Random Vibration Analysis of a Vehicle–Bridge Interaction System Subjected to Traveling Seismic Ground Motions Using Pseudo-excitation Method

MACHUNYAN,최동호 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.6

For long, multi-span bridges, traveling seismic waves arrive at diff erent bridge support points at diff erent times. To study this diff erence, random dynamic vibration analysis of a vehicle–bridge interaction system under traveling seismic ground motions was performed in the present paper. A vehicle model with 27 degrees of freedom is used, while three-dimensional Euler beams are used to model the track and the bridge. The equation of motion of the vehicle–bridge interaction system was established through the wheel-rail relationship. The expression of the standard deviation of the system vibrations and the running safety factor is derived by the pseudo-excitation method. The proposed method is validated by comparing random bridge vibrations using the Monte-Carlo method. As a case study, a Chinese-made electric multiple unit train running on a ten-span simply supported bridge is analyzed under track irregularities and seismic ground motions with consideration of the eff ects of diff erent train speeds, diff erent seismic intensities, and diff erent seismic wave propagation velocities. The results show that wave propagation velocities signifi cantly aff ect the random vibration performances and the running safety of the vehicle-bridge interaction system. Therefore, it is important to include wave propagation velocities when calculating the random seismic vibrations of a vehicle-bridge interaction system.

Finite element analysis of vehicle-bridge interaction by an iterative method

Jo, Ji-Seong,Jung, Hyung-Jo,Kim, Hongjin Techno-Press 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.30 No.2

In this paper, a new iterative method for solving vehicle-bridge interaction problems is proposed. Iterative methods have advantages over the non-iterative methods in that it is not necessary to update the system matrix for a given wheel location, and the method can be applied for a new type of car or bridge with few or no modifications. In the proposed method, the necessity of system matrices update is eliminated using the equivalent interaction force acting on the bridge, which is obtained iteratively. Ballast stiffness is included in the interaction forces and the geometric compatibility at the contact points are used as convergence criteria. The bridge is considered as an elastic Bernoulli-Euler beam with surface irregularity and ballast stiffness. The moving vehicle is modeled as a multi-axle mass-spring-damper system having many degrees of freedom depending on the number of axles. The pitching effect, which is the interaction effect between the rear and front wheels when a vehicle begins to enter or leave the bridge, is also considered in the formulation including extended ground boundaries having surface irregularity and ballast stiffness. The applicability of the proposed method is illustrated in the numerical studies.

Effect of road surface roughness on the response of a moving vehicle for identification of bridge frequencies

Yang, Y.B.,Li, Y.C.,Chang, K.C. Techno-Press 2012 Interaction and multiscale mechanics Vol.5 No.4

Measuring the bridge frequencies indirectly from an instrumented test vehicle is a potentially powerful technique for its mobility and economy, compared with the conventional direct technique that requires vibration sensors to be installed on the bridge. However, road surface roughness may pollute the vehicle spectrum and render the bridge frequencies unidentifiable. The objective of this paper is to study such an effect. First, a numerical simulation is conducted using the vehicle-bridge interaction element to demonstrate how the surface roughness affects the vehicle response. Then, an approximate theory in closed form is presented, for physically interpreting the role and range of influence of surface roughness on the identification of bridge frequencies. The latter is then expanded to include the action of an accompanying vehicle. Finally, measures are proposed for reducing the roughness effect, while enhancing the identifiability of bridge frequencies from the passing vehicle response.

Finite element analysis of vehicle-bridge interaction by an iterative method

Ji-Seong Jo,정형조,Hongjin Kim 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.30 No.2

In this paper, a new iterative method for solving vehicle-bridge interaction problems is proposed. Iterative methods have advantages over the non-iterative methods in that it is not necessary to update the system matrix for a given wheel location, and the method can be applied for a new type of car or bridge with few or no modifications. In the proposed method, the necessity of system matrices update is eliminated using the equivalent interaction force acting on the bridge, which is obtained iteratively. Ballast stiffness is included in the interaction forces and the geometric compatibility at the contact points are used as convergence criteria. The bridge is considered as an elastic Bernoulli-Euler beam with surface irregularity and ballast stiffness. The moving vehicle is modeled as a multi-axle mass-spring-damper system having many degrees of freedom depending on the number of axles. The pitching effect, which is the interaction effect between the rear and front wheels when a vehicle begins to enter or leave the bridge, is also considered in the formulation including extended ground boundaries having surface irregularity and ballast stiffness. The applicability of the proposed method is illustrated in the numerical studies.

Intelligent Human-Vehicle Interaction

Daesub Yoon,Kyongho Kim,Jonghyun Park 대한인간공학회 2011 대한인간공학회 학술대회논문집 Vol.2011 No.5

Objective: The aim of this study is to develop the adaptively intelligent human-vehicle interaction system to reduce drivers' cognitive and visual distraction for automotive industry. Background: With the proliferation of in-vehicle information systems, drivers are not easy to focus on driving tasks while they are driving due to distractions from various in-vehicle information systems such as navigators, mobile phone etc. To reduce these distractions, in-vehicle information system needs to be aware driving situations and to provide right information at the right time. Such a system can be categorized to intelligent human-vehicle interaction system. In this paper, we propose intelligent HVI systems and discuss principal components of HVI system. Method: The intelligent HVI system is composed of 4 main principal components; (1) drivers' and driving situation sensing technology, (2) drivers' and driving situation modeling (3) drivers' workload measurements and criterion and (4) multimodal interaction. Results: The development of the adaptively intelligent human-vehicle interaction system is a Korean government funded project [MKE, 10033312]. This project is ongoing projects and expected to be completed in 2014. Conclusion: We expect intelligent HVI systems can reduce driving accidents by minimizing drivers' distraction. Application: The results of these systems can be easily applied to automotive industry.

Design of the Integrated In-vehicle Interaction System

Jongwoo Choi,Hye Sun Park,Kyong-Ho Kim 대한인간공학회 2011 대한인간공학회 학술대회논문집 Vol.2011 No.5

The Information Technology devices provide a lot of useful information anywhere. Though the usefulness of the IT devices, they interfere with the driver's attention in driving situation. The integration of the in-vehicle interfaces is important to manage the interaction process of the in-vehicle electronic devices and provide the information safely. We consider about the in-vehicle interfacing system design method to make the system. The design of the integrated system is based on the main subject that interacts with the driver. This paper describes the better design to make the integrated system compatible and flexible. To develop the real in-vehicle interaction system, we classify the interaction from the existing IT devices, the navigation system and the mobile cellphone. The direct operation of the IT device is monitored by the integrated system to know the driver's action in driving situation, and the information from the IT device is managed to provide when/how the driver recognize. We will apply the system design method to develop the HVI(Human-Vehicle Interface) system to integrate the in-vehicle interaction.

Analysis of high-speed vehicle-bridge interactions by a simplified 3-D model

Song, Myung-Kwan,Choi, Chang-Koon Techno-Press 2002 Structural Engineering and Mechanics, An Int'l Jou Vol.13 No.5

In this study, the analysis of high-speed vehicle-bridge interactions by a simplified 3-dimensional finite element model is performed. Since railroads are constructed mostly as double tracks, there exists eccentricity between the vehicle axle and the neutral axis of cross section of a railway bridge. Therefore, for the more efficient and accurate vehicle-bridge interaction analysis, the analysis model should include the eccentricity of axle loads and the effect of torsional forces acting on the bridge. The investigation into the influences of eccentricity of the vehicle axle loads and vehicle speed on vehicle-bridge interactions are carried out for two cases. In the first case, only one train moves on its track and in the other case, two trains move respectively on their tracks in the opposite direction. From the analysis results of an existing bridge, the efficiency and capability of the simplified 3-dimensional model for practical application can be also verified.

Theoretical formulation for vehicle-bridge interaction analysis based on perturbation method

Yongchao Tan,Liang Cao,Jiang Li 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.2

A three-mass vehicle model including one rigid mass and two unsprung masses is adopted to predict the vehicle-bridge interaction (VBI) and to establish the nonlinear coupled governing equations. To overcome the numerical instability and large computation problems concerning the vehicle-bridge system, the perturbation method is used to convert the nonlinear coupled governing equations into a set of linear uncoupled equations. Formulas for bridge’s natural frequencies considering both the VBI and the dynamic responses of bridge and vehicle are proposed. Compared with the numerical results obtained by the Newmark-β method, the theoretical solutions for natural frequencies and dynamic responses are validated. The effects of the important factors of unsprung mass, vehicle damping, surface irregularity on the natural frequencies and dynamic responses of bridge and vehicle are discussed, based on the theoretical solutions.

Modelling and analysis of vehicle-structure-road coupled interaction considering structural flexibility, vehicle parameters and road roughness

Mehmet Akif Koç,İsmail Esen 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.5

To determine the dynamic forces acting on vehicle components a vehicle-structure-road interaction is considered. Coupled interaction was modelled using a flexible bridge-like thin beam structure with four and six Degree of freedom (DOF) half car models. In addition to the flexible structure, the road conditions were added to the model as random and non-random surface irregularities. A coupled equation of motion of the whole system was derived using Lagrange equations, and converted to a first-order state-space equation and then solved using the fourth-order Runge-Kutta method. Besides the dynamic forces, the effects of the vehicle speed, bridge flexibility, tire stiffness, random or non-random road irregularities on the passenger comfort are widely investigated. The results obtained were compared by several early VBI (Vehicle-bridge-interaction) studies in the literature and proved accurate with a 5 % difference.

A drive-by inspection system via vehicle moving force identification

OBrien, E.J.,McGetrick, P.J.,Gonzalez, A. Techno-Press 2014 Smart Structures and Systems, An International Jou Vol.13 No.5

This paper presents a novel method to carry out monitoring of transport infrastructure such as pavements and bridges through the analysis of vehicle accelerations. An algorithm is developed for the identification of dynamic vehicle-bridge interaction forces using the vehicle response. Moving force identification theory is applied to a vehicle model in order to identify these dynamic forces between the vehicle and the road and/or bridge. A coupled half-car vehicle-bridge interaction model is used in theoretical simulations to test the effectiveness of the approach in identifying the forces. The potential of the method to identify the global bending stiffness of the bridge and to predict the pavement roughness is presented. The method is tested for a range of bridge spans using theoretical simulations and the influences of road roughness and signal noise on the accuracy of the results are investigated.