Vibration Analysis Of Vehicle Research Articles

Railway vehicle vibration mechanism induced by offsetting axlebox suspension elements position

This paper describes railway vehicle vibration mechanism whereby offset suspension elements position affect bogieframe vibration response. Primary suspension elements are often set on offset position from center of axlebox, so we hypothesized that offset primary damper position trigger axlebox rotation around axlebox bearing, which play pivotal role in inducing bogie-frame pitching via coil spring. To address this hypothesis, we conducted whole vehicle vibration analysis, focusing on axlebox damper vertical damping force and coil spring horizontal force applied on the offset position from center of axlebox. Analysis results showed that the mechanisms are suggested to involve bogie-frame vibration response mediated by axlebox rotation as well as coil spring horizontal force.

Dynamic interaction analysis of suspended monorail vehicle and bridge subject to crosswinds

This paper develops a fully coupled wind-vehicle-bridge (WVB) interaction model to evaluate the dynamic performance and riding comfort of the suspended monorail vehicle-bridge system subject to turbulent crosswinds. The dynamic interactions between the vehicle and the bridge, the wind and the bridge, and the wind and the vehicle are considered in the model. The suspended monorail vehicle is modeled as a mass-spring-damper system and the motion equations of the multi-body system are derived. Through generating nonuniformity wind velocity fields consisting of various wind average velocities, an accurate approach to simulate the actual aerodynamic wind forces acting on the bridge and on moving vehicles is proposed. Further, a multi-span bridge is chosen as an example to illustrate the dynamic behaviors of the proposed WVB system. Results indicate that the turbulent crosswinds could have a great influence on the dynamic performance of the suspended monorail vehicle-bridge system, and it should be taken into account in the simulation of aerodynamic wind forces to guarantee the accurateness of vehicle vibration analysis. Besides, passengers could experience uncomfortable when vehicles pass through the bridge under strong turbulent crosswinds.

Automated Road Damage Recognition based on the Sparse Coding Analysis of Vehicle Vibrations

Road pavement damage inspection is a critical yet challenging task. At present, road pavement damage inspection is usually done by DOTs using a manual process. Another emerging method of inspection is via the use of sensors, such as the use of LiDAR. This study proposes an automated road damage recognition method via the Sparse Coding analysis of vehicle vibrations. Sparse Coding is a class of unsupervised methods that learn data patterns based on extracted overcomplete bases. Unlike frequency domain-based analysis, e.g. Spectral Analysis, Sparse Coding analysis preserves the temporal information of the vehicle vibration that contains important patterns related to road pavement damage. A preliminary study was performed with vehicle vibration data collected in College Station, Texas. Results confirm the feasibility of the proposed method in automated road pavement damage recognition. More data points should be collected in the future to further benchmark the effectiveness of the proposed method.

Nonlinear vibration analysis of vehicle–bridge interaction for condition monitoring

In this paper, we investigate vehicle–bridge interactions and propose a new method for assessing bridge conditions based on nonlinear vibration analysis. A vehicle model is presented, and the dynam...

Experimental Comparison of Vehicle Vibration Simulation Techniques

Abstract Performing accurate vehicle vibration simulation is imperative to understanding the adequacy of a packaged product's ability to withstand the rigors of transportation. Over the past decade, various vehicle vibration analysis techniques were proposed in order to provide better correlation to actual field shipments. This paper highlighted the observations made when an independent laboratory utilized four different methods in the simulation of vertical vibration and applied them to three different packaged products. A field data recorder was employed to record over-the-road vibration of a fully loaded steel spring truck traveling over interstates and highways. The collected data was analyzed independently using each of the different techniques and simulated in a lab with the necessary controller. This study is unique in that it considered the response of actual packaged products and through the use of a damage assessment tool, determined how well the techniques correlate with field vibration results. Additionally, two common industry vibration profiles were used to test the packaged products for comparison. The three packaged products used for these evaluations were a top-mount refrigerator, an electric hedge trimmer, and a gas-powered pressure washer. Results indicate that each of the proposed vehicle vibration analysis techniques produces product and package damage that correlates well with typical field vibration results for the three products tested. These results supported the further use of any of these techniques in the simulation of vehicle vibration.

English

Performing accurate vehicle vibration simulations is imperative to understanding the adequacy of a packaged product’s ability to withstand the rigors of transportation. Over the past several years, various vehicle vibration analysis techniques have been proposed in order to provide better correlation to actual field shipments. Some of these new techniques allow for the vibration data collected to be analyzed in a manner that reduces the duration of the laboratory vibration simulation. This paper discusses the discoveries made when an independent laboratory utilized these techniques to reduce test durations for vertical vibration simulation. A field data recorder was employed to collect and record over-the-road vibration of a fully loaded steel spring truck traveling over interstates and highways. The collected data was analyzed independently for each of the different simulation techniques and the resulting simulations were conducted using a servo-hydraulic vibration table. This paper is unique in it evaluates the simulation techniques using actual packaged products, and by use of a damage assessment tool, determines how well the techniques correlated with actual field study results. The three packaged products used for these evaluations were as follows: top-mount refrigerator, electric hedge trimmer, and gas powered pressure washer. Results indicate it is possible to reduce the vibration test durations during vertical vibration simulation, while still correlating with results collected from field studies.

Vertical random vibration analysis of vehicle–track coupled system using Green's function method

A vertical vehicle–track coupled dynamic model, consisting of a high-speed train on a continuously supported rail, is established in the frequency-domain. The solution is obtained efficiently by use of the Green's function method, which can determine the vibration response over a wide range of frequency without any limitations due to modal truncation. Moreover, real track irregularity spectra can be used conveniently as input. The effect of the flexibility of both track and car body on the entire vehicle–track coupled dynamic response is investigated. A multi-body model of a vehicle with either rigid or flexible car body is defined running on three kinds of track: a rigid rail, a track stiffness model and a Timoshenko beam model. The results show that neglecting the track flexibility leads to an overestimation of both the contact force and the whole vehicle vibration response. The car body flexibility affects the ride quality of the vehicle and the coupling through the track and can be significant in certain frequency ranges. Finally, the effect of railpad and ballast stiffness on the vehicle–track coupled vibration is analysed, indicating that the stiffness of the railpad has an influence on the system in a higher frequency range than the ballast.

Analysis of Vehicle Vibrations – New Approach to Rating Pavement Condition of Urban Roads

Urban road infrastructure is daily burdened by heavy traffic volume. Pavement structure roughness observations are significantly more difficult in urban agglomerations than on roads in unpopulated areas. Roughness, expressed by IRI (International Roughness Index), directly affects the quality and safety of road traffic. Within the framework of the pavement management in relation to safety and the achievement of the best possible ride comfort, it is very important to foresee when a road should be reconstructed. The method for quality evaluations of safety and ride comfort on urban roads presented in this paper is based on vehicle vibrations measurements. In the article, measuring of vehicle vibrations was performed on the main urban roads in Zagreb (Croatia). Measurements covered roads with different pavement surface roughness. This method can be simply and very easily used in pavement management aimed at achieving road safety and better ride comfort. The results of measurements according to this method could be used by traffic and civil engineering experts as an indication for the roads that require reconstruction or maintenance. KEY WORDS: urban roads, traffic flow, safety, vehicle vibrations, road surface roughness (IRI)

Vehicle Vibration Analysis in Changeable Speeds Solved by Pseudoexcitation Method

The vehicle driving comfort has become one of the important factors of vehicle quality and receives increasing attention. In this paper, the mechanical and mathematical models of the half-car, five degrees of freedom (DOF) of a vehicle were established, as well as the pseudoexcitation model of road conditions for the front wheel and the rear wheel. By the pseudoexcitation method, the equations of transient response and power spectrum density were established. After numerical simulation to vehicle vibration response of changeable driving, the results show that the pseudoexcitation method is more convenient than the traditional method and effectively solves the smoothness computation problems of vehicles while the pseudoexcitation method is used to analyze vehicle vibration under nonstationary random vibration environments.

Modified HHT Method Usage for Vehicle Vibration Analysis in Time Domain

The paper deals with the analysis of vehicle vibrations in the time domain. The main aim is to modify the HHT-method for the solution of mechanical systems with nonlinear members. The modification enables the computation with the constant system computational matrix. This causes that the triangulation is to be performed once only and the nonlinear members affect only the right side of the algebraic equations system. This can dramatically decrease the time consumption of the computation. We used the method modified in this way for the dynamic analysis of the model with the parameters of the specimen "ERRI - vehicle" that was kinematically excited.

Symplectic analysis of vertical random vibration for coupled vehicle–track systems

A computational model for random vibration analysis of vehicle–track systems is proposed and solutions use the pseudo excitation method (PEM) and the symplectic method. The vehicle is modelled as a mass, spring and damping system with 10 degrees of freedom (dofs) which consist of vertical and pitching motion for the vehicle body and its two bogies and vertical motion for the four wheelsets. The track is treated as an infinite Bernoulli–Euler beam connected to sleepers and hence to ballast and is regarded as a periodic structure. Linear springs couple the vehicle and the track. Hence, the coupled vehicle–track system has only 26 dofs. A fixed excitation model is used, i.e. the vehicle does not move along the track but instead the track irregularity profile moves backwards at the vehicle velocity. This irregularity is assumed to be a stationary random process. Random vibration theory is used to obtain the response power spectral densities (PSDs), by using PEM to transform this random multiexcitation problem into a deterministic harmonic excitation one and then applying symplectic solution methodology. Numerical results for an example include verification of the proposed method by comparing with finite element method (FEM) results; comparison between the present model and the traditional rigid track model and; discussion of the influences of track damping and vehicle velocity.

Time-domain simulation and nonlinear analysis on ride performance of four-wheel vehicles

A nonlinear dynamic model with eight DOFs of a four-wheel vehicle is established in this paper. After detaching the nonlinear characteristics of the leaf springs and shock absorbers, the multi-step linearizing method is used to simulate the vehicle vibration in time domain, under a correlated four-wheel road roughness model. Experimental verifications suggest that the newly built vehicle model and simulation procedure are reasonable and feasible to be used in vehicle vibration analysis. Furthermore, some nonlinear factors of the leaf springs and shock absorbers, which affect the vehicle ride performance (or comfort), are investigated under different vehicle running speeds. Some substaintial rules of the nonlinear vehicle vibrations are revealed in this paper.

The evolution of test instrumentation: From rack and stack to plug and play

Electronic test instrumentation for acoustics and vibration measurement has seen radical changes during the final decade of the 20th century. From analog to digital to PC based, the performance, flexibility and ease of use have risen while the price per performance has declined. Taking advantage of the rapid developments in PC operating systems, mass marketed microprocessors, and the professional audio industry, todays instrumentation frequently has more in common with both the recording studio and the home computer than with the physics laboratory. The future promises even more as this evolution continues. Two examples, vehicle vibration analysis and electroacoustic testing, are used as examples to follow the development of test platforms. The advantages (and disadvantages) of software-based testing are discussed, and some insights of what the new decade might offer are provided.

Probabilistic analysis of vehicle vibrations

The dynamical analysis of random vehicle vibrations requires an integrated investigation of guideway roughness, nonlinear vehicle dynamics and human sensation to vibration exposure. The stochastic analysis of the total system is discussed in the frequency domain and the time domain. Nonlinearities are considered by statistical linearization techniques. Then, the variances of wheel load variation, car body acceleration and human sensation are determined by spectral density analysis as well as by covariance analysis.