Vehicle Vibration Research Articles

Constitutive relation expansion of large load metal rubber engine mount stress bivariate function relationship using the strain and strain rate

Metal rubber materials were first used for vibration cushioning and noise protection applications in aviation equipment. With the recent developments in science and technology, metal rubber materials have been gradually implemented in Vehicle Vibration Suppressing. Metal rubber has significant advantages over ordinary rubber materials, in terms of its vibration damping in extreme environments. Along these lines, the objective of this work was to develop a mechanical model of metal rubber mount for mining vehicles, which can be used to predict the equivalent stress change of large load metal rubber mount in actual operation. Starting from the mechanical model of the mount and then expanding the macroscopic one-dimensional relationship of force and displacement to the binary relationship between the force and displacement and velocity, the microscopic one-dimensional relationship of stress and strain was expanded to the binary relationship between the stress and strain and strain rate. This work focused on the three-dimensional intrinsic structure model of stress, strain, and strain rate for metal rubber mounts. Moreover, the mechanical properties of the metal rubber mounts were explored in conjunction with the Mooney–Rivlin model, while the constitutive relationship of its stress, strain, and strain rate was deduced. The three-dimensional hysteresis curves were plotted by using software simulation analysis of the metal rubber mounts, and the metal rubber mounts hysteresis surface was also fitted. A combination of simulated and experimental data was used to test the accuracy of the proposed mechanical model of the metal rubber mount. From the acquired results, it was demonstrated that the errors of the relevant parameters (c10,c01, and c11) of the mechanical model of the metal rubber mount were about 10%. On top of that, the errors of the simulated stiffness values and the damping ratios of the metal rubber mount and the experimental stiffness values and damping ratios were within 10%. Excluding the interference of the metal rubber mount fabrication error, the proposed mechanical model met the mechanical analysis of the metal rubber mount with a large load and the mechanical model was accurate. The influence of the strain and strain rate on the stiffness and damping of the metal rubber mounts was also clarified, and the expansion method of the constitutive relationship of the metal rubber mount stress and strain was systematically explored. From the analysis of the metal rubber mounts’ mechanical properties, a reference basis for its vibration analysis and for the mechanical analysis of other nonlinear materials was provided.

Proposing an original control algorithm for the active suspension system to improve vehicle vibration: Adaptive fuzzy sliding mode proportional-integral-derivative tuned by the fuzzy (AFSPIDF)

Stimulation from the road surface can cause vehicle vibrations. Vehicle vibration is evaluated based on the change of displacement and acceleration values of the vehicle body. In order to improve ride comfort, an active suspension system should be used. This article proposes a new method for controlling the functioning of the active suspension system. The AFSPIDF algorithm was designed based on PID, SMC, and Fuzzy algorithms. The PID algorithm is only applicable to SISO objects with linear oscillations. The SMC algorithm can be applied to nonlinear systems; however, a chattering phenomenon can still occur. Meanwhile, a Fuzzy algorithm can increase the flexibility of control states. Therefore, combining all three of these algorithms is necessary to become a new integrated control algorithm. The input signal of the Fuzzy algorithm is the output signal of the SMC algorithm. Besides, the PID controller parameters are also adjusted by another Fuzzy algorithm. These two Fuzzy algorithms operate in complete isolation from one another. This is a wholly new and unique algorithm. With two specific cases, the numerical simulation method explores vehicle vibration. In each case, four situations are compared. The results of the simulation process have shown that the values of displacement and acceleration of the vehicle body are significantly reduced once the AFSPIDF algorithm is used. In the first case, these values do not exceed 2.5% compared with vehicles using passive suspension systems. In the second case, these values do not exceed 13.5%. As a consequence, the stability and comfort of the vehicle have been greatly enhanced.

Study on Vehicle Vibration Response under the Condition of 3D Tire–Pavement Contact for Unmanned Driving

Unmanned driving is the direction of future development in the field of transportation. The development of unmanned driving will cause sensor monitoring and machine control to play a greater role. According to road roughness data collected by unmanned ground vehicles and vehicle dynamics, it is of great significance to establish a vehicle–pavement coupling model to analyze and guide driving comfort, cargo safety, and road friendliness. Pavement roughness is the main external excitation in the process of driving a vehicle. Therefore, a three-dimensional (3D) model of pavement roughness was constructed based on fractal theory and fractal interpolation. According to tire–pavement contact characteristics, a newly rerevised 3D flexible roller contact tire model was proposed. On this basis, vehicle vibration dynamics models for a car and a truck were established. The traditional point contact model was used to verify the model. Based on the comfort threshold of a passenger, the cargo vibration threshold, and the dynamic load coefficient (DLC) threshold of the truck, the conditions for ride comfort of an unmanned ground vehicle were expounded. The results showed that, compared with an ideal fully flat road surface, pavement roughness had a great impact on vehicle vibration. The 3D model of pavement roughness generated had high accuracy. The vehicle–pavement coupling model based on tire–pavement 3D contact under 3D pavement roughness excitation was correct. The proposed model can calculate vibration characteristics of passengers and cargo and the DLC of wheels in real time. For different types of vehicles and different roughness levels of pavement, different speed thresholds were given to ensure driving comfort, cargo safety, and road friendliness. Driving speed and each evaluation index met the Fourier function relationship. Partial correlation analysis showed that in order to ensure the comfort of passengers, more attention should be paid to pavement roughness, and for cargo safety and road friendliness, pavement roughness and vehicle speed should be considered at the same time. The results provide theoretical suggestions for the comfortable driving of future unmanned ground vehicles.

Study on Beat Vibration of a High Temperature Superconducting EDS Maglev Vehicle at Low Speed

Vertical displacement acceleration and the pitch angle record produce the phenomenon of beat vibration when testing a 200 m electro-dynamic suspension (EDS) magnetic levitation (maglev) test vehicle with high-temperature superconducting (HTS) at the CRRC Changchun Railway Vehicles Co., Ltd., where the vehicle is clamped and in planar motion. First, to examine this phenomenon, this paper establishes dynamic equations of the vehicle with three degrees of freedom (DOF), and the levitation force on each superconducting magnet (SCM) is calculated by dynamic circuit theory. Second, the theory vertical equilibrium point is obtained from the average of the levitation force for a different velocity and the magneto-motive force (MMF) of the SCM. Third, this paper decouples SCM levitation forces from each other using MATLAB/SIMULINK, and a multi-body dynamic model with six DOF is developed in SIMPACK. All vertical displacements and acceleration responses, as well as the pitch angle and acceleration response from the simulation, appear to show the phenomenon of beat vibration since there are two closing natural frequencies of approximately 2 Hz and 2.4 Hz. Finally, based on the traversing method considering the influence of the velocity, initial vertical displacement, and the MMF of the SCM, the multi-body dynamic model is frequently utilized to study the response of the mean and amplitude of vertical displacement and that of the pitch angle. The results show that increasing the MMF or velocity could decrease the vertical displacement and pitch angle; the mean vertical displacement is a little larger than the theory equilibrium point; and the amplitude of vertical displacement is small when the initial vertical displacement is near the theory equilibrium point. Both the numerical and experimental results verify the validity of the dynamic circuit model and mechanical model in this paper.

Numerical Verification of the Drive-By Monitoring Method for Identifying Vehicle and Bridge Mechanical Parameters

The PRE (numerical simulation-based vehicle and bridge parameter and road roughness estimation) method uses vehicle vibration data to identify the vehicle’s and bridge’s mechanical parameters and estimate road unevenness simultaneously. This method randomly assumes the mechanical parameters first. Secondly, it solves the vehicle’s IEP (input estimation problem) and the bridge’s DRS (dynamic response simulation) from the vehicle vibration data to obtain road profiles of the front and rear wheels. Repeat the random assumption of the mechanical parameters to minimize the residual between the obtained road unevenness because the road unevenness of the front and rear wheels are expected to match. To search for a better combination of the mechanical parameters, the MCMC (Monte Carlo Markov chain) algorithm is adopted in this paper. This paper also numerically simulates vehicle vibration data for the cases of the reduced-stiffness bridge model and examines whether this method can identify the position, range, and magnitude of stiffness reduction. The numerical simulation results show that bridge-stiffness reduction can be estimated reasonably.

Mechanism analysis and optimum control of negative airgap eccentricity effect for in-wheel switched reluctance motor driving system

In this paper, the generation mechanism of the negative airgap eccentricity effect for the in-wheel switched reluctance motor (SRM) driving system is analyzed. An independent current chopping control strategy is proposed to achieve optimum control between the response characteristic of the in-wheel motor driving system and the dynamic performance of electric vehicle (EV). Firstly, the electromagnetic characteristic of the studied SRM under airgap eccentricity is studied based on electromagnetic coupling model and circuit driving equation, and the radial electromagnetic force under different airgap eccentricity is verified by adopting the built experiment device. Then, combined with the excitation characteristics of the radial electromagnetic force, the negative dynamic effect of the in-wheel motor driving system is analyzed in the time–frequency domain. Finally, an independent current chopping control strategy for the in-wheel SRM driving system based on vehicle vibration feedback is proposed. The controller parameters including the turn-off angle and chopping current threshold are optimized by data interpolation. Results show that the proposed control strategy can achieve the optimum control between the response characteristics of the in-wheel motor driving system and the vehicle dynamic performance, especially to suppress the vehicle sprung mass acceleration and tire bounce while starting EV.

Numerical Modeling of the Low-Medium Frequency Vibration and Acoustic Radiation of Underwater Vehicles

_ Considering the main structures of typical underwater vehicles, three types of numerical model are established, including the beam model, the shell-beam model, and the whole shell model. The results of the three models are compared during the analyses of global vibration, local vibration of cabins, and underwater acoustic radiation. Giving consideration to both the computational cost and accuracy, the proposed shell-beam model is appropriate for the calculation of low-medium frequency acoustic radiation of the main structures of underwater vehicles. The rationality and the frequency range of application of the shell-beam model are verified by calculating the fluid-structure coupling vibration response and the underwater acoustic radiation of the hull subjected to the transverse load excitation, which also demonstrate the significance of this model in engineering practice. Introduction The calculation research on the acoustic radiation of typical underwater vehicle structures can be generally divided into three types based on the calculation methods: analytical methods (Caresta & Kessissoglou 2009), numerical methods, and analytical-numerical hybrid methods (Zhu et al. 2014; Meyer et al. 2016; Qu et al. 2017). The analytical methods can be used for the study of basic laws and mechanisms, and can also be treated as benchmarks for numerical algorithms. However, when it comes to real ships with complex structures, it is difficult to accurately predict the forced vibration and underwater acoustic radiation characteristics by analytical methods. Previously, due to the limitation of the computer hardware, a whole ship was usually simplified as a free–free beam of variable cross section (the hull beam) when conducting the analysis of global vibration. In recent years, with the development of computer technology, whole shell models are usually established during analyses of the low-medium frequency vibration and acoustic radiation of underwater vehicles.

Effect of suspension form on the vehicle-bridge coupled vibration of the maglev vehicle

In order to find out the influence of suspension form on the medium and low-speed maglev system, first, the transfer functions of the heaving and pitching motions of the two kinds of levitation modules equipped with the two suspensions, respectively, were derived and compared. Second, the coupled-vibration equations of the levitation module, cabin and bridge were presented. At last, two kinds of dynamic models were built to analyse the dynamic performance of the two maglev vehicles. Results show that the effect of the suspension form on the levitation module response is significant, but that on the cabin and bridge is insignificant. The maximum air-gap fluctuation in MVES (maglev vehicle with end-mounted suspension) is about twice that in MVMS (maglev vehicle with mid-mounted suspension) at the speed of 160 km/h. Moreover, the maximum current in MVES is 7.4 A larger than that in MVMS, and the mean power consumption of the levitation system in MVES is 1.2 kW larger than that in MVMS. On the whole, according to the dynamic responses of the two maglev vehicles, the mid-mounted suspension is more conducive to reducing the air-gap fluctuation, current and power consumption of the levitation system.

Research on longitudinal vibration suppression of underwater vehicle shafting based on particle damping

A particle damper is applied to suppress the longitudinal vibration of underwater vehicle shafting in order to reduce vibration level and improve silence and stealth of underwater vehicles. The model of rubber-coated steel particle damper was established with discrete element method and PFC3D simulation software, the damping energy consumption law of collision and friction between particle and damper and between particle and particle investigated, the effects of particle radius, mass filling ratio, cavity length, excitation frequency, excitation amplitude, rotating speed and both stacking and motion states of particles on the system vibration suppression were discussed, and the bench test was carried out to verify the law. It revealed the mechanism of longitudinal vibration suppression of particle damping, established the intrinsic relationship between of total energy consumption of particle and vibration of system, and put forward the evaluating method of longitudinal vibration suppression effect by total energy consumption of particle and vibration reduction ratio. The research results show that the mechanical model of particle damper is reasonable and the simulation data is reliable; the rotating speed, mass filling ratio and cavity length have significant effects on the total energy consumption of particle and vibration reduction ratio.

Pavement Roughness Grade Recognition Based on One-dimensional Residual Convolutional Neural Network.

A pavement's roughness seriously affects its service life and driving comfort. Considering the complexity and low accuracy of the current recognition algorithms for the roughness grade of pavements, this paper proposes a real-time pavement roughness recognition method with a lightweight residual convolutional network and time-series acceleration. Firstly, a random input pavement model is established by the white noise method, and the pavement roughness of a 1/4 vehicle vibration model is simulated to obtain the vehicle vibration response data. Then, the residual convolutional network is used to learn the deep-level information of the sample signal. The residual convolutional neural network recognizes the pavement roughness grade quickly and accurately. The experimental results show that the residual convolutional neural network has a robust feature-capturing ability for vehicle vibration signals, and the classification features can be obtained quickly. The accuracy of pavement roughness classification is as high as 98.7%, which significantly improves the accuracy and reduces the computational effort of the recognition algorithm, and is suitable for pavement roughness grade classification.

Hydraulic Vehicle Damper Controlled by Piezoelectric Valve.

In this paper, an original construction of a vehicle vibration damper controlled by means of a valve based on piezoelectric actuator is presented and investigated. The presented valve allows us to control dissipation characteristics of the damper faster than in other solutions adjusting the size of the gap through which the oil flows between the chambers of the damper. The article also presents the results of the experimental investigation of the above-mentioned damper showing the possibility of changing the value of the damping force five times in about 10 ms by changing the voltage supplying the piezoelectric actuator. Based on these results, dissipative characteristics were determined which enabled the identification of the parameters of the damper numerical model. The article also presents the results of numerical investigations a vehicle model equipped with the developed dampers. The results showed that the developed damper controlled by the use of the piezoelectric actuator can significantly affect vehicle traffic safety by reducing the variation of vertical forces acting on the wheels. The results obtained are so promising that the authors undertook preparations to conduct road tests of a vehicle equipped with the developed dampers.

Optimal placement criteria of hybrid mounting system for chassis in future mobility based on beam-type continuous smart structures

Recently, research into the development of hybrid and electric vehicles has been vigorously undertaken, indicating a trend toward the replacement of internal combustion engine vehicles. However, while high efficiency and light weight are crucial in the development of vehicles, they increase the excitation force of the engine. In addition, sensor placement in future mobility is very important since it causes malfunctioning of autonomous driving systems when the location and orientation of sensors are changed due to excessive vehicle vibration. To reduce the structure-borne noise and vibration caused by engine excitation, an active engine mounting system must be installed in an optimal location. Thus, in this study, to determine the optimal location for an active engine mounting system applied to a beam structure, a series of simulations with two different methodologies are performed. The overall beam structure with two active mounting systems is modeled based on the lumped parameter model. To determine the optimal position of the active mounting system, it is moved to equal intervals, and the force and phase of the active mounts at each location combination are calculated based on static and dynamic methods. The optimal position is suggested such that the vibration reduction is maximized, while the applied force is minimized. Additionally, a feasibility experiment is conducted to validate the proposed criteria and confirm the simulation results. The results demonstrate that the optimal location of the active engine mounting system with a minimized force requirement and maximized vibration reduction can be identified.

Vehicle Dynamics and Train-Induced Ground Vibration—Theoretical Analyses and Simultaneous Vehicle, Track, and Soil Measurements

Ground vibrations near railway lines are generated by the forces that are acting between wheel and rail. It seems to be a straight forward assumption that the vehicle dynamics are important for the level and the frequencies of the excitation forces. Different vehicle dynamics phenomena are analysed for their role in the excitation of ground vibrations: rigid body modes of the bogies, elastic (bending) modes of the car body, and elastic modes of the wheelset. The theoretical analyses use rigid body models, simplified elastic models, and detailed elastic models. Some of these problems are vehicle–track interaction problems where 3D finite-element boundary-element models have been used for the track and soil. It is shown that the rigid or flexible vehicle modes are well in the frequency range of ground vibrations (4 to 100 Hz). They have an influence on the excitation force but the additional forces are rather small and can be neglected in ground vibration prediction. The theoretical results are checked by experimental results of a simultaneous measurement of vehicle, track, and ground vibrations.

Identification method for subgrade settlement of ballastless track based on vehicle vibration signals and machine learning

High-frequency train loads and complex environmental factors over a long period will inevitably cause subgrade settlement, an issue that adversely affects line smoothness. The existing monitoring methods are inefficient, manpower consuming and small in scope. This paper takes the subgrade settlement disease of the double-block ballastless track as the research object and proposes a subgrade settlement identification method based on vehicle vibration signals. In addition, it establishes a vehicle-track-subgrade vertical coupling model that combines feature extraction with algorithms such as support vector machines (SVMs) and convolutional neural networks (CNNs) to accurately identify subgrade settlement diseases on ballastless tracks. The results show: I) the subgrade settlement is far more impactful than fastener failure and debonding of the supporting layer on the vehicle vibration, with the main frequency band concentrated in 0 to 10 Hz, and the vertical vibration acceleration of the vehicle body and bogie can be used as a sensitive feature to identify ballastless track subgrade settlement, II) both the particle swarm optimization (PSO)-SVM and CNN-SVM algorithms can effectively determine the existence of subgrade settlement and the values of the settlement wavelength and amplitude. Both algorithms run a 100 % identification of subgrade settlement, with the lowest identification rates of settlement wavelength being 97.56 % and 100 %, respectively and the lowest identification rates of amplitude being 84.78 % and 97.56 %, respectively. In general, the overall accuracy of the CNN-SVM always outperforms PSO-SVM, and III) changes to the vehicle passing speed will create a more obvious interference effect on the identification of the settlement amplitude. For the PSO-SVM algorithm, the identification rate for the amplitude has a difference of up to 8.70 %, while this is 2.44 % for the CNN-SVM algorithm, indicating the CNN-SVM algorithm is more robust than the PSO-SVM algorithm.

Estimating the Tire–Pavement Grip Potential From Vehicle Vibrations

This study was motivated by the desire to provide highway managers/operators with more frequent and spatially dense information about the prevailing friction conditions in their networks. A new data-driven method was outlined for this purpose, wherein the prevailing tire–pavement grip potential is estimated from vehicle vibrations recorded during normal/regular usage of the infrastructure. The method was based on the underlying premise that transverse vehicle accelerations are related to wheel side-force oscillations, and therefore carry information related to the ride surface texture. It involved performing a short-time Fourier transform over vibration signals and analyzing the resulting spectral amplitudes. Two field experiments were carried out to validate the method. The first provided evidence of a statistical link between transverse vehicle vibrations and wheel side-force oscillations. The second tested the statistical link between skid resistance measured over a 26 km highway section and corresponding skid resistance estimations based on vehicle vibration data. Overall, transverse vehicle vibration characteristics were found to hold relevant information about the prevailing tire–pavement grip potential; the two were moderately inter-correlated. The newly proposed estimation method seems promising and potentially useful for pavement management applications, especially when considering the emergence of connected car technologies and the increased availability (and affordability) of in-vehicle Internet of Things devices.

Surface wave exploration technology for the tunnel overlying strata with vehicle vibration source

Subway tunnels are often built under the arterial roads in cities and the safety of overlying strata is important. Due to the limitation of urban space, many geophysical exploration methods maybe not be applicable. Most of the near surface exploration are carried out along the roads. This makes the continuously moving sources, including the vehicle and metro, to become important passive sources in the seismic detection. This type of signal has the characteristics of wide distribution, strong amplitudes, easy collection, and strong correlation. It carries abundant near-surface information and has high potential in non-destructive detection and monitoring. We obtain both the S-wave and P-wave profile with vehicle signals. Firstly, we propose an efficient method for equidistant linear array to extract the dispersion curves. The multiple vehicles signals were simulated with path integration method and the extracted dispersion curve has a good agreement with the theoretical data. In engineering and petroleum exploration, the P-wave velocity is more important than S-wave velocity sometimes. Previous study has shown that Poisson’s ratio is sensitive to the wavelength (W)-depth (D) relationship. Based on this observation, we proposed an inversion method to estimate the P-wave velocity structures directly. The traditional method is improved by adding the W/D-D information to the objective function, which is more sensitive to superficial layers. We select a high unevenness road above the operating subway. The vehicle signals are recorded along the roadside and the dispersion data is extracted. The inverted S-wave velocity profile can be used to identify warning geological positions such as water-rich weak interlayers. The resulting P-wave profile is also consistent with the drilling data. Our work successfully proves the effectiveness of vehicle signals and maps the overlying layers profile of subway tunnel.

Non-uniform wind excitation on dynamic responses of vehicle running on bridge

In order to investigate the effect of wind non-uniform characteristics in mountainous terrain on the dynamic analysis of a vehicle-bridge (VB) system, a typical bridge site for a terrain model was established in a wind tunnel. Six typical flow directions, such as parallel to the river direction and perpendicular to bridge axis and ridge, were adopted to study the mean wind speed of experimental monitoring points at the bridge deck. Owing to the local ridge at the bridge site, the distribution of wind speed along the bridge deck shows obvious non-uniform characteristics. Seven monitoring points were set on the bridge deck, and the linear interpolation method was adopted to obtain the time histories of the wind speed at every point. A scaled wind tunnel model was also applied to conduct the three aerodynamic coefficients of the vehicle and bridge. Based on the experimental wind characteristics of mountainous terrain, the numerical framework of the wind-vehicle-bridge (WVB) system was established considering the effect of non-uniform wind, where a railway cable-stayed bridge was simulated using the finite element model, and a multi-body dynamic model of the vehicle was used. The influence of fluctuating wind excitation on the WVB system was discussed, and it played an essential role in vehicle vibration.

Impacts of train-induced dynamic loads on goaf foundation of Qinshui coalfield

For the high-speed railway built in the goaf sites, if the influence depth of the additional loads reaches the collapse fault zone of the goaf foundation, the overburden rock mass above the mined area will move again, causing the surface to deform again, which seriously threatens the construction, operation, and maintenance of the high-speed railway lines. Therefore, in order to improve the safety and stability of operation of high-speed railway in goaf sites, it is essential to determine the activation deformation of the goaf foundation. In this paper, based on the additional stress method, the newly added embankment materials are taken as uniformly distributed strip static loads, and the high-speed railway in operation is regarded as the fluctuation-concentrated dynamic loads. The 1/4 vehicle vibration model with two degrees of freedom is introduced, and the influence depth of the additional loads of the goaf foundation is calculated. The criterion of activation is proposed based on the relationship between the influence depth of additional loads and the height of the collapse zone and fault zone. Conclusions drawn are as follows: i) the activation judgment criterion for the goaf foundation under the influence of high-speed railway vibration loads is recommended; ii) case study shows that the rail surface vibration model applicable to quantify the influence depth of high-speed railway mentioned previously mined-out regions; iii) the influence of rail surface irregularity on influence depth cannot be ignored; iv) the research conclusion can provide reference for site selection of high-speed railway and embankment deformation analysis.

Active Mitigation Strategy of Structure-Borne Vibration with Complex Frequency Spectra from Asymmetric Plate-like Mounting Systems in Next Generation Mobilities

The complicated spectrum produced by electric and hybrid car engines is particularly sensitive to the mid-frequency range. Furthermore, sensor placement in future mobility is crucial because when the positions and orientations of sensors are altered by excessive vehicle vibration, it results in the malfunctioning of autonomous driving systems. Smart structure-based active mounting approaches have been developed to reduce engine-induced vibration. These are made to continually adjust the mounts’ dynamic properties and enhance their performances in terms of noise, vibration, and harshness (NVH) under diverse operating circumstances. It can take the place of the engine support system’s current mount technique. The performance of the source part for reducing vibration when the structure is triggered by a sinusoidal and multi-frequency signal is the main subject of this study. The overall structure, which has two active mounts based on the source-paths-receiver structure, was modeled using a lumped parameter model. In the source section, sinusoidal, amplitude modulation (AM), and frequency modulation (FM) signals were used in order to assess the effectiveness of vibration reduction in the mid-frequency band. The normalized least mean-square (NLMS) technique was utilized to assess the effectiveness of an active mounting system, and a tracking signal was employed as a control signal. The algorithm was further expanded to the multi-NLMS algorithm to monitor the complex spectral signal. This demonstrates how an active mounting system can successfully reduce vibrations when the structure is activated by many mid-frequency complex signals.

Discussion on a Vehicle–Bridge Interaction System Identification in a Field Test

For infrastructures to be sustainable, it is essential to improve maintenance and management efficiency. Vibration-based monitoring methods are being investigated to improve the efficiency of infrastructure maintenance and management. In this paper, signals from acceleration sensors attached to vehicles traveling on bridges are processed. Methods have been proposed to individually estimate the modal parameters of bridges and road unevenness from vehicle vibrations. This study proposes a method to simultaneously estimate the mechanical parameters of the vehicle, bridge, and road unevenness with only a few constraints. Numerical validation examined the effect of introducing the Kalman filter on the accuracy of estimating the mechanical parameters of vehicles and bridges. In field tests, vehicle vibration, bridge vibration, and road unevenness were measured and verified, respectively. The road surface irregularities estimated by the proposed method were compared with the measured values, which were somewhat smaller than the measured values. Future studies are needed to improve the efficiency of vehicle vibration preprocessing and optimization methods and to establish a methodology for evaluating accuracy.