge with Steel Arch Tower due to Moving Vehicle Loads

Recently, with the development of highway traffic cause and long-span bridges, the vibration performances of highway bridges due to moving vehicle loads have attracted more and more attention. The vibration of a cable-stayed bridge with steel arch tower subjected to vehicle loads was studied in this paper. Firstly, the dynamic model of vehicle and finite element model of bridge were built and the dynamic differential equations of vehicle model and vehicle-bridge coupled system were derived. Then road roughness was simulated using superposition method of trigonometric series. Finally, the bridge responses caused by vehicle loads were calculated numerically. Furthermore, the effects of road roughness, vehicle velocity and bridge damping on bridge responses and their dynamic amplification factors were studied. The results and conclusions of present study are expected to be useful for the future revision of bridge design codes and maintenance and management of bridge.

Effect of Road Roughness on Capacity of Two-Lane Roads

The Highway Capacity Manual (2000) states that the capacity of a two-lane rural highway under ideal conditions is 3200 passenger car unit per hour for both directions combined. The ideal conditions as given in the manual do not include the riding quality of a road, which deteriorates with time. The present study has shown that the capacity of a two-lane rural road is also affected by the road roughness. Data collected on the roughness and free-flow speed of cars and heavy vehicles at a length of 55 km on three highways in India was used to establish the relationship between these two variables. Further, speed–volume data collected at eight different sections of two-lane roads were analyzed and the effect of road roughness on capacity was evaluated.

FACTORS INFLUENCING THE EFFICIENCY OF ROAD DRAINAGE GRATINGS.

This paper presents the results of an industry-supported study conducted at Oxford Brookes University to explore the factors influencing the hydraulic efficiency of road drainage gratings. A number of full-size model gratings with varying geometric characteristics have been tested on a model road surface, and an assessment made of the influence of grating length and width, horizontal and vertical bar alignment, depth of depression, road slope, crossfall, and approaching flow width. The effect of these variables is illustrated graphically. In addition, the effect of road roughness is illustrated using previously published data. Grating width is found to be of greater importance than length, and gratings with bars orientated parallel to the kerb are shown to be more efficient than those with bars set at right angles to the kerb. Altering the alignment of the bars in the vertical plane reduces splashing and increases efficiency. Depressing a grating is found to increase efficiency, and increasing road slope, crossfall and flow width approaching a grating, reduces efficiency. The discussion is supplemented using other researchers' findings. (A)

The Effect of Road Roughness on Vehicle Behavior

The Effect of Road Roughness on Vehicle Behavior