Road Surface Roughness Research Articles

Comparison of pavement morphology in the Povazsky Chlmec tunnel before and after maintenance

Roughness is one of the most important variables affecting the safety of vehicles on the road. Insufficient road surface roughness can lead to loss of vehicle handling, which in turn leads to an increased likelihood of an accident. Roughness as a variable parameter of pavement must be monitored during the life cycle of the road to ensure its operational capability. The article deals with determining the roughness characteristics using three different devices - TWO, British pendulum tester, and SRS. This is the road surface on the section of the D3 highway in the Povazsky Chlmec tunnel, where road maintenance was planned. The main goal was to compare the quality of the pavement before and after road maintenance, where an increase in the coefficient of skid friction was found after the maintenance of the road.

农田地面与沥青路面不平度特征的测试、分析与比较

Measuring and analysing the roughness of agricultural field and road have great significance for studying the characteristics of tractor dynamic response. This study was designed to analyse and compare the roughness characteristics of agricultural field and asphalt road profiles. A profiling apparatus was developed to measure field and road surface profiles of parallel tracks. The profile measurements were conducted in a grass field, a corn stubble field, a harvested potato field and on an asphalt road. The root mean square value and two spectrum parameters of surface profiles were calculated and analysed to investigate the roughness characteristics of fields and asphalt road. The results of the study indicate that for the values of the agricultural field and asphalt road surface roughness, waviness and roughness index are both positive associated with the root mean square value. Most of the waviness values of all measured field profiles were less than 2 with the average of 1.8, while the waviness values of all measured asphalt road profiles were greater than 2 with the average of 2.08. The roughness of both field and asphalt road profiles can be distinguished by the power spectral density fitting method. However, it has better performance in characterizing asphalt road profiles than characterizing field profiles with the power spectral density fitting method.

Static and Model Analysis on Pneumatic Suspension by using Ansys Software

During the tractor movement, with being attached to the hitch-system working equipment over Rough road surfaces oscillation of the machine take place. These oscillations are a reason of pressure pulsations in the hydraulic hitch-system. The pressure pulse reduction in the tractor Hitch-system is important for increasing of the system components lifetime. Pressure oscillation damping in the tractor hydraulic hitch-system can reduce overall system oscillations and improve the driving control. The design of spring in suspension system is very important. In this project a shock absorber is designed and a 3D model is created using CATIA V5 R20. The model is also changed by changing the thickness of the spring. Structural analysis and modal analysis are done on the suspension system by varying material for spring, Spring Steel and Beryllium Copper. Analysis done in ANSYS 14.5. The analysis is done by considering loads, bike weight, single person and 2 persons. Structural analysis is done to validate the strength and modal analysis is done to determine the displacements for different frequencies for number of modes. Comparison is done for two materials to verify best material for spring in suspension system.

Research on the International Roughness Index Threshold of Road Rehabilitation in Metropolitan Areas: A Case Study in Taipei City

The International Roughness Index (IRI) is the standard scale for evaluating road roughness in many countries in the world. The Taipei City government actively promotes a Road Smoothing Project and plans to complete the rehabilitation of the main and minor roads within its jurisdiction. This study aims to detect the road surface roughness in Taipei City and recommend appropriate IRI thresholds for road rehabilitation. A total of 171 asphalt concrete pavement sections in Taipei City with a total length of 803.49 km were analyzed and compared by IRI. The longitudinal profile of the detected road sections was measured using an inertial profiler. The statistical analysis showed that the IRI value prior to road leveling was mainly distributed between 5 and 8 m/km, while the IRI value after road leveling was mainly distributed between 3 and 4.5 m/km. This confirms that the implementation of the Road Smoothing Project has a significant effect on improving road smoothness. Moreover, based on the analysis results, it is recommended that the IRI threshold value for road rehabilitation in Taipei City be set at 4.50 m/km.

Crowdsourcing-Based Road Surface Evaluation and Indexing

Continuous monitoring of road surface quality is necessary to maintain high functionality of the entire road networks and allow users to perceive road roughness. Although several fundamental methods have been used to evaluate road roughness by employing smart probe cars, the accuracy of these methods is affected by factors, such as vehicle speed, sensor positions, and vehicle suspension systems. Also, the long-term application of these methods to the entire road network is also limited due to the high cost. Further, the widely used roughness indices do not reflect road users’ perception about road roughness as these indices are also affected by the accuracy of the roughness evaluation methods. Therefore, we propose a crowdsourcing based road roughness evaluation model which uses power spectral density accompanied with blind source separation technique to eliminate the vehicle effects. We also propose a road surface ranking based on majority voting algorithm for comparing roads based on their surface quality. Finally, the road surface roughness index is derived to widen the range of quality scale and capture roughness at fine granularity. The models are tested by real world experiments on different roads in Taiwan. The results show that the proposed model can accurately measure the roughness of roads, rank these roads and index them accordingly in a way that shows tiny differences in the road surface quality.

Modelling and Control of Air Bellow based Active Suspension System

This paper presents a complete design and simulation of active suspension actuated using pneumatic air bellow. The electronic controlled active suspension will control all vertical force acting from road surface by regulating the air mass of bellow. Quarter car active suspension is modelled and analysed using Matlab-Simulink. The output of designed active suspension system is simulated under standard road input that gives the response of the suspension to varied roughness of road surface. From the results it is evident that proposed active suspension system can suppress more than 60% than standard passive suspension system.

Control of the air suspension system of semi-trailer trucks to enhance the road friendliness

An air suspension system of semi-trailer trucks controlled by semi-active fuzzy logic control is proposed and researched to reduce the dynamic load coefficient (DLC) of the wheel axles. A dynamical model described by a nonlinear system with 7-DOF of the vehicle and a Simulink program developed in Matlab software are applied to simulate the DLC values under different operation conditions. The fuzzy control is then applied to control damping coefficients of the air suspension system. The obtained results show that semi-active air suspension of semi-trailer truck is overall superior to passive air suspension. The DLC values are also significantly decreased in all cases of the road surface roughness, over a range of vehicle velocity and the different loaded conditions. Particularly, under vehicle fully loaded condition, the DLC value of the tractor driver is greatly reduced by 27.4 % at speed of 27.5 m/s on the ISO level B road.

DYNAMIC ANALYSIS OF COMPOSITE MULTI I-GIRDERS BRIDGE USING FINITE ELEMENT METHOD

Three dimensional finite element models are developed to deal with the bridge-vehicle interaction problem of simply supported composite multi I-girders bridge. The bridge is modeled by using ANSYS 15.0 program with solid and shell elements to represent concrete and steel members, respectively. AASHTO HL-93 truck is idealized as 3D non-linear model consisting of five lumped masses connected by rigid beams and supported by spring-dampers. The separation between the tires and road surface and surface roughness condition are simulated by Gap and actuator elements, respectively. The road surface roughness profiles are generated from power spectral density (PSD) and cross spectral functions. The models used are capable to take all bridge and vehicle responses into consideration with no limitations on the complexity of the models. The dynamic responses of the multi I-girder bridge are investigated under conditions of various loading positions, roughness classes, vehicle speeds, and bump height. The dynamic behaviors are presented in terms of Dynamic Amplification Factors (DAF). The results show the girder that itself supporting the moving vehicle has lower value of DAF because of higher static responses. A 45 km/hr vehicle speed provides higher DAF value. The bump heights have significant effect on DAFs for bridge with short span.

Improving the Accuracy of Road Surface Distinction Based on Reflection Intensity Variations Using Ultrasonic Sensor

Fall cases in the daily lives of elderly people are increasing owing to the progressing aging society problem. The falls of elderly people usually have correlations with poor physical conditions and judgment and cause severe consequences. To prevent elderly people from falling, a movement support system was developed in our previous research. The system employs a reflection intensity value obtained by an ultrasonic sensor to identify the type of road surface and sounds an alert when the road surface is dangerous and may cause the user to slip or fall. However, the conventional method does not solve the problem of low detection rate on rough road surfaces without considering the variation in the reflection intensity due to the change in the shape of the road surface. In this paper, the variation in the reflection intensity is measured by investigations at multiple types of locations. The variation in the reflection intensity is introduced as a parameter to improve the road surface identification accuracy. The effectiveness of the proposed method in this paper is verified by experiments on four types of road surfaces. The necessary number of reflection intensity samples for road surface identification is also discussed.

Assessment of the Road Surface Condition with Longitudinal Acceleration Signal of the Car Body

On the basis of road tests, the authors assessed the feasibility of the vehicle body acceleration values for the purposes of assessing road surface characteristics in terms of its roughness. Short-term Fourier Transform (STFT) was used for the analysis of the recorded signal. The spectra obtained in successive frequency bands demonstrate the amplitudes originating from the natural vibrations of the rolling wheel and forces resulting from the interaction with the road roughness. The article focuses on the relationships between the road roughness and the ratios of individual amplitudes in a specific frequency band of the vehicle body acceleration values. Amplitude values derived on the basis of successive windows were averaged for analogous, arbitrarily assumed local frequency bands. The value characterizing the road surface condition provided the information regarding the mean amplitude value in specific frequency ranges depending on the instantaneous velocity of the car body and the condition of the road surface on which it was moving. In cases where the road was free of any visible roughness, the obtained mean amplitude value in the analyzed spectrum window, for the adopted vehicle velocity range from 50 km h to 100 km/h, did not exceed 0.02 m/s2. It was also demonstrated that the road surface roughness leads to an increase in the mean amplitude value from 0.07 m/s2 to 0.16 m/s2.

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

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.

Predicting the fatigue life of an automotive coil spring considering road surface roughness

The current work aims to determine the life of an automotive coil spring due to road surface roughness. Strain gages were installed at the critical and the non-critical areas of the coil spring and driven the vehicle on road surfaces at different speeds. Driving the vehicle on the rural road resulted in 88.4% and 83.9% decreases in the useful life in comparison to the highway and the urban roads, respectively. It concluded that, a road surface with bumps, holes and uneven tar patch as well as driving behavior like turns, speed changes, accelerations and brakes affects the car component life significantly.

Durability of lithium-ion 18650 cells under random vibration load with respect to the inner cell design

Lithium-ion batteries undergo random vibrations in automotive applications, for example due to rough road surfaces. So far, no investigation based on random vibration has considered the influence of the inner cell design and the influence of cyclic aging on vibration durability. Therefore, in this study, 18 different 18650 cell types from seven different manufacturers are tested, using two random vibration load profiles. The applied vibration profiles are the random profile according to the standard SAE J2380 and another upscaled, more severe profile. The SAE J2380 test is carried out using both new and electrically pre-cycled cells. All cell types are analyzed by computed tomography in terms of their inner design with a focus on inner mandrel, spacer and tab design. The performance of the cells is checked in terms of capacity, electrochemical impedance spectroscopy and post-vibration computed tomography. None of the cells shows significant electrical performance degradation due to the vibration. Post-vibration computed tomography reveals mechanically damaged negative current collector tabs inside of two cell types due to a loose mandrel in the case of the upscaled profile. These cell types have the lowest ratio of mandrel diameter to inner jelly roll diameter, emphasizing the importance of the inner cell design for vibration durability.

The Effect of Road Surface Roughness to Recommended Speed of Vehicles

Road safety is one of the major concerns of the transportation system planners and managers in any nation. The principle goal of road safety is to reduce the frequency and severity of traffic accidents. The design and manufacturing of high-quality road directly play an important role in achieving better road safety. This research presents the model describing the relationship between road surface roughness with the vehicle’s recommended safe velocity. The result shows that the road surface roughness measured by the International Roughness Index (henceforth IRI) is indirectly proportional to the vehicle’s recommended safe velocity. In particular, if the recommended safe velocity is 100 km/h, the surface roughness IRI should not exceed 1.9 m/km. An implication of this is the possibility that using the simulation on MATLAB Simulink software should have the appropriate IRI concerning the designed speed.

Fatigue Life Assessments of the AISI 1513 Carbon Steel Subjected to Road Surface Strains

The purpose of this work was to predict the fatigue life of the AISI 1513 carbon steel due to the strains measured at a vehicle's lower arm. The strain signals were acquired using a strain gauge installed at the lower arm, and then the car was driven at various road surfaces. On the smooth road surface, the car was driven at a speed of > 70 km/h and on the rough road surface, at a speed of < 20 km/h. The results show that when the vehicle was driven on the rough road, the lower arm received higher stress, which provided a shorter fatigue life. The contour of the road surfaces provided a vertical load, directly working the lower arm and reducing the load vertically. The fatigue life for the rough road surface was 13,050 cycles to failure. This value was 91,195% lower than the fatigue life on the smooth road surface.

Design Life Correlation of Axle Housings with Experimental Investigations and Failure Analysis to Overcome Manufacturing Process Influences by Surface Finish Improvements

The present study deals with the design life variation of axle housings with experimental investigations. The detailed failure analysis has been carried out on the influence of various manufacturing process. It is found that significant results are achieved due to surface finish improvements. Life of axle housing at design stage is estimated using road surface roughness value and indoor bending test method. The conditions of road roughness are varied drastically due to the terrain in which vehicle operates. The estimation of dynamic forces acting on axle for a typical terrain is extremely difficult, so actual strain values were measured at suspension mounting zones in the axle assembly for various road roughness and payload conditions. Similarly, component level estimation is calculated for indoor bench test conditions. Life estimates using design intended surface roughness and tensile strength measured at raw material in plate condition does not reveal any failure. But premature failure of the actual component during experimental testing occurred, which does not match to design calculations. Failure investigation at the cracked zone reveals manufacturing processes have altered the fatigue characteristic of housing plate. The key influencing factor is the surface finish deterioration of axle housing plates from the design intended value of 10 to 22 µm after press forming. Surface roughness creates micronotches leading to crack initiation on the other hand the tensile strength of the formed component is being altered during hot working from 610 to 500 MPa. On re-estimating, the design life considering the influence of manufacturing process results are closer to the experimental values with altered SN curve. Several iterations has been carried out with different surface finish values to analyze the failure, keeping the tensile losses due to hot working in the component to be constant. It is found that surface finish improvement up to 3 µm will make the axle housing to meet acceptance life, which can be achieved by using abrasive or pressurized sand blasting after forming process. Alternatively, for plates having tensile strength up to 620 MPa, surface finish can be lowered as low as 80 µm and still life meets acceptance. Lowering surface finish value favors manufacturer to choose low-cost manufacturing process.

Modelling and analysis of vibration on power electronic module structure and application of model order reduction

Modelling and analysis of vibration of an IGBT power electronic module (PEM) structure were undertaken. PEM structure considered in this study was without molding compound and wirebonds. The most critical resonant frequency was identified by modal analysis. At the critical frequency of 1345 Hz, for the vertical displacement of the base excitation, subsequent stress distribution on the PEM structure was analysed. Concurrent vibration and thermo-mechanical fatigue loads on the reliability of PEM structure solder interconnects were also estimated by widely used linear damage superposition approach. It was concluded that the at critical resonant frequency the vibration induced damage is more severe than the thermo-mechanical fatigue loading. In addition, a quarter car model (QCM) was used to mimic the dynamic interaction between the rough road surface and an electric vehicle (EV) in order to analyse the road surface roughness induced excitation on the PEM structure in the engine compartment. Stress and strain distribution on the PEM structure due to road surface roughness were analysed. Furthermore, three Krylov subspace based model order reduction (MOR) techniques were applied to the resulting dynamic system in vibration analysis. Due to the limits on computing resources, a submodel was utilized for MOR analysis. Within the three MOR techniques, Passive Reduced order Interconnect Macromodeling Algorithm (PRIMA) MOR technique performs better than the other techniques. Computational time ratio between reduced system iteration and the full system iteration is 1: 53.

Study on Passenger Comfort Based on Human–Bus–Road Coupled Vibration

Nowadays, the comfort of drivers and passengers is drawing more and more attention. The interaction between vehicles and the asphalt road can cause coupled vibration and reduce the comfort of passengers. Therefore, the research on human–vehicle–road coupled vibration and the comfort of passengers is of great importance. In this paper, the three-dimensional human–bus–road coupled vibration system is established, including the bus model, the parallel biomechanical human model with 2 degrees-of-freedom (DOF), and road surface roughness condition. The proposed coupled model was then used to study the dynamic response of the system and the comfort evaluation of the human body. In the comfort evaluation, the annoyance rate based method was proposed to consider the randomness of passenger vibration, the difference of the psychosensory vibration, and the fuzziness of evaluation indicators. Compared to the fuzzy evaluation based on the ISO 2631 standard, the proposed annoyance rate based method gives a quantitative evaluation of human comfort. Not only the degree of comfort can be evaluated, but the percentage of people feeling uncomfortable can also be obtained. Finally, parametric studies were conducted to investigate the effects of road surface roughness, interlayer bonding condition, bus weight, bus speed, and sitting position. It is found that the road surface roughness has the most significant effect on human comfort.

Effect of vehicle speed and road surface roughness on the impact factor of simply supported bridges due to IRC Class A and B loading

Indian Road Congress (IRC)-06 specifies consideration of impact factor for dynamic analysis of bridge loaded with Class A and Class B vehicles. As per IRC-06 specifications, the impact factor is estimated based only on the span length of the bridge. In the present study, the effect of vehicle speed, road surface roughness condition and span length of the bridge on the impact factor is investigated. The dynamic response of a simply supported bridge loaded with IRC Class A and Class B vehicle loads are considered for the study. For simplifications, the vehicles are idealized as a series of moving mass spring damper system. The interaction between the bridge and vehicle is accomplished by coupling the equation of motion using the interaction force at the contact point of the wheel and bridge. The coupled equation of motion is solved using Newmark’s beta method. The model is validated using past available literature. The vehicle is considered to move at a consistent speed between 20 and 100 km/h. The excitation caused due to the presence of road surface roughness at various vehicle speeds on the bridge response with span lengths varying between 20 and 100 m is investigated. Parametric studies are also conducted using frequency ratio. From the studies, it is observed that the response of the bridge subjected to IRC Class A vehicle is 40% higher than the response of the bridge subjected to IRC Class B vehicle. It is also observed from the parametric study that, the bridge response becomes critical when the vehicle moves at resonance speed and the amplitude increases with deterioration of road surface condition. The results of the impact factor study show that IRC-06 specifications underestimate the response of the bridge for high speed moving vehicles under different road surface conditions. The findings of this study can be utilized to update the IRC specifications at the time of analysis and design of both short and as well as long-span highway bridges.

Bridge modal identification using acceleration measurements within moving vehicles

Vehicles commuting over bridge structures respond dynamically to the bridge’s vibrations. An acceleration signal collected within a moving vehicle contains a trace of the bridge’s structural response, but also includes other sources such as the vehicle suspension system and surface roughness-induced vibrations. This paper introduces two general methods for the bridge system identification using data exclusively collected by a network of moving vehicles. The contributions of the vehicle suspension system are removed by deconvolving the vehicle response in frequency domain. The first approach utilizes the vehicle transfer function, and the second uses ensemble empirical modal decomposition (EEMD). Next, roughness-induced vibrations are extracted through a novel application of second-order blind identification (SOBI) method. After these two processes, the resulting signal is equivalent to the readings of mobile sensors that scan the bridge’s dynamic response. Structural modal identification using mobile sensor data has been recently made possible with the extended structural modal identification using expectation maximization (STRIDEX) algorithm. The processed mobile sensor data is analyzed using STRIDEX to identify the modal properties of the bridge. The performance of the methods are validated on numerical case studies of a long single-span bridge with a network of moving vehicles collecting data while in motion. The analyses consider three road surface roughness patterns. Results show that for long-span bridges with medium- to high-ongoing traffic volume, the proposed algorithms are successful in extracting pure bridge vibrations, and produce accurate and comprehensive modal properties of the bridge. The study shows that the proposed transfer function method can efficiently deconvolve the linear dynamics of a moving vehicle. EEMD method is able to extract vehicle dynamic response without a priori information about the vehicle. In addition, proposed identification methods provide secondary information about the roughness pattern and the vehicle. This study is the first proposed methodology for complete bridge modal identification, including operational natural frequencies, mode shapes and damping ratios using moving vehicles sensor data.